Solar Water Oxidation by Multicomponent TaON Photoanodes Functionalized with Nickel Oxide

Efficient solar-powered water oxidation over the TaON-based anodes requires coupling this photoactive n-type semiconductor to an electrooxidation catalyst to improve the otherwise unsatisfactory activity and stability. Herein, we examine how functionalization with electrodeposited nickel oxide, NiO_x , affects the performance of screen-printed TaON photoanodes post-necked with titania (TiO₂ -TaON). The effects of the NiO_x photo-electrodeposition parameters on the microstructure and photocatalytic performance of the resulting anodes are explored. Enhancements in the transient water oxidation photocurrent densities by sixfold vs. unmodified TiO₂ -TaON were achieved with the use of the NiO_x /TiO₂ -TaON photoanodes. Long-term stability tests reveal a slow but persistent degradation of the performance of the multicomponent photocatalysts under the severely oxidizing conditions of water photo-oxidation coincident with continuous morphological changes in the NiO_x deposits.