Graphene-modified BiMo0.03V0.97O4 thin-film photoanode for enhanced photoelectrochemical water splitting performance

Abstract

In this study, graphene is coated on the surface of an Mo-doped BiMo_0.03V_0.97O₄ (BiMoVO) film by galvanostatic reduction deposition. The BiMoVO/graphene (BiMoVO/G) thin-film photoanode exhibits the optimal photoelectrochemical performance with the graphene deposition time of 600 s. The photoinduced current density is 3.5 mA cm⁻² at the bias potential of 1 V, which increases by approximately 2.3 times that of the BiMoVO thin-film photoanode. Moreover, the BiMoVO/G photoanode shows higher photoelectrochemical stability as well. The improvement of the photoelectrochemical properties is attributed to the graphene coating, which acts as the receptor of the photogenerated electrons from the BiMoVO film. Therefore, the photogenerated electrons can be rapidly transferred to the substrate through the graphene channel, enhancing the separation efficiency of the photogenerated electron-hole pairs and prolonging the lifetime of the photoinduced electrons.