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  • 1.
    Barzegar, Hamid Reza
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Larsen, Christian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Jia, Xueen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Edman, Ludvig
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Palladium nanocrystals supported on photo-transformed C-60 nanorods: effect of crystal morphology and electron mobility on the electrocatalytic activity towards ethanol oxidation2014Ingår i: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 73, s. 34-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on the synthesis and decoration of high-aspect-ratio crystalline C-60 nanorods (NRs) by functionalized palladium nanoparticles with an average size of 4.78 +/- 0.66 nm. In their pristine form, C-60 NRs suffer from partial damage in the solution-based decoration process resulting in poor crystallinity. However, by modifying the NR surface via in situ photochemical transformation in the liquid state, we are able to prepare highly stable NRs that retain their crystalline structure during the decoration process. Our method thus opens up for the synthesis of highly crystalline nanocomposite hybrids comprising Pd nanoparticles and C-60 NRs. Bys measuring the electron mobility of different C-60 NRs, we relate both the effect of electron mobility and crystallinity to the final electrocatalytic performance of the synthesized hybrid structures. We show that the photo-transformed C-60 NRs exhibit highly advantageous properties for ethanol oxidation based on both a better crystallinity and a higher bulk conductivity. These findings give important information in the search for efficient catalyst support.

  • 2.
    Bi, Zenghui
    et al.
    School of Electronic Communication Technology, Shenzhen Institute of Information Technology, Shenzhen, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Materials and Energy, Yunnan University, Kunming, China.
    Wang, Yuwen
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Materials and Energy, Yunnan University, Kunming, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Zhang, Xianxi
    School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Wang, Xinzhong
    School of Electronic Communication Technology, Shenzhen Institute of Information Technology, Shenzhen, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Materials and Energy, Yunnan University, Kunming, China.
    Three dimensional star-like mesoporous nitrogen-doped carbon anchored with highly dispersed Fe and Ce dual-sites for efficient oxygen reduction reaction in Zn-air battery2022Ingår i: Colloid and Interface Science Communications, ISSN 2215-0382, Vol. 49, artikel-id 100634Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metal‑nitrogen‑carbon materials (M-N-C) have attracted much attention due to their low cost, high abundance, and efficient catalytic performance. Nevertheless, Fe-N-C materials are considered the most promising oxygen reduction reaction (ORR) catalysts for replacing noble metals. Ce is chemically active and has many metal valence states, and empty orbitals that can participate in coordination. On this basis, Fe, Ce-codoped catalyst was constructed in this study. The synergistic effect of the dual metal centers was verified, and a Fe, Ce-codoped nitrogen-doped carbon (FeCeNC) with six equal branch angles was proposed. The half-wave potential for the ORR catalyzed by FeCeNC is 0.855 V. As a rechargeable Zn-air battery cathode catalyst, FeCeNC exhibits excellent electrochemical performances, with an open-circuit voltage of 1.427 V, a maximum power density of 169.2 mW cm−2 and a stable cycling time of 80 h, demonstrating an excellent cycle performance.

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  • 3.
    Bi, Zenghui
    et al.
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhang, Hua
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhao, Xue
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wang, Yuwen
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Tan, Fang
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Chen, Songqing
    School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China.
    Feng, Ligang
    School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China.
    Zhou, Yingtang
    National Engineering Research Center for Marine Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China.
    Ma, Xin
    School of Energy and Chemical Engineering, Xinjiang Institute of Technology, Akesu, China.
    Su, Zhi
    School of Energy and Chemical Engineering, Xinjiang Institute of Technology, Akesu, China.
    Wang, Xinzhong
    School of Electronic Communication Technology, Shenzhen Institute of Information Technology, Shenzhen, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Highly dispersed La−O/N−C sites anchored in hierarchically porous nitrogen-doped carbon as bifunctional catalysts for high-performance rechargeable Zn−air batteries2023Ingår i: Energy Storage Materials, ISSN 2405-8289, E-ISSN 2405-8297, Vol. 54, s. 313-322Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inexpensive, high-activity bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are imperative for the development of energy storage and conversion systems. A nitrogen-doped carbon material with a micro−meso−macroporous structure doped with La (LaPNC) containing La−O/N−C active sites is prepared using SiO2 particle templating of carbon and a metal node exchange strategy. The coordination environment of La sites stabilized by two oxygen and four nitrogen atoms (LaO2N4), is further verified by X-ray absorption spectroscopy. The ORR half-wave potential reaches 0.852 V, and the OER overpotential reaches 263 mV at 10 mA cm−2. The Zn−air battery, with LaPNC as the air cathode, has a maximum power density of 202 mW cm−2 and achieves stable charge−discharge for at least 100 h without a significant increase or decrease in the charge or discharge voltages, respectively. Density functional theory calculations suggest that LaO2N4 sites exhibit the lowest activation free energy and the most easily desorbed oxygen capacity. This study provides new insights into the design of efficient, durable bifunctional catalysts as alternatives to precious-metal-based catalysts.

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  • 4.
    Fan, Xiaoyu
    et al.
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    Li, Rui
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Chen, Yafei
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Zhang, Shuai
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Liu, Tao
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Shao, Xiaodong
    State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials, Tubular Goods Research Institute, Xi'an, China.
    Wang, Shuhao
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Yue, Qiaoli
    School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng, China.
    Paper test strip for silver ions detection in drinking water samples based on combined fluorometric and colorimetric methods2023Ingår i: Arabian Journal of Chemistry, ISSN 1878-5352, E-ISSN 1878-5379 , Vol. 16, nr 2, artikel-id 104492Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, a portable silver ion (Ag+) sensor was fabricated based on a dual signal output system using black phosphorus quantum dots (BPQDs) as probes. It is the first work for Ag+ detection using paper test strip based on BPQDs. The color change of BPQDs paper sensor for the determination of Ag+ was easily identified by naked eye. BPQDs were synthesized from bulk black phosphorus (BP) by mechanical exfoliation combined with a solvothermal method. BPQDs exhibited blue fluorescence with a quantum yield of 8.82 %. The fluorescence of BPQDs can be quenched by Ag+, and the absorbance of BPQDs is increased with increasing Ag+ concentration. The mechanism of the interaction between BPQDs and Ag+ involving fluorescence quenching and bonding was investigated by experimental and computational methods. The detection limit of Ag+ was 1.56 μg/mL and 0.19 μg/mL using fluorometry and colorimetry methods, respectively. A portable visual sensor based on paper test strip was constructed for Ag+ detection using the colorimetric approach. The strategy was employed to determine Ag+ successfully in drinking water samples. Therefore, the proposed portable Ag+ sensor can be potentially utilized for the lab-free analysis of drinking water and even dietary samples.

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  • 5. Gao, Sanshuang
    et al.
    Liu, Jing
    Luo, Jun
    Mamat, Xamxikamar
    Sambasivam, Sangaraju
    Li, Yongtao
    Hu, Xun
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, China.
    Selective voltammetric determination of Cd(II) by using N,S-codoped porous carbon nanofibers2018Ingår i: Microchimica Acta, ISSN 0026-3672, E-ISSN 1436-5073, Vol. 185, artikel-id 282Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Porous carbon nanofibers codoped with nitrogen and sulfur (NFs) were prepared by pyrolysis of trithiocyanuric acid, silica nanospheres and polyacrylonitrile (PAN) followed by electrospinning. The NFs were used to modify a glassy carbon electrode (GCE) which then displayed highly sensitive response to traces of Cd(II). Compared to a bare GCE and a Nafion modified GCE, the GCE modified with codoped NFs shows improved sensitivity for Cd(II) in differential pulse anodic sweep voltammetry. The stripping peak current (typically measured at 0.81 V vs. Ag/AgCl) increases linearly in the 2.0–500 μg·L−1 Cd(II) concentration range. This is attributed to the large surface area (109 m2·g−1), porous structure, and high fraction of heteroatoms (19 at.% of N and 0.75 at.% of S). The method was applied to the determination of Cd(II) in (spiked) tap water where it gave recoveries that ranged between 96% and 103%.

  • 6. Gao, Sanshuang
    et al.
    Xu, Chuyang
    Yalikun, Nuerbiya
    Mamat, Xamxikamar
    Li, Yongtao
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Xun
    Liu, Jing
    Luo, Jun
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Science, Urumqi 830011, People's Republic of China.
    Sensitive and Selective Differential Pulse Voltammetry Detection of Cd(II) and Pb(II) Using Nitrogen-Doped Porous Carbon Nanofiber Film Electrode2017Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, nr 13, s. H967-H974Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon matrix materials are regarded as one of the most important electrode materials for heavy metal detection. But even so, optimization procedures of carbon nanofibers (CNFs) for tracing Cd(II) and Pb(II) remains challenging. Here, zeolitic imidazolate framework (ZIF-8)/polyacrylonitrile (PAN)-derived nitrogen-doped porous carbon nanofibers (N-PCNFs) were investigated as a new electrode material for determining the concentration of Cd(II) and Pb(II). By optimizing electrochemical conditions such as deposition potential, deposition time, pH of buffer solution, and quantity of N-PCNFs loaded on a glassy carbon electrode (GCE), the linear response curves of Cd(II) and Pb(II) could be obtained. Due to the unique structural feature and N content, the N-PCNFs possess excellent detection limits of 0.8 mu g L-1 for Cd(II) and 0.3 mu g L-1 for Pb(II) (S/N = 3). To manifest the practical use of the sensor platform the concentration of Cd(II) and Pb(II) in normal tap and waste water were monitored. According to the ICP-MS results, the calculated recovery (97.0-107%) indicates that N-PCNFs have potential as a candidate material to monitor the concentration of Cd(II) and Pb(II) in practical samples.

  • 7.
    Geng, Longlong
    et al.
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    An, Su
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Wang, Xiaoli
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Liu, Zhongmin
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Zhang, Xiuling
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Zhang, Da-Shuai
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Zhang, Yong-Zheng
    Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou, China.
    Wågberg, Thomas
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China.
    Valence-mixed CuOx-nanoparticles anchored biomass-based carbon nanofiber for boosting toxic nitroarenes reduction: Synthesis, kinetics, and mechanisms2022Ingår i: Journal of Environmental Chemical Engineering, E-ISSN 2213-3437, Vol. 10, nr 6, artikel-id 108689Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The rational modulation of metal catalysts with tailorable valence and redox properties is a promising strategy for further improving their catalytic performance. Herein, an environment-friendly grafting and thermal strategy was adopted to immobilize copper oxides nanoparticles on carbon nanofiber (CuOx/CF). Benefiting from the defect-rich surface and valence-mixed composition of the CuOx species, the optimized sample CuOx/CF-3 exhibits superb activity for the catalytic reduction of toxic nitrophenols. The complete conversion took only 1 min and an outstanding rate constant (k) of 112.7 × 10-3 s-1 was achieved under mild conditions (25 °C and 1 atm). Kinetic and recycle experiments demonstrated that the whole catalytic process obeys a pseudo-order kinetic, and the catalyst could maintain high conversion even after 13 successive recycles. These results demonstrate that CuOx/CF-3 is an alternative catalyst to noble metals, providing superb catalytic efficiency and stability in the reduction of toxic nitrophenols, and it can be expanded to develop other noble-metal-free catalysts for various applications.

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  • 8.
    Gracia-Espino, Eduardo
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Understanding the Interface of Six-Shell Cuboctahedral and Icosahedral Palladium Clusters on Reduced Graphene Oxide: Experimental and Theoretical Study2014Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, nr 18, s. 6626-6633Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Studies on noble-metal-decorated carbon nanostructures are reported almost on a daily basis, but detailed studies on the nanoscale interactions for well-defined systems are very rare. Here we report a study of reduced graphene oxide (rGOx) homogeneously decorated with palladium (Pd) nanoclusters with well-defined shape and size (2.3 +/- 0.3 nm). The rGOx was modified with benzyl mercaptan (BnSH) to improve the interaction with Pd clusters, and N,N-dimethylformamide was used as solvent and capping agent during the decoration process. The resulting Pd nanoparticles anchored to the rGOx-surface exhibit high crystallinity and are fully consistent with six-shell cuboctahedral and icosahedral clusters containing similar to 600 Pd atoms, where 45% of these are located at the surface. According to X-ray photoelectron spectroscopy analysis, the Pd clusters exhibit an oxidized surface forming a PdOx shell. Given the well-defined experimental system, as verified by electron microscopy data and theoretical simulations, we performed ab initio simulations using 10 functionalized graphenes (with vacancies or pyridine, amine, hydroxyl, carboxyl, or epoxy groups) to understand the adsorption process of BnSH, their further role in the Pd cluster formation, and the electronic properties of the graphene-nanoparticle hybrid system. Both the experimental and theoretical results suggest that Pd clusters interact with fiinctionalized graphene by a sulfur bridge while the remaining Pd surface is oxidized. Our study is of significant importance for all work related to anchoring of nanoparticles on nanocarbon-based supports, which are used in a variety of applications.

  • 9. Han, Xin-Bao
    et al.
    Tang, Xing-Yan
    Lin, Yue
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Liu, San-Gui
    Liang, Hai-Wei
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.
    Zhao, Xin-Jing
    Liao, Hong-Gang
    Tan, Yuan-Zhi
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Xie, Su-Yuan
    Zheng, Lan-Sun
    Ultrasmall Abundant Metal-Based Clusters as Oxygen-Evolving Catalysts2019Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 141, nr 1, s. 232-239Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The oxygen evolution reaction is a crucial step in water electrolysis to develop clean and renewable energy. Although noble metal-based catalysts have demonstrated high activity for the oxygen evolution reaction, their application is limited by their high cost and low availability. Here we report the use of a molecule-to-cluster strategy for preparing ultrasmall trimetallic clusters by using the polyoxometalate molecule as a precursor. Ultrafine (0.8 nm) transition-metal clusters with controllable chemical composition are obtained. The transition-metal clusters enable highly efficient oxygen evolution through water electrolysis in alkaline media, manifested by an overpotential of 192 mV at 10 mA cm–2, a low Tafel slope of 36 mV dec–1, and long-term stability for 30 h of electrolysis. We note, however, that besides the excellent performance as an oxygen evolution catalyst, our molecule-to-cluster strategy provides a means to achieve well-defined transition-metal clusters in the subnanometer regime, which potentially can have an impact on several other applications.

  • 10.
    He, Yingnan
    et al.
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    Huang, Yimin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Li, Wenyan
    Joint Institute for Environmental Research and Education, College of Resources and Environment, South China Agricultural University, Guangzhou, China.
    Li, Yongtao
    Joint Institute for Environmental Research and Education, College of Resources and Environment, South China Agricultural University, Guangzhou, China.
    Chang, Fengqin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhang, Hucai
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Separable amino-functionalized biochar/alginate beads for efficient removal of Cr(VI) from original electroplating wastewater at room temperature2022Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 373, artikel-id 133790Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An alginate gel bead composite adsorbent with polyethyleneimine (PEI) as a surface modifier and Eichhornia crassipes (EC) biochar, known as EC-alg/PEI-3, was added internally to the adsorb Cr(VI) from an aqueous environment. The functionalized gel beads were characterized using SEM, XPS, FTIR, and other techniques. The maximum adsorption capacities of EC-alg/PEI-3 were 714.3 mg g−1 at 10 °C and 769.2 mg g−1 at 25 °C. In the treatment of highly concentrated electroplating wastewater, EC-alg/PEI-3 can be dosed at 1.4 g L−1 to reduce the concentration of Cr(VI) to below 0.05 ppm. EC-alg/PEI-3 maintained a competitive adsorption capacity after six cycles. This spherical adsorbent material is easy to prepare, has a very high adsorption capacity, is environmentally friendly, and can be easily recycled. The EC-alg/PEI-3 gel beads are promising for the treatment of industrial wastewater.

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  • 11.
    He, Yingnan
    et al.
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Jia, Xiuxiu
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Zhang, Shusheng
    College of Chemistry, Zhengzhou University, Zhengzhou, China.
    Li, Xiaohua
    Rural Energy & Environment Agency, Ministry of Agriculture and Rural Affairs, Beijing, China.
    Huang, Yimin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Separatable MoS2 loaded biochar/CaCO3/Alginate gel beads for selective and efficient removal of Pb(II) from aqueous solution2022Ingår i: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 303, artikel-id 122212Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Centimeter-scale composite biochar-alginate gel beads (MoS2B/CaCO3/Alg) were designed for the adsorption of Pb(II) in water using MoS2 modified biochar as the filler, alginate as the matrix, and CaCO3 as the active additive component. The composite gel beads were characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and other techniques. MoS2B/CaCO3/Alg showed excellent adsorption capacity over a wide range of pH 4–7. The maximum adsorption capacities obtained using the Langmuir model were 769.2, 833.3, and 909.1 mg g−1 at 10, 25 and 40 °C, respectively. At a dosing rate of 0.4 g L−1, MoS2B/CaCO3/Alg was able to reduce the Pb(II) concentration to below 0.05 ppm in complex simulated lead battery wastewater. After 10 repeated cycles, MoS2B/CaCO3/Alg maintained a high removal rate of 98.4 %. This spherical adsorbent is simple to prepare and easy to recover, has an ultra-high adsorption capacity, and is mechanically stable and resistant to interference, thus it is expected to be suitable for application in industrial wastewater treatment.

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  • 12.
    He, Zhuang
    et al.
    School of Electronic Communication Technology, Shenzhen Institute of Information Technology, Shenzhen, China; School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, China.
    Zhang, Yunqiu
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Niu, Jianrui
    School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, China.
    Li, Zaixing
    School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, China.
    Wang, Xinzhong
    School of Electronic Communication Technology, Shenzhen Institute of Information Technology, Shenzhen, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Microwave-assisted synthesis of amorphous cobalt nanoparticle decorated N-doped biochar for highly efficient degradation of sulfamethazine via peroxymonosulfate activation2022Ingår i: Journal of Water Process Engineering, E-ISSN 2214-7144, Vol. 50, artikel-id 103226Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present work, a microwave-assisted and secondary roasting preparation process was used to synthesize nanocomposite materials. These materials were modified with amorphous cobalt nanoparticles (Co NPs) on the surface of biochar doped with different nitrogen sources (melamine (Me), 1,10-phenanthroline (Ph), and urea (Ur)). The nanocomposite (Co-N-C(Ur)) with urea as the nitrogen source promoted the generation of mesopores on the surface of carbon materials due to its evaporation during the preparation process thus enhancing the attachment sites of cobalt nanoparticles. The Co-N-C(Ur) had a more significant degradation effect on the primary carcinogen sulfamethazine (SMT) by activating peroxymonosulfate (PMS). The degradation rate of SMT pollutants was 96.6 % within 30 min. The optimal reaction conditions were as follows: catalyst dosage of 0.4 g L−1, PMS dosage of 0.812 mM, SMT concentration of 10 mg L−1, and pH of 5.67. Additionally, the Co-N-C(Ur) catalysts possess excellent specific surface area due to the evaporation effect of the calcination process of urea itself compared to other nitrogen source doping. Electrochemical tests revealed that the composites prepared with urea as the nitrogen source had higher PMS-induced current density and lowered material impedance values, which effectively promoted the catalytic performance of SMT degradation. Concurrently, the Co-N-C (Ur) + PMS reaction system exhibited excellent catalytic performance against other antibiotic organic pollutants. Subsequently, through the capture experiments and electron paramagnetic resonance technical analyses, it was determined that the singlet 1O2 played a leading role in the reaction system. Finally, a thorough liquid chromatography-mass spectrometry analysis suggested the possible SMT degradation pathways, thereby providing a new strategy for the subsequent heterogeneous catalysts to degrade persistent organic pollutants.

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  • 13.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Laboratory of Environmental Science and Technology, The Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sandström, Robin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Cheng, Shaodong
    Shen, Hangjia
    Wang, Chuanyi
    Guo, Shaojun
    Yang, Guang
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Atomistic understanding of the origin of high oxygen reduction electrocatalytic activity of cuboctahedral Pt3Co-Pt core-shell nanoparticles2016Ingår i: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 6, nr 5, s. 1393-1401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PtM-based core-shell nanoparticles are a new class of active and stable nanocatalysts for promoting oxygen reduction reaction (ORR); however, the understanding of their high electrocatalytic performance for ORR at the atomistic level is still a great challenge. Herein, we report the synthesis of highly ordered and homogeneous truncated cuboctahedral Pt3Co-Pt core-shell nanoparticles (cs-Pt3Co). By combining atomic resolution electron microscopy, X-ray photoelectron spectroscopy, extensive first-principles calculations, and many other characterization techniques, we conclude that the cs-Pt3Co nanoparticles are composed of a complete or nearly complete Pt monolayer skin, followed by a secondary shell containing 5-6 layers with similar to 78 at% of Pt, in a Pt3Co configuration, and finally a Co-rich core with 64 at% of Pt. Only this particular structure is consistent with the very high electrocatalytic activity of cs-Pt3Co nanoparticles for ORR, which is about 6 times higher than commercial 30%-Pt/Vulcan and 5 times more active than non-faceted (spherical) alloy Pt3Co nanoparticles. Our study gives an important insight into the atomistic design and understanding of advanced bimetallic nanoparticles for ORR catalysis and other important industrial catalytic applications.

  • 14.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Mikolajczuk, Ania
    Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland.
    Tai, Cheuk-Wai
    Stockholm Univ, Arrhenius Lab, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Borodzinski, Andrzej
    Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Palladium nanocrystals supported on helical carbon nanofibers for highly efficient electro-oxidation of formic acid, methanol and ethanol in alkaline electrolytes2012Ingår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 209, s. 236-242Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present the synthesis of palladium nanocrystals self-assembled on helical carbon nanofibers functionalized with benzyl mercaptan (Pd-S-HCNFs) and their electrocatalytic activity toward the oxidation of formic acid, methanol and ethanol. Helical carbon nanofibers (HCNFs) were first functionalized with benzyl mercaptan based on the pi-pi interactions between phenyl rings and the graphitic surface of HCNFs. Palladium nano crystals (PdNC) were fixed on the surface of functionalized HCNF by Pd-S bonds in a simple self-assembly method. The as-prepared materials were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV), and fuel cell tests. CV characterization of the as-prepared materials shows a very high electrocatalytic activity for oxidation of formic acid, ethanol and methanol in strong alkaline electrolyte. In comparison to commercial catalyst Vulcan XC-72 decorated with Pd nanoparticles, the proposed Pd-S-HCNFs nano composite material shows oxidation currents for formic acid, ethanol and methanol at the Pd-S-HCNF-modified electrode that are higher than that at the Pd/XC-72 modified electrode with a factor of 2.0, 1.5, and 2.3, respectively. In a formic acid fuel cell the Pd-S-HCNF modified electrode yields equal power density as commercial Pd/XC-72 catalyst. Our results show that Pd-decorated helical carbon nanofibers with diameters around 40-60 nm have very high potential as active material in fuel cells, electrocatalysts and sensors. (C) 2012 Elsevier B.V All rights reserved.

  • 15.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Ma, Jingyuan
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Jia, Xueen
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Lu, Lu
    Ma, Chuansheng
    Yang, Guang
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Small palladium islands embedded in palladium-tungsten bimetallic nanoparticles form catalytic hotspots for oxygen reduction2014Ingår i: Nature Communications, E-ISSN 2041-1723, Vol. 5, s. Article number: 5253-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The sluggish kinetics of the oxygen reduction reaction at the cathode side of proton exchange membrane fuel cells is one major technical challenge for realizing sustainable solutions for the transportation sector. Finding efficient yet cheap electrocatalysts to speed up this reaction therefore motivates researchers all over the world. Here we demonstrate an efficient synthesis of palladium-tungsten bimetallic nanoparticles supported on ordered mesoporous carbon. Despite a very low percentage of noble metal (palladium: tungsten = 1:8), the hybrid catalyst material exhibits a performance equal to commercial 60% platinum/Vulcan for the oxygen reduction process. The high catalytic efficiency is explained by the formation of small palladium islands embedded at the surface of the palladium-tungsten bimetallic nanoparticles, generating catalytic hotspots. The palladium islands are similar to 1 nm in diameter, and contain 10-20 palladium atoms that are segregated at the surface. Our results may provide insight into the formation, stabilization and performance of bimetallic nanoparticles for catalytic reactions.

  • 16.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Chalmers University of Technology.
    Jia, Xueen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Reduction free room temperature synthesis of a durable and efficient Pd/ordered mesoporous carbon composite electrocatalyst for alkaline direct alcohols fuel cell2014Ingår i: RSC Advances, E-ISSN 2046-2069, Vol. 4, nr 2, s. 676-682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of easy and environmentally benign synthesis methods of efficient electrocatalysts for use in energy conversion applications motivates researchers all over the world. Here we report a novel and versatile method to synthesize well-dispersed palladium-functionalized ordered mesoporous carbons (Pd/OMCs) at room temperature without any reducing agent by one-pot mixing of tri(dibenzylideneacetone)palladium(0) (Pd2DBA3) and OMCs together in a common N,N-dimethylformamide (DMF) solution. The formation of Pd nanoparticles and their crystallization on the OMC is catalyzed by protons in the solution and can thus be controlled by the solution pH. The complete process and the as-prepared nanocomposite was characterized by UV-spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (HTEM), X-ray photoelectron spectrum (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The electrocatalytic property of the as-decorated material was examined with cyclic voltammetry (CV). The Pd/OMC composite shows up to two times higher electrocatalytic ability with a significantly better durability towards ethanol and methanol oxidation in alkaline media compared to commercial high surface area conductive carbon black Vulcan XC-72 decorated with equivalent Pd nanoparticles. Our described method provides new insight for the development of highly efficient carbon based nanocatalysts by simple and environmentally sound methods.

  • 17.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Self-assembled palladium nanocrystals on helical carbon nanofibers as enhanced electrocatalysts for electro-oxidation of small molecules2012Ingår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, nr 17, s. 8541-8548Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a novel approach to prepare helical carbon nanofibers homogeneously functionalized with single crystal palladium nanoparticles via a phase-transfer method. The materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA) and electrochemical measurements. We find that homogeneous and small single-crystal Pd nanoparticles can be easily functionalized with phenyl mercaptan, transferred into the toluene phase from the dimethyl sulfoxide (DMSO) phase and then non-covalently self-assembled onto the surface of helical carbon nanofibers with a very good dispersion and homogeneous diameters of 4.5 +/- 0.6 nm. The palladium-helical carbon nanofiber composite exhibits significantly higher electrochemical active area and electrocatalytic activity towards the electrooxidation of formic acid, ethanol and methanol than the commercial electrocatalyst Pd/Vulcan XC-72. Our results show that the prepared material can be potentially used as an advanced nano-electrocatalyst in a direct alkaline fuel cell system.

  • 18.
    Hu, Guangzhi
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Tai, Cheuk-Wai
    Stockholm Univ, Dept Mat & Environm Chem, Stockholm, Sweden.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Phase-transfer synthesis of amorphous palladium nanoparticle-functionalized 3D helical carbon nanofibers and its highly catalytic performance towards hydrazine oxidation2012Ingår i: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 543, s. 96-100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Amorphous palladium nanoparticles functionalized helical carbon nanofibers (ApPd-HCNFs) were synthesized using a phase-transfer method. Palladium nanoparticles (Pd-NP) were first prepared using n-dodecyl sulfide as reducing agent and stabilizing ligands in ethanol. The Pd-NPs were then modified with benzyl mercaptan and transferred into a toluene solution with HCNFs which were decorated with amorphous palladium. The materials were characterized with high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and cyclic voltammetry showing that amorphous palladium nanoparticles were uniformly anchored at the HCNFs surface and that the ApPd-HCNFs exhibit high electrocatalytic activity towards hydrazine oxidation. (C) 2012 Elsevier B.V. All rights reserved.

  • 19.
    Huang, Ruihua
    et al.
    College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Zhu, Yeling
    College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China.
    Zhu, Jian
    College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Three-dimensional porous high boron-nitrogen-doped carbon for the ultrasensitive electrochemical detection of trace heavy metals in food samples2023Ingår i: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 442, artikel-id 130020Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Exposure to even trace amounts of Cd(II) and Pb(II) in food can have serious effects on the human body. Therefore, the development of novel electrochemical sensors that can accurately detect the different toxicity levels of heavy metal ions in food is of great significance. Based on the principle of green chemistry, we propose a new type of boron and nitrogen co-doped carbon (BCN) material derived from a metal-organic framework material and study its synthesis, characterization, and heavy-metal ion detection ability. Under the optimum conditions, the BCN-modified glassy carbon electrode was studied using square-wave anodic stripping voltammetry, which showed good electrochemical responses to Cd(II) and Pb(II), with sensitivities as low as 0.459 and 0.509 μA/μM cm2, respectively. The sensor was successfully used to detect Cd(II) and Pb(II) in Beta vulgaris var. cicla L samples, which is consistent with the results obtained using inductively coupled plasma-mass spectrometry. It also has a strong selectivity for complex samples. This study provides a novel approach for the detection of heavy metal ions in food and greatly expands the application of heteroatom-doped metal-free carbon materials in detection platforms.

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  • 20.
    Huang, Ruihua
    et al.
    Yunnan Tobacco Quality Supervision and Test Station, Kunming, China; College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China.
    Zhang, Ke
    Yunnan Tobacco Quality Supervision and Test Station, Kunming, China.
    Sun, Haowei
    Yunnan Tobacco Quality Supervision and Test Station, Kunming, China.
    Zhang, Dafeng
    School of Materials Science and Engineering, Liaocheng University, Liaocheng, China.
    Zhu, Jian
    College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Li, Wenyan
    College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
    Li, Yongtao
    College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
    Wang, Chunqiong
    Yunnan Tobacco Quality Supervision and Test Station, Kunming, China.
    Jia, Xiuxiu
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Star-shaped porous nitrogen-doped metal-organic framework carbon as an electrochemical platform for sensitive determination of Cd(II) in environmental and tobacco samples2022Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 1228, artikel-id 340309Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, cetyltrimethylammonium bromide and zeolitic imidazolate framework-8 (ZIF-8) were first assembled via the chemical co-precipitation, and high-quality carbon-based metal-free nanomaterials were synthesized using a heat-treatment process. The internal and morphological characteristics of hexagonal Star ZIF-8 were investigated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical sensor with a good response to Cd(II) was prepared via square-wave anodic stripping voltammetry (SWASV) with Star ZIF-8 nanomaterial-modified glassy carbon electrodes. The main parameters were adjusted to obtain the optimal stripping response and a wide linear range. Concurrently, under the calculation of SWASV, the sensitivity of Star ZIF-8-Nafion/GCE to Cd(II) was increased by five orders of magnitude (0.5–230 μg/L), and the determination level was even low to 0.48 μg/L. Based on the high anti-interference ability and stability of the sensor, the application potential of Star ZIF-8 carbon-based metal-free nanomaterials for the detection of trace Cd(II) in was confirmed.

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  • 21.
    Huang, Yimin
    et al.
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wang, Bing
    College of Resources and Environmental Engineering, Guizhou University, Guizhou, Guiyang, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    He, Yingnan
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhang, Hucai
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Li, Wenyan
    Joint Institute for Environmental Research and Education, College of resources and environment, South China Agricultural University, Guangzhou, China.
    Li, Yongtao
    Joint Institute for Environmental Research and Education, College of resources and environment, South China Agricultural University, Guangzhou, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Facile synthesis of sodium lignosulfonate/polyethyleneimine/sodium alginate beads with ultra-high adsorption capacity for Cr(VI) removal from water2022Ingår i: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 436, artikel-id 129270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chromium (VI) is a widely occurring toxic heavy metal ion in industrial wastewater that seriously impacts the environment. In this study, we used environmentally friendly sodium lignosulfonate (SL), polyethyleneimine (PEI), and sodium alginate (SA) to synthesize SL/PEI/SA beads by employing a simple crosslinking method with to develop a novel absorbent with excellent adsorption capacity and practical application in wastewater treatment. We studied the adsorption performance of SL/PEI/SA through batch adsorption and continuous dynamic adsorption experiments. SL/PEI/SA has ultra-high adsorption capacity (2500 mg·g-1) at 25 ℃, which is much higher than that of existing adsorbents. Humic acids and coexisting anions commonly found in wastewater have minimal effect on the adsorption performance of SL/PEI/SA. In the column system, 1 g SL/PEI/SA can treat 8.1 L secondary electroplating wastewater at a flow rate of 0.5 mLmin-1, thereby enabling the concentration of Cr(VI) in secondary electroplating wastewater to meet the discharge standard (< 0.2 mg·L-1). It is worth noting that the concentration of competitive ions in secondary electroplating wastewater is more than 500 times higher than that of Cr(VI). These results demonstrate that the novel SL/PEI/SA beads can be effectively applied in the removal of Cr(VI) in wastewater.

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  • 22.
    Jia, Xueen
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sharifi, Tiva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Tai, Cheuk-Wai
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Synthesis of Palladium/Helical Carbon Nanofiber Hybrid Nanostructures and Their Application for Hydrogen Peroxide and Glucose Detection2013Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 5, nr 22, s. 12017-12022Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on a novel sensing platform for H2O2 and glucose based on immobilization of palladium-helical carbon nanofiber (Pd-HCNF) hybrid nanostnictures and glucose oxidase (GOx) with Nafion on a glassy carbon electrode (GCE). HCNFs were synthesized by a chemical vapor deposition process on a C-60-supported Pd catalyst. Pd-HCNF nanocomposites were prepared by a one-step reduction free method in dimethylformamide (DMF). The prepared materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. The Nafion/Pd-HCNF/GCE sensor exhibits excellent electrocatalytic sensitivity toward H2O2 (315 mA M-1 cm(-2)) as probed by cyclic voltammetry (CV) and chronoamperometry. We show that Pd-HCNF-modified electrodes significantly reduce the overpotential and enhance the electron transfer rate. A linear range from 5.0 mu M to 2.1 mM with a detection limit of 3.0 mu M (based on the S/N = 3) and good reproducibility were obtained. Furthermore, a sensing platform for glucose was prepared by immobilizing the Pd-HCNFs and glucose oxidase (GOx) with Nafion on a glassy carbon electrode. The resulting biosensor exhibits a good response to glucose with a wide linear range (0.06-6.0 mM) with a detection limit of 0.03 mM and a sensitivity of 13 mA M-1 cm(-2). We show that small size and homogeneous distribution of the Pd nanoparticles in combination with good conductivity and large surface area of the HCNFs lead to a H2O2 and glucose sensing platform that performs in the top range of the herein reported sensor platforms.

  • 23. Jiang, Linhai
    et al.
    Yao, Mingguang
    Liu, Bo
    Li, Quanjun
    Liu, Ran
    Lv, Hang
    Lu, Shuangchen
    Gong, Chen
    Zou, Bo
    Cui, Tian
    Liu, Bingbing
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Controlled Synthesis of CeO2/Graphene Nanocomposites with Highly Enhanced Optical and Catalytic Properties2012Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, nr 21, s. 11741-11745Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, CeO2 nanocubes with the (200)-terminated surface/graphene sheet composites have been prepared successfully by a simple hydrothermal method. It is found that the CeO2 nanocubes with high crystallinity and specific exposed surface are well dispersed on well-exfoliated graphene surface. The (200)-terminated surface/graphene sheet composites modified electrode showed much higher sensitivity and excellent selectivity in its catalytic performance compared to a CeO2 nanoparticle-modified electrode. The photoluminescence intensity of the CeO2 anchored on graphene is about 30 times higher than that of pristine CeO2 crystals in air. The higher oxygen vacancy concentration in CeO2 is supposed to be an important cause for the higher photoluminescence and better electrochemical catalytic performance observed in the (200)-terminated surface/graphene sheet composites. Such ingenious design of supported well-dispersed catalysts in nanostructured ceria catalysts, synthesized in one step with an exposed high-activity surface, is important for technical applications and theoretical investigations.

  • 24. Jiang, Ruyuan
    et al.
    Liu, Niantao
    Su, Yuhong
    Gao, Sanshuang
    Mamat, Xamxikamar
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Li, Yongtao
    Hu, Xun
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Chinese Acad Sci, Xinjiang Tech Inst Phys & Chem, State Key Lab Basis Xinjiang Indigenous Med Plant, Key Lab Chem Plant Resources Arid Reg, Urumqi 830011, Peoples R China.
    Polysulfide/Graphene Nanocomposite Film for Simultaneous Electrochemical Determination of Cadmium and Lead Ions2018Ingår i: NANO, ISSN 1793-2920, Vol. 13, nr 8, artikel-id 1850090Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An integrative electroanalytical method was developed for detecting Cd2+ and Pb2+ ions in aqueous solutions. Polysulfide/graphene (RGO-S) nanocomposites were prepared and their performance as electrochemical sensors for Cd2+ and Pb2+ was evaluated. The RGO-S nanocomposite was carefully characterized by scanning electron microscopy with energy-dispersive X-ray spectrometry, transmission electron microscopy, and X-ray photoelectron spectroscopy. The as-prepared RGO-S was incorporated into a pyrolytic graphite electrode (RGO-S/PGE) and used for detecting trace amount of Cd2+ and Pb2+ by differential pulse anodic stripping voltammetry. Under optimal conditions, the stripping peak current of RGO-S/PGE varies linearly with heavy metal ion concentration in the ranges 2.0-300 mu g L-1 for Cd2+ and 1.0-300 mu g L-1 for Pb2+. The limits of detection for Cd2+ and Pb2+ were estimated to be about 0.67 mu g L-1 and 0.17 mu g L-1, respectively. The prepared electrochemical heavy-metal-detecting electrode provides good repeatability and reproducibility with high sensitivity, making it a suitable candidate for monitoring Cd2+ and Pb2+ concentrations in aqueous environmental samples.

  • 25.
    Klechikov, Alexey
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Sun, Jinhua
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Zheng, Mingbo
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Talyzin, Alexandr V.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Graphene decorated with metal nanoparticles: Hydrogen sorption and related artefacts2017Ingår i: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 250, s. 27-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hydrogen sorption by reduced graphene oxides (r-GO) is not found to increase after decoration with Pd and Pt nanoparticles. Treatments of metal decorated samples using annealing under hydrogen or air were tested as a method to create additional pores by effects of r-GO etching around nanoparticles. Increase of Specific Surface Area (SSA) was observed for some air annealed r-GO samples. However, the same treatments applied to activated r-GO samples with microporous nature and higher surface area result in breakup of structure and dramatic decrease of SSA. Our experiments have not revealed effects which could be attributed to spillover in hydrogen sorption on Pd or Pt decorated graphene. However, we report irreversible chemisorption of hydrogen for some samples which can be mistakenly assigned to spillover if the experiments are incomplete.

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  • 26.
    Li, Luhan
    et al.
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Zhang, Lei
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Nie, Zhicheng
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Ma, Wenyu
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Li, Nianpeng
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Yunnan, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Yunnan, Kunming, China.
    Tailoring charge reconfiguration in dodecahedral Co2P@carbon nanohybrids by triple-doping engineering for promoted reversible oxygen catalysis2022Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, nr 40, s. 21659-21671Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Simultaneously tuning the electronic structure of active sites and the microenvironment of the carbon matrix in metal phosphide/carbon nanohybrids is the most effective way to design and develop bi-functional electrocatalysts for electrochemically related energy storage devices. Inspired by this, a robust and advanced N/P co-doped carbon-based dodecahedron catalyst with confined Fe-doped Co2P particles was successfully prepared through a multi-doping engineering strategy. Phytic acid molecules, which were used in the synthesis of the catalyst, not only contribute to the formation of the porous structure, but also act as a phosphorus source to form the corresponding metal phosphide and the P dopant in the carbon matrix. Thanks to the unique composition and structure-dependent merits, the microenvironment of the electrocatalyst was significantly modulated, thus promoting the advantageous local charge rearrangement and smooth mass/charge transfer processes during the oxygen-related electrocatalytic reactions. As a result, the resultant catalyst exhibited significantly enhanced reversible oxygen activity, as evidenced by an ultra-small potential gap of 0.655 V (half-wave potential of 0.895 V for the oxygen reduction reaction; η10 of 320 mV for the oxygen evolution reaction), a remarkable specific capacity of 762 mA h gZn−1, and high voltaic efficiency, exceeding most previous reports. This study provides a new synthetic approach for fabricating highly efficient bi-functional oxygen catalysts and can be handily extended to the synthesis of other heterogeneous electrocatalysts for sustainable energy storage.

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  • 27.
    Li, Qian
    et al.
    State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China.
    Chen, Yuying
    State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China.
    Gao, Hui
    State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China.
    Li, Zeyu
    State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China.
    Qiu, Daiyu
    State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    In situ analysis of volatile oil in Angelica sinensis roots by fluorescence imaging combined with mass spectrometry imaging2023Ingår i: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 255, artikel-id 124253Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the spatial distribution and accumulation dynamics of volatile oil in Angelica sinensis roots was realized by fluorescence imaging combined with mass spectrometry imaging. The laser scanning confocal microscopy was used to determine the optimal excitation wavelength and the fluorescent stability of volatile oil in the sections of Angelica sinensis roots. The results demonstrated that 488 nm was the most suitable excitation wavelength for the identification and quantitative analysis of volatile oil. It was observed that volatile oil accumulated in the oil chamber of the phelloderm and secondary phloem, and the oil canal of the secondary xylem. The results also indicated that there were differences in content during different periods. Furthermore, the MALDI-TOF-MSI technology was used to study the spatial distribution and compare the chemical compositions of different parts of Angelica sinensis roots during the harvest period. A total of 55, 49, 50 and 30 compounds were identified from the head, body, tail of the root and root bark, respectively. The spatial distribution of phthalides, organic acids and other compounds were revealed in Angelica sinensis roots. The method developed in this study could be used for the in situ analysis of volatile oil in Angelica sinensis roots.

  • 28.
    Li, Xue
    et al.
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhao, Xue
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China; College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China.
    Lv, Jiapei
    State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
    Jia, Xiuxiu
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Huang, Yimin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Chang, Fengqin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Zhang, Hucai
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Self-supported porous copper oxide nanosheet arrays for efficient and selective electrochemical conversion of nitrate ions to nitrogen gas2023Ingår i: Journal of Materials Science & Technology, ISSN 1005-0302, Vol. 137, s. 104-111Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electrochemical techniques have shown advantages for the removal of low-concentration nitrate. Here, copper oxide nanosheets were grown on self-supporting nickel foam (NF) to prepare electrodes (CuO/NF), which realized the rapid and highly selective conversion of nitrate pollutants in sewage into nontoxic and harmless N2. The CuO/NF afforded 100% NO3– removal within 100 min and 99.53% selectivity for N2 at –50 mA without producing a lot of by-products (NO2–, NH4+, and N2H4). Furthermore, 81.8% of NO3– was removed under the given conditions after six experimental repetitions. These results suggest that the catalyst has excellent electrochemical stability. The performance of CuO/NF for the electrocatalytic removal of NO3– in simulated wastewater (which contained Cl– and SO42–) was almost unaffected. Because of the high efficiency, high stability, and low cost of CuO/NF, this catalyst is practical for the removal of nitrate for wastewater purification.

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  • 29.
    Li, Ziyao
    et al.
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Chen, Mengshan
    National Engineering Research Center for Marine Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhejiang 316004, Zhoushan, China.
    Zhang, Lei
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Xing, Rui
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Hu, Jinsong
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Huang, Xinhua
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Zhou, Chunhui
    School of Materials Science and Engineering, State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Anhui, Huainan, China.
    Zhou, Yingtang
    National Engineering Research Center for Marine Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhejiang 316004, Zhoushan, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Yunnan, Kunming, China.
    Atomic-level orbital coupling in a tri-metal alloy site enables highly efficient reversible oxygen electrocatalysis2023Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, nr 5, s. 2155-2167Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Complex multi-metallic alloys with ultra-small sizes have received extensive attention in the fields of Zn-air battery and water splitting, because of their unique advantages including adjustable composition, tailorable active sites, and optimizable electronic structure. In this effort, an atomic-level orbital coupling strategy is presented to effectively regulate the electronic structures of ultra-small tri-metal Fe-Co-Ni nanoalloy particles confined in an N-doped carbon hollow nanobox. As expected, the optimal nanoalloy hybrid material exhibited notable bi-functional catalytic performances toward the oxygen reduction reaction (half-wave potential of 0.902 V) and oxygen evolution reaction (1.589 V at 10 mA cm−2) with a small ΔE of 0.687 V, exceeding the precious-metal-based and many previously reported catalysts. Furthermore, the as-assembled Zn-air device also displayed a superior specific capacity of 894 mA h g−1, a maximal power density of 247 mW cm−2, and impressive durability (over 100 hours). Ultraviolet photoelectron spectroscopy and density functional theory calculations revealed that the electronic structures could be finely tuned and optimized through ternary metal alloying, resulting in a suitable d-band center and advantageous interfacial charge-transfer, which in turn could effectively reduce the involved energy barriers in the electrocatalytic process and significantly boost its intrinsic activity of reversible oxygen catalysis. Thus, this work affords an effective method for the rational creation of bi-functional non-noble-metal-based electrocatalysts for sustainable energy technology.

  • 30. Liu, Niantao
    et al.
    Mamat, Xamxikamar
    Jiang, Ruyuan
    Tong, Wei
    Huang, Yudai
    Jia, Dianzeng
    Li, Yongtao
    Wang, Lei
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.
    Facile high-voltage sputtering synthesis of three-dimensional hierarchical porous nitrogen-doped carbon coated Si composite for high performance lithium-ion batteries2018Ingår i: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 343, s. 78-85Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Various kinds of efforts have been devoted to ameliorate the serious volume-expansion effect and low electron conductivity of silicon-based materials in lithium ion batteries. Here, we report a facile high voltage sputtering process to prepare three-dimensional hierarchical porous nitrogen-doped carbon coated Si microsphere to significantly improve the lithium storage performance. The structure and morphology of the as-obtained samples are characterized by X-ray diffraction, transmission electron microscope and scanning electron microscope. The results indicate that the as-prepared composite is composed of silicon nanoparticles (similar to 100 nm) coated with conductive thin carbon layer (similar to 8.5 nm). The composite shows excellent lithium storage performance with a reversible capacity of 1565 mAh g(-1) after 100 cycles at a current density of 0.5 A g(-1), as well as a long cycling performance at the high current density of 2 A g(-1). The facile preparation process and highly silicon-loading (similar to 78%) makes the prepared material be a great potential application in lithium-ion batteries.

  • 31.
    Ma, Xin
    et al.
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Guo, Qin
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Zhang, Jingmei
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Su, Zhi
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Zhou, Shuxing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Wei, Longyang
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Li, Shouzhu
    Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China.
    Yue, Fan
    Key Laboratory of Oil & Gas Fine Chemicals Ministry of Education, Xinjiang University, Xinjiang, Urumqi, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Laboratory of Nanofiber Membrane Materials and Devices, Xinjiang Institute of Technology, Akesu, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    [CH3NH3][M(HCOO)3]-based 2D porous NiCo2S4 nanosheets for high-performance supercapacitors with high power densities2022Ingår i: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 437, artikel-id 135337Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cost-effective and high-performance electrode materials for energy storage and conversion are essential for commercial applications. In this work, the influence of solvent on the morphologies of [CH3NH3][M(HCOO)3] precursors was studied to design and synthesize two-dimensional (2D) porous NiCo2S4 nanosheets with different structures. As an electrode material for supercapacitors, Microflower-NiCo2S4 exhibits excellent capacitance (1,141 F g−1 at 1 A g−1) and stability (88.2% of initial capacitance maintained after 5,000 cycles at 5 A g−1). Moreover, an asymmetric capacitor was constructed using Microflower-NiCo2S4 and porous carbon (PC) and demonstrated an energy density of 51.25 Wh kg−1 at a power density of 397.5 W kg−1. When two Microflower-NiCo2S4//PC asymmetric supercapacitors were assembled in series, the device supplied power for an alarm clock with dimensions of 6.1 × 6.1 cm2 for more than 32 min. Therefore, the preparation of metal sulfides and metal oxides with hollow structures using a [CH3NH3][M(HCOO)3]-template has potential applications in energy storage and conversion.

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  • 32.
    Ma, Yu-Bo
    et al.
    School of Chemical Engineering, Chongqing Chemical Industry Vocational College, Chongqing, China.
    Wang, Yu-Wen
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, Yunnan University, Kunming, China.
    Zhang, Da-Feng
    School of Materials Science and Engineering, Liaocheng University, Liaocheng, China.
    Jia, Xiu-Xiu
    School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, Yunnan University, Kunming, China.
    Wang, Yin
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Zhou, Shu-Xing
    Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guang-Zhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. School of Materials and Energy, Institute for Ecological Research and Pollution Control of Plateau Lakes, Yunnan University, Kunming, China.
    One-pot synthesis of Pd-Au-alloy-nanoparticle-decorated graphene oxide functionalized with dodecahydrododecaborate cluster for rapid and complete reduction of 4-nitrophenol at room temperature2023Ingår i: Rare Metals, ISSN 1001-0521, E-ISSN 1867-7185, Vol. 42, nr 11, s. 3622-3629Artikel i tidskrift (Refereegranskat)
  • 33.
    Nitze, Florian
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Mazurkiewicz, Marta
    Malolepszy, Artur
    Mikolajczuk, Anna
    Kedzierzawski, Piotr
    Tai, Cheuk-Wai
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Kurzydlowski, Krzysztof Jan
    Stobinski, Leszek
    Borodzinski, Andrzej
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Synthesis of palladium nanoparticles decorated helical carbon nanofiber as highly active anodic catalyst for direct formic acid fuel cells2012Ingår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 63, s. 323-328Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a single metal approach to produce highly active catalyst materials based on Pd-decorated helical carbon nanofibers. Helical carbon fibers are synthesized by a chemical vapor deposition process on a C-60 supported Pd catalyst and the obtained fibers are functionalized by H2O2 followed by a decoration with Pd nanoparticles. Although transmission electron microscopy images show that the decoration is relatively inhomogeneous the electrocatalytic activity for formic acid oxidation is very high. Cyclic voltammetry measurements (CV) show that the generated current peak value for Pd-decorated helical carbon nanofibers is 300 mA/mg(Pd) for a scan rate of 10 mV/s. This is significantly higher than the corresponding value of a reference sample of multiwalled carbon nanotubes decorated with Pd nanoparticles by the same process. Fuel cell tests for our Pd-decorated helical carbon nanofibers also displayed a high power density, although not as superior to Pd-decorated multiwalled nanotubes as measured by CV. Our results show that helical carbon nanofibers have several good properties, such as a rigid anchoring of catalyst nanoparticles and a suitable structure for creating functionalization defects which make them an interesting candidate for electrochemical applications. (C) 2012 Elsevier Ltd. All rights reserved.

  • 34.
    Nitze, Florian
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Department of Chemical and Biological Engineering, Chalmers University of Technology, Sweden.
    Sandström, Robin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Mazurkiewicz, Marta
    Malolepszy, Artur
    Stobinski, Leszek
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Direct support mixture painting, using Pd(0) organo-metallic compounds - an easy and environmentally sound approach to combine decoration and electrode preparation for fuel cells2014Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, nr 48, s. 20973-20979Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An inventive, fast and straight-forward approach for the direct preparation of fuel cell electrodes has been developed and tested. Our approach avoids long catalyst preparation and post-synthesis treatment. It reduces the use of chemicals and thereby concomitantly lowers the environmental impact and improves cost efficiency. It combines decoration of the support by palladium nanoparticles with electrode preparation through a simple one-step ink-painting and annealing process. Composites have been investigated by high resolution transmission electron microscopy, scanning electron microscopy, and Xray diffraction. Crystalline particles are well-attached and well-distributed on the support. Particles are of few nanometers in size and spherical for decorated Vulcan whereas they are larger and irregularly shaped for decorated helical carbon nanofibers (HCNFs). Electrodes with a metal loading of 0.8 mg cm(-2) have been tested in a direct formic acid fuel cell. Both the Vulcan and the HCNF electrodes show a similar and high power output of up to 120 mW mg(-1). They also show similar performances in deactivation experiments conducted at 200 mA cm(-2) even when using only high purity grade formic acid. After deactivation the electrodes show no structural damage, making them superior to most commercial catalysts. The electrodes can be completely regenerated to initial activity by simple treatment with water. The easy regeneration process indicates that CO-adsorption on the fuel cell anode catalyst is not the main poisoning mechanism responsible for electrode degeneration.

  • 35.
    Peng, Yan
    et al.
    College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, China.
    Li, Meng
    College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, China; College of Chemistry, Zhengzhou University, Zhengzhou, China.
    Jia, Xiuxiu
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Su, Jianru
    College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, China.
    Zhao, Xue
    College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China.
    Zhang, Shusheng
    College of Chemistry, Zhengzhou University, Zhengzhou, China.
    Zhang, Haibo
    College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China.
    Zhou, Xiaohai
    College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China.
    Chen, Jianbing
    Research Academy of Non-metallic Mining Industry Development, Materials and Environmental Engineering College, Chizhou University, Chizhou, China.
    Huang, Yimin
    Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Cu Nanoparticle-Decorated Boron-Carbon-Nitrogen Nanosheets for Electrochemical Determination of Chloramphenicol2022Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 14, nr 25, s. 28956-28964Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present work, irregular Cu nanoparticle-decorated boron-carbon-nitrogen (Cu-BCN) nanosheets were successfully synthesized. A Cu-BCN dispersion was deposited on a bare glassy carbon electrode (GCE) to prepare an electrochemical sensor (Cu-BCN/GCE) for the detection of chloramphenicol (CAP) in the environment. Cu-BCN was characterized using high-resolution scanning transmission electron microscopy (HRSTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and X-ray photoelectron spectroscopy (XPS). The performance of the Cu-BCN/GCE was studied using electrochemical impedance spectroscopy (EIS), and its advantages were proven by electrode comparison. Differential pulse voltammetry (DPV) was used to optimize the experimental conditions, including the amount of Cu-BCN deposited, enrichment potential, deposition time, and pH of the electrolyte. A linear relationship between the CAP concentration and current response was obtained under the optimized experimental conditions, with a wide linear range and a limit of detection (LOD) of 2.41 nmol/L. Cu-BCN/GCE exhibited high stability, reproducibility, and repeatability. In the presence of various organic and inorganic species, the influence of the Cu-BCN-based sensor on the current response of CAP was less than 5%. Notably, the prepared sensor exhibited excellent performance in real-water samples, with satisfactory recovery.

  • 36.
    Perivoliotis, Dimitrios K.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Ekspong, Joakim
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Zhao, Xue
    College of Chemistry and Engineering, Yunnan Normal University, Kunming, China.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Recent progress on defect-rich electrocatalysts for hydrogen and oxygen evolution reactions2023Ingår i: Nano Today, ISSN 1748-0132, E-ISSN 1878-044X, Vol. 50, artikel-id 101883Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    To meet the demanding requirements for clean energy production, the need to develop advanced electrocatalysts for efficiently catalysing the water splitting reactions attracts a continuously increased attention. However, to meet the anticipated expansion in green hydrogen production from renewable energy sources, the catalysts used for the water splitting reaction not only need to satisfy the required figures of merit but should concurrently be based mainly on abundant, non-critical materials with low environmental impact. In last decades, non-noble metal catalysts, based on transition metals, rare-earth metals, dichalcogenides, and light elements such as phosphorus, nitrogen, and sulphur have shown improved performance. Moreover, in recent years increased interest has been focused on variations of such materials, more specifically on the introduction of defects to further boost their catalytic performance. Through the many studies performed over the last years, it is now possible to summarize, understand and describe the role of these defects for the water splitting reactions, namely the hydrogen and oxygen evolution reactions, and thereby to suggest strategies in the development of next generation electrocatalysts. This is the goal of the current review; we critically summarize the latest progress on the role of introduced defects for catalytic electrolysis applications by scrutinizing the structure–performance correlation as well as the specific catalytic activity. A broad class of nanomaterials is covered, comprising transition metal dichalcogenides, transition metal oxides and carbides, carbon-based materials as well as metal–organic frameworks (MOFs). Finally, the main challenges and future strategies and perspectives in this rapidly evolving field are provided at the end of the review.

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  • 37. Qiao, Mengfei
    et al.
    Wang, Ying
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Mamat, Xamxikamar
    Hu, Xun
    Zou, Guoan
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, and Key Laboratory of Plant Resources and Chemistry in Arid Regions, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Xinjiang, China.
    Ni-Co bimetallic coordination effect for long lifetime rechargeable Zn-air battery2020Ingår i: Journal of Energy Challenges and Mechanics, E-ISSN 2056-9386, Vol. 47, s. 146-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of bifunctional oxygen electrocatalysts with high efficiency, high stability, and low cost is of great significance to the industrialization of rechargeable Zn–air batteries. A widely accepted view is that the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) follow different catalytic mechanisms, and accordingly they need different active sites for catalysis. Transition metal elements have admirable electronic acceptance ability for coordinating with reactants, and this can weaken the bond energy between reactants, thus promoting the ORR or OER reactions. Herein, the ORR and OER activities of different transition metal supported nitrogen-doped carbon nanotubes were systematically studied and compared. The optimal catalyst for synchronous ORR and OER was obtained by pyrolyzing melamine, cobalt nitrate, and nickel nitrate on carbon nanotubes, called cobalt–nickel supported nitrogen-mixed carbon nanotubes (CoNi–NCNT), which were equipped with two types of high-performance active sites—the Co/Ni–N–C structure for the ORR and CoNi alloy particles for the OER—simultaneously. Remarkably, the optimized CoNi–NCNT exhibited a satisfactory bifunctional catalytic activity for both the ORR and OER. The value of the oxygen electrode activity parameter, ΔE, of CoNi–NCNT was 0.81 V, which surpasses that of catalysts Pt/C and Ir/C, and most of the non-precious metal-based bifunctional electrocatalysts reported in previous literatures. Furthermore, a specially assembled rechargeable Zn–air cell with CoNi–NCNT loaded carbon paper as an air cathode was used to evaluate the practicability. As a result, a superior specific capacity of 744.3 mAh/gZn, a peak power density of 88 mW/cm2, and an excellent rechargeable cycling stability were observed, and these endow the CoNi–NCNT with promising prospects for practical application.

  • 38. Qin, Danfeng
    et al.
    Gao, Shanshuang
    Wang, Le
    Shen, Hangjia
    Yalikun, Nuerbiya
    Sukhrobov, Parviz
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Zhao, Yujie
    Mamat, Xamxikamar
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang indigenous medicinal plants resource utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Science, Urumqi, China.
    Three-dimensional carbon nanofiber derived from bacterial cellulose for use in a Nafion matrix on a glassy carbon electrode for simultaneous voltammetric determination of trace levels of Cd(II) and Pb(II)2017Ingår i: Microchimica Acta, ISSN 0026-3672, E-ISSN 1436-5073, Vol. 184, nr 8, s. 2759-2766Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The authors describe the preparation of carbon nanofibers (CNFs) with a three-dimensional network structure by one-step carbonization of bacterial cellulose at 800 degrees C. The 3D CNFs wrapped with Nafion polymer were cast on a glassy carbon electrode (GCE) which then enables sensitive detection of Cd(II) and Pb(II). Under optimized conditions and at typical stripping peaks of around -0.80 and -0.55 V (vs Ag/AgCl), the electrode exhibits high sensitivity and a wide analytical range of 2-100 mu g.L-1 for both Cd(II) and Pb(II). The detection limits are 0.38 mu g.L-1 for Cd(II) and 0.33 mu g.L-1 for Pb(II), respectively. The modified GCE was successfully employed to the determination of trace amounts of Cd(II) and Pb(II) in both tap water and waste water.

  • 39. Qin, Danfeng
    et al.
    Hu, Xun
    Dong, Yemin
    Mamat, Xamxikamar
    Li, Yongtao
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    An Electrochemical Sensor Based on Green gamma-AlOOH-Carbonated Bacterial Cellulose Hybrids for Simultaneous Determination Trace Levels of Cd(II) and Pb(II) in Drinking Water2018Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, nr 7, s. B328-B334Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An eco-friendly gamma-AlOOH-carbonated bacterial cellulose (gamma-AlOOH-CBC) hybrids material was fabricated by simple pyrolysis and hydrothermal treatments. The obtained hybrids possess an intrinsic 3D nanofibrous structure decorated with chaff-like gamma-AlOOH particles. Owing to the good adsorption property and conductive, gamma-AlOOH-CBC hybrids were used to modified the glass carbon electrode (GCE) for simultaneous determination of Cd(II) and Pb(II) in aqueous samples by differential pulse anodic stripping voltammetry (DPASV) method. Various parameters affected Cd(II) and Pb(II) measurement were optimized. Under the optimal conditions, the limit of detection (S/N = 3) of the gamma-AlOOH-CBC modified electrode was evaluated to be 0.17 mu g.L-1 for Cd(II) and 0.10 mu g.L-1 for Pb(II) with the linear range of the calibration curves ranged 0.5-250 mu g.L-1 for Cd(II) and Pb(II). Furthermore, the developed electrode was also successfully utilized for monitoring trace Cd(II) and Pb(II) in drinking water samples with satisfactory results.

  • 40. Qin, Danfeng
    et al.
    Wang, Le
    Gao, Sanshuang
    Wang, Ying
    Mamat, Xamxikamar
    Li, Yongtao
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Cheng, Hao
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in AridRegions, State Key Laboratory Basis of Xinjiang indigenousmedicinal plants resource utilization, Xinjiang Technical In-stitute of Physics and Chemistry, Chinese Academy of Science,Urumqi 830011, China.
    N-Doped Hollow Porous Carbon Spheres/Bismuth Hybrid Film Modified Electrodes for Sensitive Voltammetric Determination of Trace Cadmium2018Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 30, nr 9, s. 1906-1912Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, N-doped hollow porous carbon spheres (N-HPCSs) were synthesized by silicon dioxide template-assisted polybenzoxazine (PB) coating strategy. The prepared N-HPCSs have a smooth hollow ball structure surrounded by a well-defined porous shell. Combining with in-situ plating of Bi film, the N-HPCSs were further fabricated a sensitive electrochemical platform for determination trace levels of Cd(II) by differential pulse anodic stripping voltammetry (DPASV). Under the optimized conditions, the Bi-N-HPCSs based sensor displays a linear response to Cd(II) over the range of 0.5gL(-1) to 150gL(-1). Meanwhile, the limit of detection (LOD, S/N=3) is estimated to be around 0.16gL(-1) for Cd(II), which is 31 times lower than the safety values set by United States Environmental Protection Agency (EPA) for the drinking water. Moreover, the proposed method was successfully applied to detection of Cd(II) in tap water and lake water, and the analytical results of the presented method are agreed well with inductively coupled plasma-mass spectrometry (ICP-MS) data. Due to the excellent analytical performance, the fabricated electrode is promised for future development in monitoring of cadmium pollution in the environment.

  • 41.
    Sandström, Robin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, China.
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Ma, Jingyuan
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Yttria stabilized and surface activated platinum (PtxYOy) nanoparticles through rapid microwave assisted synthesis for oxygen reduction reaction2018Ingår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 46, s. 141-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The enhancement of platinum (Pt) based catalysts for the oxygen reduction reaction (ORR) by addition of rare earth metals represents a promising strategy to achieve high activity yet low content of the precious metal and concurrently addresses stability issues experienced by traditional late transition metal doping. Improvement in Pt utilization is essential for vehicular applications where material cost and abundancy is a great concern. Here we report a fast and efficient production route of yttria-stabilized platinum nanoparticles (PtxYOy) using a conventional household microwave oven. ORR performance showed a significant improvement and an optimum activity at a 3:1 Pt:Y ratio outperforming that of commercial Pt-Vulcan with a doubled specific activity. Incorporation of Y is evidenced by extended X-ray absorption fine structure and energy dispersive X-ray analysis, while significant amounts of integrated Y2O3 species are detected by X-ray photoelectron spectroscopy. Density functional theory calculations suggest surface migration and oxidation of Y, forming stable superficial yttrium oxide species with low negative enthalpies of formation. The robustness of PtxYOy is shown experimentally and through theoretical arguments demonstrating that surface yttria acts as a stabilizing agent and promoter of highly active ORR sites on the remaining Pt surface, surpassing even the Pt3Y alloy configuration.

  • 42.
    Sandström, Robin
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, China.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Compositional Evaluation of Coreduced Fe-Pt Metal Acetylacetonates as PEM Fuel Cell Cathode Catalyst2018Ingår i: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 1, nr 12, s. 7106-7115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Platinum iron nanoparticles were produced by solvothermal coreduction of organic Fe and Pt precursor compounds and supported on conventional Vulcan XC 72. Evaluation of oxygen reduction performance reveals a highly active surface with up to 5 times the specific activity of commercial Pt Vulcan measured in O-2-saturated 0.1 M HClO4. A particle size of 5.5 nm for the best performing sample, produced from an initial metal ratio of 1:1, provided 28% higher mass activity than the commercial reference. Membrane electrode assemblies, optimized for both H-2/O-2 and direct formic acid fuel cells, were produced, and the PEM fuel cell cathodic performance displayed results with similar enhancements as its ex situ measured mass activity, although a delamination of the catalyst layer from the membrane could be observed even when employing a hot-pressing procedure during MEA fabrication. Physical characterizations including X-ray photoelectron spectroscopy and in situ X-ray diffraction reveal oxidized states of Fe incorporated into the disordered face-centered cubic Pt nanoparticles, supported by composition-dependent morphological changes as observed by transmission electron microscopy. The provided insight into fuel cell performance as well as CO-oxidation attributes are expected to assist in selecting suitable applications and operating conditions for such FePt type nanoparticles.

  • 43.
    Sharifi, Tiva
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Barzegar, Hamid Reza
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Jia, Xueen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nitze, Florian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Nordblad, Per
    Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala, Sweden.
    Tai, Cheuk-Wai
    Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Formation of nitrogen-doped graphene nanoscrolls by adsorption of magnetic gamma-Fe2O3 nanoparticles2013Ingår i: Nature Communications, E-ISSN 2041-1723, Vol. 4, s. 2319-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Graphene nanoscrolls are Archimedean-type spirals formed by rolling single-layer graphene sheets. Their unique structure makes them conceptually interesting and understanding their formation gives important information on the manipulation and characteristics of various carbon nanostructures. Here we report a 100% efficient process to transform nitrogen-doped reduced graphene oxide sheets into homogeneous nanoscrolls by decoration with magnetic gamma-Fe2O3 nanoparticles. Through a large number of control experiments, magnetic characterization of the decorated nanoparticles, and ab initio calculations, we conclude that the rolling is initiated by the strong adsorption of maghemite nanoparticles at nitrogen defects in the graphene lattice and their mutual magnetic interaction. The nanoscroll formation is fully reversible and upon removal of the maghemite nanoparticles, the nanoscrolls return to open sheets. Besides supplying information on the rolling mechanism of graphene nanoscrolls, our results also provide important information on the stabilization of iron oxide nanoparticles.

  • 44.
    Sharifi, Tiva
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Chen, Anran
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Oxygen Reduction Reactions on Single- or Few-Atom Discrete Active Sites for Heterogeneous Catalysis2020Ingår i: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 10, nr 11, artikel-id 1902084Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The oxygen reduction reaction (ORR) is of great importance in energy-converting processes such as fuel cells and in metal-air batteries and is vital to facilitate the transition toward a nonfossil dependent society. The ORR has been associated with expensive noble metal catalysts that facilitate the O-2 adsorption, dissociation, and subsequent electron transfer. Single- or few-atom motifs based on earth-abundant transition metals, such as Fe, Co, and Mo, combined with nonmetallic elements, such as P, S, and N, embedded in a carbon-based matrix represent one of the most promising alternatives. Often these are referred to as single atom catalysts; however, the coordination number of the metal atom as well as the type and nearest neighbor configuration has a strong influence on the function of the active sites, and a more adequate term to describe them is metal-coordinated motifs. Despite intense research, their function and catalytic mechanism still puzzle researchers. They are not molecular systems with discrete energy states; neither can they fully be described by theories that are adapted for heterogeneous bulk catalysts. Here, recent results on single- and few-atom electrocatalyst motifs are reviewed with an emphasis on reports discussing the function and the mechanism of the active sites.

  • 45.
    Sharifi, Tiva
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Jia, Xueen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Formation of active sites for Oxygen reduction reactions by transformation of Nitrogen functionalities in Nitrogen-doped Carbon nanotubes2012Ingår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 6, nr 10, s. 8904-8912Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heat treating nitrogen-doped multiwalled carbon nanotubes containing up to six different types of nitrogen functionalities transforms particular nitrogen functionalities into other types which are more catalytically active toward oxygen reduction reactions (ORR). In the first stage, the unstable pyrrolic functionalities transform into pyridinic functionalities followed by an immediate transition into quaternary center and valley nitrogen functionalities. By measuring the electrocatalytic oxidation reduction current for the different samples, we achieve information on the catalytic activity connected to each type of nitrogen functionality. Through this, we conclude that quaternary nitrogen valley sites, N-Q(valley), are the most active sites for ORR in N-CNTs. The number of electrons transferred in the ORR is determined from ring disk electrode and rotating ring disk electrode measurements. Our measurements indicate that the ORR processes proceed by a direct four-electron pathway for the N-Q(valley) and the pyridinic sites while it proceeds by an indirect two-electron pathway via hydrogen peroxide at the N-Q(center) sites. Our study gives both insights on the mechanism of ORR on different nitrogen functionalities in nitrogen-doped carbon nanostructures and it proposes how to treat samples to maximize the catalytic efficiency of such samples.

  • 46. Shen, Hangjia
    et al.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Ma, Jingyuan
    Tang, Haodong
    Mamat, Xamxikamar
    Wagberg, Thomas
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.
    Guo, Shaojun
    Atomically FeN2 moieties dispersed on mesoporous carbon: A new atomic catalyst for efficient oxygen reduction catalysis2017Ingår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 35, s. 9-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Earth-abundant materials with Fe-N-C centers have been identified as promising catalysts for oxygen reduction reaction (ORR), but these alternatives for Pt catalysts are usually the porphyrin-like FeN4 configuration. The density functional theory (DFT) calculations reveal that FeN2 outperforms FeN4 due to its lower interaction with *O-2 and *OH intermediates and enhanced electron transport, however, achieving an optimum design of these earth-abundant materials with the enriched FeN2 catalytic centers is still a great challenge. Here, we report an intriguing template casting strategy to introduce a mass of atomically dispersed FeN2 moieties onto the surface of N-doped ordered mesoporous carbon for boosting ORR electrocatalysis. One of unique parts herein is to pre anchor Fe precursor on the surface of template (SBA-15) during catalyst synthesis, preventing Fe from penetrating into the carbon skeleton and facilitating the removal of excessive Fe-based particles during silica elimination by HF etching, resulting in a desirable model structure comprising only highly active atomically dispersed FeN2 sites, as confirmed by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), extended X-ray absorption fine structure (EXAFS) and Mossbauer spectroscopy analysis. The well-defined structure prompts us to understand the nature of the catalytic active sites, and to demonstrate that the catalyst activity is linearly proportional to the concentration of FeN2 sites. The obtained atomic electrocatalyst exhibits superior electrocatalytic performance for ORR with a more positive half-wave potential than that of Pt/C catalyst. We further establish a kinetic model to predict the ORR activity of these single-atom dispersed catalysts. The present work elaborates on a profound understanding for designing low-cost, highly efficient FeN2-based electrocatalyst for boosting ORR.

  • 47. Shen, Hangjia
    et al.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Ma, Jingyuan
    Zang, Ketao
    Luo, Jun
    Wang, Le
    Gao, Sanshuang
    Mamat, Xamxikamar
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions State Key Laboratory Basis of Xinjiang indigenous medicinal plants resource utilization Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of Sciences.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Guo, Shaojun
    Synergistic Effects between Atomically Dispersed Fe-N-C and C-S-C for the Oxygen Reduction Reaction in Acidic Media2017Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 56, nr 44, s. 13800-13804Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Various advanced catalysts based on sulfur-doped Fe/N/C materials have recently been designed for the oxygen reduction reaction (ORR); however, the enhanced activity is still controversial and usually attributed to differences in the surface area, improved conductivity, or uncertain synergistic effects. Herein, a sulfur-doped Fe/N/C catalyst (denoted as Fe/SNC) was obtained by a template-sacrificing method. The incorporated sulfur gives a thiophene-like structure (C-S-C), reduces the electron localization around the Fe centers, improves the interaction with oxygenated species, and therefore facilitates the complete 4e- ORR in acidic solution. Owing to these synergistic effects, the Fe/SNC catalyst exhibits much better ORR activity than the sulfur-free variant (Fe/NC) in 0.5m H2SO4.

  • 48. Shen, Hangjia
    et al.
    Gracia-Espino, Eduardo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Wang, Le
    Qin, Danfeng
    Gao, Sanshuang
    Mamat, Xamxikamar
    Ren, Wei
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Chinese Acad Sci, Xinjiang Tech Inst Phys & Chem, Urumqi 830011, Peoples R China.
    Microwave-assisted synthesis of multimetal oxygen-evolving catalysts2017Ingår i: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 81, s. 116-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Oxygen evolution reaction (OER) plays a pivotal role in water-splitting. Here, we report a facile method to synthesize multimetal supported on commercial carbon black via a time-saving microwave process. Crystalline FeNi3 nanoparticles homogeneously doped with Mo are formed via a microwave treatment and activated to metal oxyhydroxide in-situ during cyclic voltammetry test with overpotential of only 280 mV at 10 mA cm(-2) for OER in alkaline electrolyte, outperforming RuO2. Our synthesis methodology is a promising alternative for large-scale production, delivering a valuable contribution to catalyst preparation and electrocatalytic water oxidation research.

  • 49. Shen, Hangjia
    et al.
    Qin, Danfeng
    Li, Yuzhen
    Li, Shouzhu
    Yang, Chi
    Yuan, Qunhui
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    In situ magnesiothermal synthesis of mesoporous MgO/OMC composite for sensitive detection of lead ions2016Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 28, nr 12, s. 2939-2946Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mesoporous materials have exceptional properties for application owing to their ability to absorb and interact with guest species. A novel MgO/OMC composite with mesoporous structure was successfully synthesized via in situ magnesiothermic reduction. The structure was confirmed by N-2 sorption isotherms, X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). By using nafion and bismuth films as co-modifiers, the MgO/OMC composite material shows high sensitivity of 0.113 mu A.L mu g(-1) and lower background current for electrochemical determination of lead ion (Pb2+) by using anodic stripping voltammetry. The high specific surface area and good mass transfer on the proposed mesoporous material, as well as the outstanding adsorption abilities of MgO to metal ions and the excellent conductivity of the carbon skeleton contribute to the enhanced electrochemical response of Pb2+. As the stripping response of Bi/MgO/OMC-Nafion/PGE is highly linear (R-2 = 0.998) over a Pb2+ concentration range of 2 to 300 mg/L, it was successfully used to analyse Pb2+ in real tap-water samples with good recoveries.

  • 50. Sukhrobov, Parviz
    et al.
    Numonov, Sodik
    Gao, Sanshuang
    Mamat, Xamxikamar
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Guo, Yufen
    Liu, Liwei
    Hu, Guangzhi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous, Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, P. R. China.
    Nonenzymatic Glucose Biosensor Based on NiNPs/Nafion/Graphene Film for Direct Glucose Determination in Human Serum2018Ingår i: NANO, ISSN 1793-2920, Vol. 13, nr 7, artikel-id 1850075Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study describes a type of novel nickel nanoparticles (NiNPs) decorated on Nafiongraphene composite film by using the electrochemical deposition method. It was used to fabricate electrochemical biosensors for sensitive nonenzymatic glucose detection. Compared with the Nafion-graphene film and NiNPs-modified glassy carbon electrode (NiNPs-GCE), the NiNPs/Nafion/graphene/GCE showed the best electrocatalytic activity towards glucose oxidation in alkaline medium. The NiNPs/Nafion/graphene/GCE at an applied potential of +0.55 V in a linear range of 1-200 mu M presented a high sensitivity of 3437.25 mu A center dot mM(-1) cm(-2) with coefficient of correlation R-2 = 0.999; and in a linear range of 200-10800 mu M it performed the best sensitivity of 2848.6 mu A center dot mM(-1) cm(-2) with coefficient of correlation R-2 = 0.995 towards glucose oxidation. For a concentration up to 200 mu M, a linear range was obtained with a limit of detection of 0.6 mu M (signal to noise = 3) and as much as 10 800 mu M with a limit of detection of 0.82 mu M (signal to noise = 3). The time of responses was about 1-1.5 s with the addition of 0.1-1 mM glucose. In addition, NiNPs/Nafion/graphene/GCE also has a high anti-interference ability toward common oxidative interfering species, such as uric acid, ascorbic acid and dopamine. More importantly, NiNPs/Nafion/graphene/GCE was successfully used for the determination of glucose concentration in human serum samples in comparison with a local hospital. The NiNPs/Nafion/graphene/GCE exhibited high sensitivity, low working potential, good stability, excellent electrical properties, enhanced selectivity and fast amperometric responses to glucose oxidation. Thus, as a nonenzymatic sensor, it is promising for future glucose determination development.

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