SynergeticEffects of Dual Electrocatalysts for High-PerformanceSolar-Driven Water Oxidation

Integration of electrocatalysts (ECs) with photoabsorbers is indispensable for high-performance solar water splitting. However, how the interaction between different ECs affects the performance is less explored. In the model system of the Si-based photoanode paired with different transition-metal-based EC dual layers, the oxygen evolution reaction with high efficiency and stability is obtained at low cost via synergetic effects of dual ECs. The spontaneous mutual doping between the EC dual layers greatly increases the conductivity of the electrode, thus facilitating the interfacial charge transfer, and the EC interlayer with high hole-accumulation ability can dramatically improve the hole collection capacity of the EC overlayer. In addition, the dynamic cycle of dissolution, diffusion, and deposition of a tiny amount of metal species between the EC dual layers favors the electrode stability. This work provides insightful guidance to interface design of high-performance devices for solar energy conversion.