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In situ study of graphene oxide quantum dot-MoSx nanohybrids as hydrogen evolution catalysts

In situ study of graphene oxide quantum dot-MoSx nanohybrids as hydrogen evolution catalysts
In situ study of graphene oxide quantum dot-MoSx nanohybrids as hydrogen evolution catalysts
Graphene quantum dots (GOQDs)-MoSx nanohybrids with different MoSx stoichiometries (x = 2 and 3) were prepared in order to investigate their chemical stability under hydrogen evolution reaction (HER) conditions. Combined photoemission/electrochemical (XPS/EC) measurements and operando X-ray absorption spectroscopy (XAS) were employed to determine the chemical changes induced on the MoSx-based materials as a function of the applied potential. This in situ characterization indicates that both MoS2 and MoS3 materials are stable under operating conditions, although sulphur terminal sites in the MoS3 nanoparticles are converted from S-dimer (S22-) to S-monomer (S2-), which constitute the first sites where the hydrogen atoms are adsorbed for their subsequent evolution. In order to complete the characterization of the GOQDs-MoSx nanohybrids, the composition and particle size were determined by X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD) and Raman spectroscopy; whereas the HER activity was studied by conventional electrochemical techniques.
in line XPS-electrochemistry, operando XAS, HER
2571-9637
225-236
Favaro, Marco
e7967c96-88aa-47a2-9642-b3e3a51f1072
Cattelan, Mattia
404a3fa0-75d0-4ed1-a6cb-9aa95fb0bb9a
Price, Stephen WT
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Russell, Andrea E.
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Calvillo, Laura
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Agnoli, S.
aed87283-7fc7-489a-9c88-766e21c1f835
Granozzi, Gaetano
e1561b71-a42d-4c72-9028-3fb07183fceb
Favaro, Marco
e7967c96-88aa-47a2-9642-b3e3a51f1072
Cattelan, Mattia
404a3fa0-75d0-4ed1-a6cb-9aa95fb0bb9a
Price, Stephen WT
5d3310d0-cf30-45e6-ba44-4bf87ade3b8d
Russell, Andrea E.
b6b7c748-efc1-4d5d-8a7a-8e4b69396169
Calvillo, Laura
05ff21ed-97ce-4ea4-9b73-f4c181be59b0
Agnoli, S.
aed87283-7fc7-489a-9c88-766e21c1f835
Granozzi, Gaetano
e1561b71-a42d-4c72-9028-3fb07183fceb

Favaro, Marco, Cattelan, Mattia, Price, Stephen WT, Russell, Andrea E., Calvillo, Laura, Agnoli, S. and Granozzi, Gaetano (2020) In situ study of graphene oxide quantum dot-MoSx nanohybrids as hydrogen evolution catalysts. Surfaces, 3 (2), 225-236. (doi:10.3390/surfaces3020017). (In Press)

Record type: Article

Abstract

Graphene quantum dots (GOQDs)-MoSx nanohybrids with different MoSx stoichiometries (x = 2 and 3) were prepared in order to investigate their chemical stability under hydrogen evolution reaction (HER) conditions. Combined photoemission/electrochemical (XPS/EC) measurements and operando X-ray absorption spectroscopy (XAS) were employed to determine the chemical changes induced on the MoSx-based materials as a function of the applied potential. This in situ characterization indicates that both MoS2 and MoS3 materials are stable under operating conditions, although sulphur terminal sites in the MoS3 nanoparticles are converted from S-dimer (S22-) to S-monomer (S2-), which constitute the first sites where the hydrogen atoms are adsorbed for their subsequent evolution. In order to complete the characterization of the GOQDs-MoSx nanohybrids, the composition and particle size were determined by X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD) and Raman spectroscopy; whereas the HER activity was studied by conventional electrochemical techniques.

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More information

Accepted/In Press date: 5 June 2020
Keywords: in line XPS-electrochemistry, operando XAS, HER

Identifiers

Local EPrints ID: 441506
URI: http://eprints.soton.ac.uk/id/eprint/441506
ISSN: 2571-9637
PURE UUID: 836a9b8a-ab81-4435-8405-5c7cd54f0e7a
ORCID for Andrea E. Russell: ORCID iD orcid.org/0000-0002-8382-6443

Catalogue record

Date deposited: 16 Jun 2020 16:31
Last modified: 07 Oct 2020 01:41

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Contributors

Author: Marco Favaro
Author: Mattia Cattelan
Author: Stephen WT Price
Author: Laura Calvillo
Author: S. Agnoli
Author: Gaetano Granozzi

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