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Publications (10 of 242) Show all publications
Hu, Q., Zhou, H., Ding, Y., Wågberg, T. & Han, X. (2024). Advances in bridging homogeneous and heterogeneous water oxidation catalysis by insolubilized polyoxometalate clusters. ACS Catalysis, 14(8), 5898-5910
Open this publication in new window or tab >>Advances in bridging homogeneous and heterogeneous water oxidation catalysis by insolubilized polyoxometalate clusters
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2024 (English)In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 14, no 8, p. 5898-5910Article, review/survey (Refereed) Published
Abstract [en]

The water oxidation half-reaction is vital in numerous alternative-energy blueprints and technologies since it can provide four protons and four electrons necessary for transforming renewable energy into chemicals and fuels. Significant progress has been made in recent decades in regard to the development of heterogeneous and homogeneous water oxidation catalysts (WOCs). However, homogeneous and heterogeneous catalysts are two parallel frontiers in catalysis science, each possessing their individual advantages and disadvantages. It is urgently required to construct desirable catalysts combining the merits and overcoming the natural shortcomings of homogeneous and heterogeneous WOCs. This Perspective demonstrates an overview of recent progress in utilizing insoluble polyoxometalate (POM) clusters as a promising bridge between homogeneous and heterogeneous WOCs and discusses the characterization methods for the stability, the origin of enhanced activities, electron transfer dynamics, and structure-property correlation of insoluble POM cluster WOCs. This Perspective not only guides the design of robust and efficient insoluble POM cluster catalysts applied for energy transformation but also provides important insights into the design of POM-based heterogeneous catalysts applied in other important fields.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
Keywords
bridge, heterogeneous catalysis, homogeneous catalysis, insoluble polyoxometalate clusters, water oxidation
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-223233 (URN)10.1021/acscatal.4c00201 (DOI)2-s2.0-85189543072 (Scopus ID)
Available from: 2024-04-19 Created: 2024-04-19 Last updated: 2024-04-19Bibliographically approved
Wang, T., Li, M., Gu, Z., Qu, C., Segervald, J., Salh, R., . . . Kou, W. (2024). Fluoride releasing in polymerblends of poly(ethylene oxide) and poly(methyl methacrylate). Frontiers in Chemistry, 12, Article ID 1356029.
Open this publication in new window or tab >>Fluoride releasing in polymerblends of poly(ethylene oxide) and poly(methyl methacrylate)
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2024 (English)In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 12, article id 1356029Article in journal (Refereed) Published
Abstract [en]

Introduction: Polymethyl methacrylate is a polymer commonly used in clinicaldentistry, including denture bases, occlusal splints and orthodontic retainers.

Methods: To augment the polymethyl methacrylate-based dental appliances incounteracting dental caries, we designed a polymer blend film composed ofpolymethyl methacrylate and polyethylene oxide by solution casting and addedsodium fluoride.

Results: Polyethylene oxide facilitated the dispersion of sodium fluoride,decreased the surface average roughness, and positively influenced thehydrophilicity of the films. The blend film made of polymethyl methacrylate,polyethylene oxide and NaF with a mass ratio of 10: 1: 0.3 showed sustainedrelease of fluoride ions and acceptable cytotoxicity. Antibacterial activity of all thefilms to Streptococcus mutans was negligible.

Discussion: This study demonstrated that the polymer blends of polyethyleneoxide and polymethyl methacrylate could realize the relatively steady release offluoride ions with high biocompatibility. This strategy has promising potential toendow dental appliances with anti-cariogenicity.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2024
Keywords
dental materials, polymethyl methacrylate, polyethylene oxide, fluoride ion release, polymer blend
National Category
Medical and Health Sciences Dentistry
Identifiers
urn:nbn:se:umu:diva-220718 (URN)10.3389/fchem.2024.1356029 (DOI)2-s2.0-85185521631 (Scopus ID)
Funder
Region Västerbotten, RV-937838The Kempe Foundations, JCSMK22-0122The Kempe Foundations, SMK-21-0015Swedish Research Council, 2021-04778Swedish Research Council, 2020-04437
Available from: 2024-02-09 Created: 2024-02-09 Last updated: 2024-02-29Bibliographically approved
Rafei, M., Piñeiro-García, A., Wu, X., Perivoliotis, D. K., Wågberg, T. & Gracia-Espino, E. (2024). Hydrogen evolution mediated by sulfur vacancies and substitutional Mn in few-layered molybdenum disulfide. Materials Today Energy, 41, Article ID 101524.
Open this publication in new window or tab >>Hydrogen evolution mediated by sulfur vacancies and substitutional Mn in few-layered molybdenum disulfide
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2024 (English)In: Materials Today Energy, ISSN 2468-6069, Vol. 41, article id 101524Article in journal (Refereed) Published
Abstract [en]

MoS2 is widely praised as a promising replacement for Pt as an electrocatalyst for the hydrogen evolution reaction (HER), but even today, it still suffers from low performance. This issue is tackled by using Mn3+ as a surface modifier to trigger sulfur vacancy formation and enhance electron transport in few-layered 2H MoS2. Only 10% of Mn is sufficient to transform the semiconductive MoS2 into an active HER electrocatalyst. The insertion of Mn reduces both HER onset potential and Tafel slope which allows reaching 100 mA/cm2 at an overpotential of 206 mV, ten times larger of what undoped MoS2 can achieve. The enhanced activity arises because Mn3+ introduces electronic states near the conduction band, promotes sulfur vacancies, and increases the hydrogen adsorption. In addition to its facile production and extended shelf-life, Mn–MoS2 exhibits an efficiency of 73% at 800 mA/cm2 and 2.0 V when used in proton exchange membrane water electrolyzers.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Hydrogen evolution reaction, Manganese, Proton exchange membrane, Sulfur vacancy, Water electrolysis
National Category
Materials Chemistry Other Physics Topics
Identifiers
urn:nbn:se:umu:diva-221781 (URN)10.1016/j.mtener.2024.101524 (DOI)2-s2.0-85185894201 (Scopus ID)
Funder
Swedish Research Council, 2018-03937The Kempe Foundations, JCK-2132The Kempe Foundations, JCK-2021Carl Tryggers foundation , CTS 21-1581Swedish Foundation for Strategic ResearchSwedish National Infrastructure for Computing (SNIC)
Available from: 2024-03-19 Created: 2024-03-19 Last updated: 2024-03-19Bibliographically approved
Nie, Z., Zhang, L., Zhu, Q., Ke, Z., Zhou, Y., Wågberg, T. & Hu, G. (2024). Reversed charge transfer induced by nickel in Fe-Ni/Mo2C@nitrogen-doped carbon nanobox for promoted reversible oxygen electrocatalysis. Journal of Energy Chemistry, 88, 202-212
Open this publication in new window or tab >>Reversed charge transfer induced by nickel in Fe-Ni/Mo2C@nitrogen-doped carbon nanobox for promoted reversible oxygen electrocatalysis
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2024 (English)In: Journal of Energy Chemistry, ISSN 2095-4956, E-ISSN 2096-885X, Vol. 88, p. 202-212Article in journal (Refereed) Published
Abstract [en]

The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities, influences the electronic structures of the supported metal, affects the adsorption energies of reaction intermediates, and ultimately impacts the catalytic performance. In this study, we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system. Specifically, electrons were transferred from the metal-based species to N-doped carbon, while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel. This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo2C@nitrogen-doped carbon catalyst, with a half-wave potential of 0.91 V towards oxygen reduction reaction (ORR) and a low overpotential of 290 mV at 10 mA cm−2 towards oxygen evolution reaction (OER) under alkaline conditions. Additionally, the Fe-Ni/Mo2C@carbon heterojunction catalyst demonstrated high specific capacity (794 mA h gZn−1) and excellent cycling stability (200 h) in a Zn-air battery. Theoretical calculations revealed that Mo2C effectively inhibited charge transfer from Fe to the support, while secondary doping of Ni induced a charge transfer reversal, resulting in electron accumulation in the Fe-Ni alloy region. This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process, enhancing the catalytic efficiency of both ORR and OER. Consequently, our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Charge transfer reversal, Metal-support interaction, Oxygen evolution reaction, Oxygen reduction reaction, Zinc-air battery
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:umu:diva-216642 (URN)10.1016/j.jechem.2023.09.009 (DOI)2-s2.0-85174079048 (Scopus ID)
Available from: 2023-11-29 Created: 2023-11-29 Last updated: 2023-11-29Bibliographically approved
Eriksson, A., Kawde, A., Hrachowina, L., McKibbin, S. R., Shi, Q., Borgström, M. T., . . . Uhlig, J. (2024). Synthesis of well-ordered functionalized silicon microwires using displacement talbot lithography for photocatalysis. ACS Omega, 9(18), 20623-20628
Open this publication in new window or tab >>Synthesis of well-ordered functionalized silicon microwires using displacement talbot lithography for photocatalysis
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2024 (English)In: ACS Omega, E-ISSN 2470-1343, Vol. 9, no 18, p. 20623-20628Article in journal (Refereed) Published
Abstract [en]

Metal-assisted chemical etching (MACE) is a cheap and scalable method that is commonly used to obtain silicon nano- or microwires but lacks spatial control. Herein, we present a synthesis method for producing vertical and highly periodic silicon microwires, using displacement Talbot lithography before wet etching with MACE. The functionalized periodic silicon microwires show 65% higher PEC performance and 2.3 mA/cm2 higher net photocurrent at 0 V compared to functionalized, randomly distributed microwires obtained by conventional MACE at the same potentials.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-224249 (URN)10.1021/acsomega.4c03039 (DOI)2-s2.0-85191880373 (Scopus ID)
Funder
The Kempe Foundations, JCK3140Swedish Research Council, 2020-04995Swedish Energy Agency, 50709-1Swedish Research Council, 2021-05207Swedish Research Council, 2021-04629
Available from: 2024-05-15 Created: 2024-05-15 Last updated: 2024-05-15Bibliographically approved
Zhang, H., Aierke, A., Zhou, Y., Ni, Z., Feng, L., Chen, A., . . . Hu, G. (2023). A high-performance transition-metal phosphide electrocatalyst for converting solar energy into hydrogen at 19.6% STH efficiency. Carbon Energy, 5(1), Article ID e217.
Open this publication in new window or tab >>A high-performance transition-metal phosphide electrocatalyst for converting solar energy into hydrogen at 19.6% STH efficiency
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2023 (English)In: Carbon Energy, E-ISSN 2637-9368, Vol. 5, no 1, article id e217Article in journal (Refereed) Published
Abstract [en]

The construction of high-efficiency and low-cost non-noble metal bifunctional electrocatalysts for water electrolysis is crucial for commercial large-scale application of hydrogen energy. Here, we report a novel strategy with erbium-doped NiCoP nanowire arrays in situ grown on conductive nickel foam (Er-NiCoP/NF). Significantly, the developed electrode shows exceptional bifunctional catalytic activity, which only requires overpotentials of 46 and 225 mV to afford a current density of 10 mA cm−2 for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. Density functional theory calculations reveal that the appropriate Er incorporation into the NiCoP lattice can significantly modulate the electronic structure with the d-band centers of Ni and Co atoms by shifting to lower energies with respect to the Fermi level, and optimize the Gibbs free energies of HER/OER intermediates, thereby accelerating water-splitting kinetics. When assembled as a solar-driven overall water-splitting electrolyzer, the as-prepared electrode shows a high and stable solar-to-hydrogen efficiency of 19.6%, indicating its potential for practical storage of intermittent energy.

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Keywords
bifunctional electrocatalysts, electronic regulation, hydrogen evolution reaction, oxygen evolution reaction, solar-to-hydrogen efficiency
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:umu:diva-213604 (URN)10.1002/cey2.217 (DOI)000807975000001 ()2-s2.0-85131573101 (Scopus ID)
Funder
Swedish Research Council
Available from: 2023-08-31 Created: 2023-08-31 Last updated: 2023-08-31Bibliographically approved
Hong, J., Zhang, L., Zhu, Q., Du, Z., Zhou, Y., Wågberg, T. & Hu, G. (2023). A macroporous carbon nanoframe for hosting Mott-Schottky Fe-Co/Mo2C sites as an outstanding bi-functional oxygen electrocatalyst. Materials Horizons, 10(12), 5969-5982
Open this publication in new window or tab >>A macroporous carbon nanoframe for hosting Mott-Schottky Fe-Co/Mo2C sites as an outstanding bi-functional oxygen electrocatalyst
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2023 (English)In: Materials Horizons, ISSN 2051-6347, E-ISSN 2051-6355, Vol. 10, no 12, p. 5969-5982Article in journal (Refereed) Published
Abstract [en]

Simultaneously optimizing the d-band center of the catalyst and the mass/charge transport processes during the oxygen catalytic reaction is an essential but arduous task in the pursuit of creating effective and long-lasting bifunctional oxygen catalysts. In this study, a Fe-Co/Mo2C@N-doped carbon macroporous nanoframe was successfully synthesized via a facile “conformal coating and coordination capture” pyrolysis strategy. As expected, the resulting heterogeneous electrocatalyst exhibited excellent reversible oxygen electrocatalytic performance in an alkaline medium, as demonstrated by the small potential gap of 0.635 V between the operating potential of 1.507 V at 10 mA cm−2 for the oxygen evolution reaction and the half-wave potential of 0.872 V towards the oxygen reduction reaction. Additionally, the developed Zn-air battery employing the macroporous nanoframe heterostructure displayed an impressive peak power density of 218 mW cm−2, a noteworthy specific capacity of 694 mA h gZn−1, and remarkable charging/discharging cycle durability. Theoretical calculations confirmed that the built-in electric field between the Fe-Co alloy and Mo2C semiconductor could induce advantageous charge transport and redistribution at the heterointerface, contributing to the optimization of the d-band center of the nanohybrid and ultimately leading to a reduction in the reaction energy barrier during catalytic processes. The exquisite macroporous nanoframe facilitated the rapid transport of ions and charges, as well as the smooth access of oxygen to the internal active site. Thus, the presented unique electronic structure regulation and macroporous structure design show promising potential for the development of robust bifunctional oxygen electrodes.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-216639 (URN)10.1039/d3mh01237a (DOI)001090565800001 ()37885433 (PubMedID)2-s2.0-85175609605 (Scopus ID)
Available from: 2023-11-16 Created: 2023-11-16 Last updated: 2023-12-12Bibliographically approved
Zäll, E., Järn, M., Karlsson, S., Tryggeson, H., Tuominen, M., Sundin, M. & Wågberg, T. (2023). Aerosol-based deposition of broadband antireflective silica coating with closed mesoporous structure. Solar Energy Materials and Solar Cells, 250, Article ID 112078.
Open this publication in new window or tab >>Aerosol-based deposition of broadband antireflective silica coating with closed mesoporous structure
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2023 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 250, article id 112078Article in journal (Refereed) Published
Abstract [en]

Solar energy will be a crucial part of the sustainable, fossil free energy production of the future. A majority of this will be produced by solar collectors and photovoltaics. Important for the efficient utilization of the incident solar energy for both technologies are a cover glass with antireflective coatings giving it a high solar transmittance. In the current paper we describe the development of antireflective mesoporous silica coatings on low-iron float glass using the aerosol-based nFOG™ deposition technique. The coatings exhibit a hexagonal and closed pore structure, high smoothness, superhydrophilic properties (contact angle <5°) and consistent thicknesses of approximately 110 nm. This is in line with optimal thickness determined from simulations of the antireflective behavior. Low-iron float glass coated on both sides show a highly reproducible solar weighted transmittance of 95% in the wavelength range 300–2500 nm and an antireflective effect increasing with incident angle. The smoothness, closed pores and low contact angle indicate a high cleanability, which in combination with the high transmittance render a competitive broadband antireflective coating well adapted for solar glass applications.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Aerosol-based deposition, Antireflective coating, Hexagonal mesoporous silica, nFOG™, Solar collector, Solar glass
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:umu:diva-201188 (URN)10.1016/j.solmat.2022.112078 (DOI)000884106800001 ()2-s2.0-85141234079 (Scopus ID)
Funder
Vinnova, 2018-02588Swedish Research Council, 2017-59504862Swedish Energy Agency, 45419-1Swedish Energy Agency, 52487-1
Available from: 2022-12-01 Created: 2022-12-01 Last updated: 2023-03-24Bibliographically approved
Hong, J., Chen, M., Zhang, L., Qin, L., Hu, J., Huang, X., . . . Hu, G. (2023). Asymmetrically coupled co single-atom and co nanoparticle in double-shelled carbon-based nanoreactor for enhanced reversible oxygen catalysis. Chemical Engineering Journal, 455, Article ID 140401.
Open this publication in new window or tab >>Asymmetrically coupled co single-atom and co nanoparticle in double-shelled carbon-based nanoreactor for enhanced reversible oxygen catalysis
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2023 (English)In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 455, article id 140401Article in journal (Refereed) Published
Abstract [en]

Simultaneous construction of size-asymmetric metal single atoms and nanoparticle active sites in advanced and robust carrier materials is particularly important yet challenging for efficient reversible oxygen catalysis. Herein, a facile “chemical etching/in-Situ capture” synthesis strategy was developed to fabricate a unique double-shelled carbon-based nanobox integrated with size-asymmetric Co single-atom (CoSA) and metallic Co nanoparticle (CoNP) moiety. As expected, this well-managed catalyst product yielded remarkable bifunctional electrocatalytic performances in alkaline electrolytes, with a decent half-wave potential of 0.886 V for oxygen reduction reaction (ORR) and a small overpotential of 341 mV at 10 mA/cm2 for oxygen evolution reaction (OER). Besides, this nanobox catalyst served as a cost-effective and efficient oxygen electrode in the assembled rechargeable ZABs, exceeding the mixed electrocatalyst of expensive Pt/C-RuO2, in terms of the elevated peak power density of 239 mW/cm2, the promoted specific capacity of 770 mAh/gZn, as well as the appreciable charge–discharge cycle stability. Theoretical calculations revealed that the strong interaction between the delicate CoSA site and CoNP phase, could effectively optimize the adsorption and desorption energy barriers of reaction intermediates on the designed catalyst surface, thus achieving synergistic enhancement of electrocatalytic activity towards ORR and OER. This finding affords a feasible and effective strategy to achieve highly active and durable bifunctional catalysts for both fundamental research and practical rechargeable ZABs applications.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Co nanoparticle, Co single-atom, Double-shelled nanobox, N-doped carbon, Reversible oxygen catalysis
National Category
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-201630 (URN)10.1016/j.cej.2022.140401 (DOI)000931200900001 ()2-s2.0-85143273244 (Scopus ID)
Funder
Swedish Research Council, 2017-04862Swedish Research Council, 2021-04629Swedish Energy Agency, 45419-1Swedish Foundation for Strategic Research, 2030-PUSH
Available from: 2022-12-14 Created: 2022-12-14 Last updated: 2023-06-19Bibliographically approved
Li, Z., Chen, M., Zhang, L., Xing, R., Hu, J., Huang, X., . . . Hu, G. (2023). Atomic-level orbital coupling in a tri-metal alloy site enables highly efficient reversible oxygen electrocatalysis. Journal of Materials Chemistry A, 11(5), 2155-2167
Open this publication in new window or tab >>Atomic-level orbital coupling in a tri-metal alloy site enables highly efficient reversible oxygen electrocatalysis
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2023 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 5, p. 2155-2167Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-203977 (URN)10.1039/d2ta08566f (DOI)000910536900001 ()2-s2.0-85146157789 (Scopus ID)
Funder
Swedish Research Council, 2017-04862Swedish Research Council, 2021-04629Swedish Energy Agency, 45419-1Swedish Foundation for Strategic Research, Agenda 2030-PUSH
Available from: 2023-01-24 Created: 2023-01-24 Last updated: 2023-09-21Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-5080-8273

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