Electrochemical Fabrication of MoO ₂ /MoO ₃ -Based Photo-Anodes for Water Splitting

Abstract

Photo-electrochemical cells are a promising technology for the environmentally-benign production of hydrogen using solar energy. In this kind of cells, a photo-active material is coated or deposited on a substrate (e.g. fluorine-doped tin dioxide(FTO)-coated glass) which acts as current collector and support. In this research project, a molybdenum oxide layer is electrochemically deposited on the surface of a FTO-coated glass working electrode immersed in a solution containing 0.075 M molybdate (MoO4 2-), 0.075 M nickel sulfate (NiSO4•6H2O), 0.5 M tri-sodium citrate (Na3C6H5O7•2H2O) and 0.7 M ammonium hydroxide (NH4OH), by applying a potential of -1.377 V vs Ag/AgCl (3 M KCl) during 3 hours. The characterization of the photo-anodes produced suggests that they present semiconducting and catalytic properties which make them attractive for their application in a photo-electrochemical cell for water splitting.

All-Electrochemically Grown Sb2Se3/a-MoSx Photocathodes for Hydrogen Production: The Effect of the MoSx Layer on the Surface Recombination and Photocorrosion of Sb2Se3 Films

“…25 As already reported by other authors, molybdenum oxides have ntype properties and facilitate the separation of the photogenerated charges through a p-n junction, which may be also associated with this sudden increase in photocurrent. 40,41 However, it is difficult to distinguish the XPS spectrum between Mo−S and Mo−O bonds. The decrease in absorber coverage is another factor that may be involved since MoO 3 (and other oxidized species) is soluble in a strongly acidic medium, 42 part of the cocatalyst layer may have been dissolved during photoelectrolysis.…”