CoMoP hole transfer layer functionally enhances efficiency and stability of BiVO4 based photoanode for solar water splitting

Engineering the hole transfer layer is a promising approach to suppress the bulk charge recombination of photoanodes for enhancing solar water splitting performance. Herein, functional cobalt-molybdenum bimetallic phosphide (CoMoP) layer are inserted between bismuth vanadate (BiVO4) and NiFeOx oxygen evolution cocatalyst (OEC) as hole transfer layer to construct an integrated photoanode (NiFeOx/CoMoP/BiVO4). This state-of-the-art NiFeOx/CoMoP/BiVO4 photoanode not only achieves a superior photocurrent density of 5.82 mA/cm2 at 1.23 V vs a reversible hydrogen electrode (vs RHE), but also an outstanding 60 h long-term photostability (100 mW/cm2). Such excellent PEC performance can be attributed to the engineering CoMoP hole layer in NiFeOx/BiVO4, promoting hole transfer, retarding bulk charge recombination and accelerating the surface water oxidation kinetics. This study contributes to the role of the hole transfer layer and sheds light on the development of effective and stable photoanodes for PEC water splitting.