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 (TiO 2 –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 TiO 2 –TaON were achieved with the use of the NiO x /TiO 2 –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.