CoMo-LDHs two-dimensional nanosheets grown in BiVO4 and enhanced photoelectrochemical water oxidation

Abstract

CoMo-LDHs grown on BiVO₄ (BVO) worm-like structures (BVO@CoMo-LDHs) were prepared by hydrothermal method. BVO@CoMo-LDHs can greatly increase the reaction contact area and provide more reaction active sites, thus greatly improving the hydrolysis capacity of photoelectric chemistry (PEC). The BVO@CoMo-LDHs photoanode exhibits excellent photoelectric performance under neutral electrolyte conditions. The optical current density reached 4.3 mA/cm², which was three times that of the naked BVO (1.5 mA/cm²). CoMo-LDHs structure was found to inhibit V⁵⁺ hydrolysis, thus extending lifespan. In the study of the electron transfer kinetics, the step from ∗ OOH to O₂ is identified as a rate-determining step, which favors the desorption of O₂ and accelerates the reaction. According to the work function and electron differential density calculation, a built-in electric field will be generated at the interface, determining the electron transfer direction and forming the Ⅱ-type heterojunction, thus reducing the overall carrier recombination.