Physical vapor deposition of mixed-metal oxides based on Fe, Co and Ni as water oxidation catalysts

Physical vapor deposition (PVD) techniques are proposed as high performing and easily tunable methods to synthesize mixed-metal oxides thin films as water oxidation catalysts (WOC). These techniques allow us to have a good control on the catalyst film surface morphology and crystallinity, with good adhesion of the catalysts on electrodes. Pure and binary metal oxides thin films based on Fe, Co and Ni were synthesized using electron beam deposition (EBD). WOC films are systematically studied through SEM microscopy, Raman spectroscopy and XPS analysis. Electrochemical characterization has been carried out to investigate the relevance of synergistic effects towards the water oxidation reaction. Among all the mixed oxides Ni–Fe oxide showed the best catalytic results.