First principles study of the photo-oxidation of water on tungsten trioxide (WO3)

TitleFirst principles study of the photo-oxidation of water on tungsten trioxide (WO3)
Publication TypeJournal Article
Year of Publication2009
AuthorsValdes A, Kroes GJ
JournalJournal of Chemical Physics
Date PublishedMar 21
ISBN Number0021-9606
Accession Number
Keywordsab-initio, adsorption, atomically smooth, augmented-wave method, density functional theory, electrolytes, free energy, molecular-dynamics, oxidation, photoelectrochemical properties, photoelectrochemistry, reaction kinetics theory, rutile tio2(110) surface, semiconductor photocatalyst, surface chemistry, thin-film electrodes, total-energy calculations, tungsten compounds, visible-light irradiation, water

The photo-oxidation of water on the monoclinic P2(1)/nWO(3) (200, 020, and 002) surfaces is investigated using density functional theory calculations, employing the PW91-generalized gradient approximation, and the method developed by Norskov [J. Phys. Chem. B 108, 17886 (2004)] based on the free energy differences between the reaction intermediates. We first relax the bulk material unit cell and then investigate the relative stability of different surface terminations of WO3 and analyze the overpotential needed for the photoelectrolysis of water. We found that the rate limiting step is the transfer of a proton from the surface adsorbed OH to the electrolyte, and that the computed overpotential for O-2 evolution (1.04 V) is available upon illumination of the surface with visible light.