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

DOI: 10.3390/surfaces3020017 DOI Help

Authors: Marco Favaro (Università di Padova) , Mattia Cattelan (Università di Padova) , Stephen W. T. Price (Finden Ltd) , Andrea Russell (University of Southampton) , Laura Calvillo (Università di Padova) , Stefano Agnoli (Università di Padova) , Gaetano Granozzi (Università di Padova)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Surfaces , VOL 3 , PAGES 225 - 236

State: Published (Approved)
Published: June 2020
Diamond Proposal Number(s): 9550

Open Access Open Access

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 sulfur 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.

Journal Keywords: in line XPS-electrochemistry; operando XAS; HER

Diamond Keywords: Fuel Cells

Subject Areas: Chemistry, Materials, Energy


Instruments: B18-Core EXAFS

Added On: 22/06/2020 13:17

Documents:
surfaces-03-00017.pdf

Discipline Tags:

Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Catalysis Energy Materials Chemistry Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)