umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Klechikov, Alexey
Alternative names
Publications (10 of 18) Show all publications
Iakunkov, A., Sun, J., Rebrikova, A., Korobov, M., Klechikov, A., Vorobiev, A., . . . Talyzin, A. V. (2019). Swelling of graphene oxide membranes in alcohols: effects of molecule size and air ageing.. Journal of Materials Chemistry A, 7, 11331-11337
Open this publication in new window or tab >>Swelling of graphene oxide membranes in alcohols: effects of molecule size and air ageing.
Show others...
2019 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, p. 11331-11337Article in journal (Refereed) Published
Abstract [en]

Swelling of Hummers graphene oxide (HGO) membranes in a set of progressively longer liquid alcohols (methanol to 1-nonanol) was studied using synchrotron radiation XRD after air ageing over prolonged periods of time. Both precursor graphite oxides and freshly prepared HGO membranes were found to swell in the whole set of nine liquid alcohols with an increase of interlayer spacing from ∼7 Å (solvent free) up to ∼26 Å (in 1-nonanol). A pronounced effect of ageing on swelling in alcohols was found for HGO membranes stored in air. The HGO membranes aged for 0.5–1.5 years show progressively slower swelling kinetics, a non-monotonic decrease of saturated swelling in some alcohols and complete disappearance of swelling for alcohol molecules larger than hexanol. Moreover, the HGO membranes stored under ambient conditions for 5 years showed a nearly complete absence of swelling in all alcohols but preserved swelling in water. In contrast, precursor graphite oxide powder showed unmodified swelling in alcohols even after 4 years of ageing. Since the swelling defines the size of permeation channels, the ageing effect is one of the important parameters which could explain the strong variation in reported filtration/separation properties of GO membranes. The time and conditions of air storage require standardization for better reproducibility of results related to performance of GO membranes in various applications. The ageing of GO membranes can be considered not only as a hindrance/degradation for certain applications, but also as a method to tune the swelling properties of HGO membranes for better selectivity in sorption of solvents and for achieving better selective permeability.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Materials Chemistry
Research subject
Physics
Identifiers
urn:nbn:se:umu:diva-160413 (URN)10.1039/C9TA01902B (DOI)000472225200050 ()
Funder
EU, Horizon 2020, 785219The Kempe Foundations
Available from: 2019-06-18 Created: 2019-06-18 Last updated: 2019-07-18Bibliographically approved
Sun, J., Klechikov, A., Moise, C., Prodana, M., Enachescu, M. & Talyzin, A. (2018). A Molecular Pillar Approach To Grow Vertical Covalent Organic Framework Nanosheets on Graphene: Hybrid Materials for Energy Storage. Angewandte Chemie International Edition, 57(4), 1034-1038
Open this publication in new window or tab >>A Molecular Pillar Approach To Grow Vertical Covalent Organic Framework Nanosheets on Graphene: Hybrid Materials for Energy Storage
Show others...
2018 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, no 4, p. 1034-1038Article in journal (Refereed) Published
Abstract [en]

Hybrid 2D–2D materials composed of perpendicularly oriented covalent organic frameworks (COFs) and graphene were prepared and tested for energy storage applications. Diboronic acid molecules covalently attached to graphene oxide (GO) were used as nucleation sites for directing vertical growth of COF-1 nanosheets (v-COF-GO). The hybrid material has a forest of COF-1 nanosheets with a thickness of 3 to 15 nm in edge-on orientation relative to GO. The reaction performed without molecular pillars resulted in uncontrollable growth of thick COF-1 platelets parallel to the surface of GO. The v-COF-GO was converted into a conductive carbon material preserving the nanostructure of precursor with ultrathin porous carbon nanosheets grafted to graphene in edge-on orientation. It was demonstrated as a high-performance electrode material for supercapacitors. The molecular pillar approach can be used for preparation of many other 2D-2D materials with control of their relative orientation.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
National Category
Condensed Matter Physics
Research subject
nanomaterials
Identifiers
urn:nbn:se:umu:diva-145739 (URN)10.1002/anie.201710502 (DOI)000428208700030 ()29210484 (PubMedID)
Available from: 2018-03-16 Created: 2018-03-16 Last updated: 2018-06-09Bibliographically approved
Sandström, R., Ekspong, J., Annamalai, A., Sharifi, T., Klechikov, A. & Wågberg, T. (2018). Fabrication of microporous layer - free hierarchical gas diffusion electrode as a low Pt-loading PEMFC cathode by direct growth of helical carbon nanofibers. RSC Advances, 8(72), 41566-41574
Open this publication in new window or tab >>Fabrication of microporous layer - free hierarchical gas diffusion electrode as a low Pt-loading PEMFC cathode by direct growth of helical carbon nanofibers
Show others...
2018 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, no 72, p. 41566-41574Article in journal (Refereed) Published
Abstract [en]

Improving interfacial contact between each component in the proton exchange membrane fuel cell (PEMFC) can lead to a significant increase in power density and Pt utilization. In this work, the junction between the catalyst layer and gas diffusion layer (GDL) is greatly enhanced through direct attachment of helical carbon nanofibers, giving rise to a hierarchical structure within the electrical interconnections. The alternative novel GDL is produced by spraying a thin layer of Pd2C60 precursor on commercial carbon paper, followed by chemical vapor deposition growth resulting in a surface morphology of well-attached nanofibers surrounding the microfibers present in the commercial carbon paper. Subsequent solvothermal deposition of platinum nanoparticles allowed evaluation of its suitability as gas diffusion electrode in cathodic H-2/O-2 PEMFC environment. A combination of lowered charge transfer resistance and enhanced Pt-utilization is attributed to its unique wire-like appearance and its robust properties. The fabricated microporous layer - free GDL is suitable for relatively aggressive membrane electrode assembly fabrication procedures and is produced by industrially favorable techniques, rendering it capable of efficiently supporting small amounts of precious metal catalyst nanoparticles in various PEM applications.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2018
National Category
Materials Chemistry
Identifiers
urn:nbn:se:umu:diva-155124 (URN)10.1039/c8ra07569g (DOI)000453914300053 ()
Funder
The Kempe FoundationsSwedish Energy AgencySwedish Research Council
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-04-29Bibliographically approved
Klechikov, A., You, S., Lackner, L., Sun, J., Iakunkov, A., Rebrikova, A., . . . Talyzin, A. V. (2018). Graphite oxide swelling in molten sugar alcohols and their aqueous solutions. Carbon, 140, 157-163
Open this publication in new window or tab >>Graphite oxide swelling in molten sugar alcohols and their aqueous solutions
Show others...
2018 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 140, p. 157-163Article in journal (Refereed) Published
Abstract [en]

Graphite oxides (GO) are intercalated rapidly by one to several layers of solvent when immersed in liquid but the GO solvates are typically unstable on air due to solvent evaporation. Here we study swelling of GO in solvents (sugar alcohols) with melting temperature point above ambient. Using in situ synchrotron radiation XRD experiments we demonstrated GO swelling in molten xylitol and sorbitol. The expanded GO structure intercalated with one layer of xylitol or sorbitol is preserved upon solidification of melt and cooling back to ambient conditions. The structure of solid solvates of GO with xylitol and sorbitol is based on non-covalent interaction and pristine GO can be recovered by washing in water. Intercalation of xylitol and sorbitol into GO structure in aqueous solutions yields similar but less ordered structure of GO/sugar alcohol solid solvates. Very similar inter-layer distance was observed for GO intercalated by sugar alcohols in melt and for GO immersed in sugar solutions. This result shows that sugar alcohols penetrate into GO inter-layer space without hydration shell forming 2D layers with orientation parallel to graphene oxide sheets. Therefore, hydration diameter of molecules should not be considered as decisive factor for permeation through graphene oxide inter-layers in multilayered membranes.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
graphene, graphene oxide, swelling
National Category
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-151276 (URN)10.1016/j.carbon.2018.08.033 (DOI)000450120200016 ()
Funder
EU, Horizon 2020Swedish Research CouncilÅForsk (Ångpanneföreningen's Foundation for Research and Development)The Kempe Foundations
Available from: 2018-08-31 Created: 2018-08-31 Last updated: 2018-12-20Bibliographically approved
Klechikov, A. (2018). Graphite oxides for preparation of graphene related materials: structure, chemical modification and hydrogen storage properties. (Doctoral dissertation). Umeå: Umeå University
Open this publication in new window or tab >>Graphite oxides for preparation of graphene related materials: structure, chemical modification and hydrogen storage properties
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Carbon materials have been studied for hydrogen storage for decades, but they showed too low capacity at ambient temperature compared to target values for practical applications. This thesis includes two parts. First one is fundamental study of graphite oxides (GO) structure and properties. Second part is focused on hydrogen storage properties of graphene related materials prepared using GO as a precursor.

We studied the effects of synthesis methods and oxidation degree on solvation/intercalation properties of GOs. New effect of temperature induced reversible delamination was observed for Hummers GO (HGO) immersed in liquid acetonitrile. Experiments with swelling of Brodie GO (BGO) in 1-octanol revealed parallel orientation of the intercalated solvent molecules relative to graphene oxide (GnO) layers. Chemical functionalization of GO in swelled state allowed us to synthesize the materials with subnanometer slit pores supported by molecular pillars. Structure and properties of pillared GO were characterized by variety of methods. Swelling properties of multilayered GnO membranes were compared to properties of precursor GO. GnO membranes were found to swell similarly to GO powders in some solvents and rather differently in other. Our experiments revealed important limitations in application of GO membranes for nanofiltration. Several parameters were found to affect the size of permeation “channels” provided by interlayers of GnO membrane structure: e.g. nature of solvent, pH of solutions and concentration of solutes.

Hydrogen storage parameters were studied for a set of graphene related materials with broad range of surface areas (SSA) (200 - 3300 m2/g). Hydrogen sorption weight percent (wt%) is found to correlate with SSA for all studied graphene materials following the trend standard for other nanostructured carbon materials. The highest hydrogen uptakes of ~1.2 wt% at 296 K and ~7.5 wt% at 77 K were measured for graphene material with SSA of over 3000 m2/g. Addition of Pd and Pt nanoparticles to graphene materials did not resulted in improvement of hydrogen storage compared to nanoparticles-free samples. No deviation from the standard wt% vs. SSA trends was also observed for pillared GO materials. Therefore, hydrogen storage properties of graphene related materials at room temperatures are not confirmed to be exceptional. However, high surface area graphene materials are found to be among the best materials for physisorption of hydrogen at liquid nitrogen temperature. Moreover, hydrogen storage capacity of 4 wt%, comparable to target values, was observed at temperature of solid CO2 (193 K) which can be maintained using common refrigeration methods.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2018. p. 117
Keywords
Graphite oxide, graphene oxide, hydrogen storage, nanomaterials, adsorption, surface area, pore volume
National Category
Other Physics Topics
Research subject
Materials Science
Identifiers
urn:nbn:se:umu:diva-144270 (URN)978-91-7601-841-5 (ISBN)
Public defence
2018-03-02, N430, Naturvetarhuset, Umeå, 13:15 (English)
Opponent
Supervisors
Available from: 2018-02-09 Created: 2018-01-29 Last updated: 2018-06-09Bibliographically approved
Iakunkov, A., Klechikov, A., Sun, J., Steenhaut, T., Hermans, S., Filinchuk, Y. & Talyzin, A. (2018). Gravimetric tank method to evaluate material-enhanced hydrogen storage by physisorbing materials. Physical Chemistry, Chemical Physics - PCCP, 20(44), 27983-27991
Open this publication in new window or tab >>Gravimetric tank method to evaluate material-enhanced hydrogen storage by physisorbing materials
Show others...
2018 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 44, p. 27983-27991Article in journal (Refereed) Published
Abstract [en]

The most common methods to evaluate hydrogen sorption (volumetric and gravimetric) require significant experience and expensive equipment for providing reproducible results. Both methods allow one to measure excess uptake values which are used to calculate the total amount of hydrogen stored inside of a tank as required for applications. Here we propose an easy to use and inexpensive alternative approach which allows one to evaluate directly the weight of hydrogen inside a material-filled test tank. The weight of the same tank filled with compressed hydrogen in the absence of loaded material is used as a reference. We argue that the only parameter which is of importance for hydrogen storage applications is by how much the material improves the total weight of hydrogen inside of the given volume compared to compressed gas. This parameter which we propose to name Gain includes both volumetric and gravimetric characterization of the material; it can be determined directly without knowing the skeletal volume of the material or excess sorption. The feasibility of the Gravimetric Tank (GT) method was tested using several common carbon and Metal Organic Framework (MOF) materials. The best Gain value of ∼12% was found for the Cu-BTC MOF which means that the tank completely filled with this material stores a 12% higher amount of hydrogen compared to H2 gas at the same PTconditions. The advantages of the GT method are its inexpensive design, extremely simple procedures and direct results in terms of tank capacity as required for industrial applications. The GT method could be proposed as a standard check for verification of the high hydrogen storage capacity of new materials. The GT method is expected to provide even better accuracy for evaluation of a material's performance for storage of denser gases like e.g. CO2 and CH4.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-154041 (URN)10.1039/c8cp05241g (DOI)000450660400026 ()30382273 (PubMedID)
Funder
EU, Horizon 2020, 696656EU, Horizon 2020, N785219The Kempe FoundationsSwedish Research Council, 2017-04173
Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2018-12-19Bibliographically approved
Talyzin, A., Mercier, G., Klechikov, A., Hedenström, M., Johnels, D., Wei, D., . . . Moons, E. (2017). Brodie vs Hummers graphite oxides for preparation of multi-layered materials. Carbon, 115, 430-440
Open this publication in new window or tab >>Brodie vs Hummers graphite oxides for preparation of multi-layered materials
Show others...
2017 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 115, p. 430-440Article in journal (Refereed) Published
Abstract [en]

Graphite oxides synthesized by one and two step Brodie oxidation (BGO) and Hummers (HGO) methods were analyzed by a variety of characterization methods in order to evaluate the reasons behind the difference in their properties. It is found that the Brodie method results in a higher relative amount of hydroxyl groups and a more homogeneous overall distribution of functional groups over the planar surface of the graphene oxide flakes. The higher number of carbonyl and carboxyl groups in HGO, detected by several methods, including XPS, NMR and FTIR, unavoidably results in defects of the graphene "skeleton", holes and overall disruption of the carbon-carbon bond network, stronger deviation from planar flake shape and poor ordering of the graphene oxide layers. It is also suggested that functional groups in HGO are less homogeneously distributed over the flake surface, forming some nanometer-sized graphene areas. The presence of differently oxidized areas on the GO surface results in inhomogeneous solvation and hydration of HGO and effects of inter- and intra-stratification. The proposed interpretation of the data explains the higher mechanical strength of multi-layered BGO membranes/papers, which are also less affected by humidity changes, thus providing an example of a membrane property superior to that of HGO.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
graphite, oxide
National Category
Condensed Matter Physics
Research subject
Physics
Identifiers
urn:nbn:se:umu:diva-130949 (URN)10.1016/j.carbon.2016.12.097 (DOI)000395601300045 ()
Available from: 2017-02-01 Created: 2017-02-01 Last updated: 2018-06-09Bibliographically approved
Klechikov, A., Sun, J., Baburin, I. A., Seifert, G., Rebrikova, A. T., Avramenko, N. V., . . . Talyzin, A. V. (2017). Multilayered intercalation of 1-octanol into Brodie graphite oxide. Nanoscale, 9(20), 6929-6936
Open this publication in new window or tab >>Multilayered intercalation of 1-octanol into Brodie graphite oxide
Show others...
2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 20, p. 6929-6936Article in journal (Refereed) Published
Abstract [en]

Multilayered intercalation of 1-octanol into the structure of Brodie graphite oxide (B-GO) was studied as a function of temperature and pressure. Reversible phase transition with the addition/removal of one layer of 1-octanol was found at 265 K by means of X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). The same transition was observed at ambient temperature upon a pressure increase above 0.6 GPa. This transition was interpreted as an incongruent melting of the low temperature/high pressure B-GO intercalated structure with five layers of 1-octanol parallel to GO sheets (L-solvate), resulting in the formation of a four-layered structure that is stable under ambient conditions (A-solvate). Vacuum heating allows the removal of 1-octanol from the A-solvate layer by layer, while distinct sets of (00 l) reflections are observed for three-, two-, and one-layered solvate phases. Step by step removal of the 1-octanol layers results in changes of distance between graphene oxide planes by similar to 4.5 angstrom. This experiment proved that both L- and A-solvates are structures with layers of 1-octanol parallel to GO planes. Unusual intercalation with up to five distinct layers of 1-octanol is remarkably different from the behaviour of small alcohol molecules (methanol and ethanol), which intercalate B-GO structure with only one layer under ambient conditions and a maximum of two layers at lower temperatures or higher pressures. The data presented in this study make it possible to rule out a change in the orientation of alcohol molecules from parallel to perpendicular to the GO planes, as suggested in the 1960s to explain larger expansion of the GO lattice due to swelling with larger alcohols.

National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-136327 (URN)10.1039/c7nr01792h (DOI)000402034400038 ()28509924 (PubMedID)
Funder
EU, Horizon 2020, 696656
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2018-06-09Bibliographically approved
Sun, J., Morales-Lara, F., Klechikov, A., Talyzin, A. V., Baburin, I. A., Seifert, G., . . . Giordani, S. (2017). Porous graphite oxide pillared with tetrapod-shaped molecules. Carbon, 120, 145-156
Open this publication in new window or tab >>Porous graphite oxide pillared with tetrapod-shaped molecules
Show others...
2017 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 120, p. 145-156Article in journal (Refereed) Published
Abstract [en]

Porous pillared graphene oxide (GO) materials were prepared using solvothermal reaction of Hummers GO with solution of Tetrakis(4-aminophenyl)methane (TKAm) in methanol. The intercalation of TKAm molecules between individual GO sheets, performed under swelling condition, results in expansion of inter-layer distance of GO from ∼7.5 Å to 13-14 Å. Pillaring GO with bulky, rigid 3D shaped TKAm molecules could be an advantage for the preparation of stable pillared structures compared to e.g. aliphatic or aromatic diamines. Insertion of TKAm molecules into inter-layer space of GO results in formation of interconnected network of sub-nanometer slit pores. The expanded GO structure prepared with optimized GO/TKAm composition shows Specific Surface Area (SSA) up to 660 m2/g which is among the highest reported for GO materials pillared using organic spacers. Modelling of GO structures pillared with TKAm molecules shows that maximal SSA of about 2300 m2/g is theoretically possible for realistic concentration of pillaring molecules in GO interlayers. Hydrogen sorption by pillared GO/TKAm is found to follow standard correlation with SSA both at ambient and liquid nitrogen temperatures with highest uptakes of 1.66 wt% achieved at 77 K and 0.25 wt% at 295 K. Our theoretical simulations show that pillared GO structures do not provide improvement of hydrogen storage beyond well-established physisorption trends even for idealized materials with subnanometer pores and SSA of 2300–3700 m2/g.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Physical Chemistry Condensed Matter Physics
Identifiers
urn:nbn:se:umu:diva-137608 (URN)10.1016/j.carbon.2017.05.007 (DOI)000403665000019 ()
Available from: 2017-07-10 Created: 2017-07-10 Last updated: 2018-06-09Bibliographically approved
Klechikov, A. & Talyzin, A. V. (2016). Comment on "Nanohole-Structured and Palladium-Embedded 3D Porous Graphene for Ultrahigh Hydrogen Storage and CO Oxidation Multifunctionalities". ACS Nano, 10(10), 9055-9056
Open this publication in new window or tab >>Comment on "Nanohole-Structured and Palladium-Embedded 3D Porous Graphene for Ultrahigh Hydrogen Storage and CO Oxidation Multifunctionalities"
2016 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 10, no 10, p. 9055-9056Article in journal, Editorial material (Refereed) Published
National Category
Nano Technology
Research subject
nanomaterials
Identifiers
urn:nbn:se:umu:diva-128901 (URN)10.1021/acsnano.6b03568 (DOI)000386423600002 ()27776405 (PubMedID)
Available from: 2016-12-19 Created: 2016-12-19 Last updated: 2018-06-09Bibliographically approved
Organisations

Search in DiVA

Show all publications