MoO3/BiVO4 heterojunction modified with cobalt-manganese layered double hydroxide cocatalyst for photoelectrochemical water oxidation

To improve the charge recombination and poor oxygen evolution reaction (OER) kinetics of BiVO4, in this paper, a high-performance CoMn-LDH/MoO3/BiVO4 photoanode was synthesized by a simple electrodeposition and calcination method. CoMn-LDH/MoO3/BiVO4 shows a photocurrent density of 3.78 mA cm-2 at 1.23 V vs. RHE, which is 3.78 times higher than that of pure BiVO4 with negative shift onset potentials of 330 mV. The maximum applied bias photon-to-current efficiency (ABPE) and incident photon-to-current conversion efficiency (IPCE) are 1.24 % and 55.5 %, respectively, which are 13.8 and 12.5 times higher than those of pure BiVO4. In-depth studies demonstrate that the MoO3/BiVO4 heterojunction can better drive the transfer of photogenerated carriers and suppress bulk charge recombination, CoMn-LDH improves the OER kinetics and broadens the absorption of visible light, their synergistic effect significantly enhances charge separation and light harvesting of BiVO4. This work provides a facile electrodeposition method to fabricate highly efficient photoanodes for solar-driven water splitting.