Dual-layer cocatalysts of Co-Pi and Ni(OH)2 on BiVO4 photoanodes for efficient water oxidation

Slow oxygen evolution kinetics and severe corrosion limit the further application of BiVO4 photoelectrodes in photoelectrochemical water splitting. Here, BiVO4/Co–Pi/Ni(OH)2 photoanodes were synthetized with the aim of improving their photoelectric conversion efficiency and stability. Compared with a pure BiVO4 photoanode, the BiVO4/Co–Pi/Ni(OH)2 photoanode enhanced the photocurrent from 1.1 to 4.5 mA/cm2 at 1.23 V versus the reversible hydrogen electrode. In addition, Ni(OH)2 acted as a corrosion protection layer on the surface of the photoanode, allowing the BiVO4/Co–Pi/Ni(OH)2 photoanode to exhibit excellent stability.