Ternary Photoanodes with AgAu Nanoclusters and CoNi-LDH for Enhanced Photoelectrochemical Water Oxidation.

Atomically precise metal nanoclusters (NCs) present new opportunities for creating innovative solar-powered photoanodes due to their extraordinary physicochemical properties. Nevertheless, ultrasmall metal NCs tend to aggregate and lack active sites under light irradiation, which severely limits their widespread application. We have developed a strategy to design efficient ternary photoanodes by successively modifying AgAu NCs and CoNi-LDH on BiVO4 substrates using versatile impregnation and electrodeposition. The electronic properties of AgAu NCs facilitate the rapid transfer of photogenerated carriers on BiVO4 and CoNi-LDH. Additionally, ultrathin CoNi-LDH acts as a hole-collecting layer, which quickly extracts holes to the electrode/electrolyte interface. The synergistic effect and the matched energy levels between the ternary heterostructures promote the OER process, which significantly improved the photoelectrochemical (PEC) water oxidation performance. This study presents a new idea for further exploration of metal nanocluster-based PEC systems.