Synergistically promoted charge separation/transfer in a ZnO nanosheet photoanode via the incorporation of multifunctional 3DrGO

Abstract

Herein, we report a robust strategy to markedly promote charge separation and transfer via electrodepositing ZnO nanosheets into a cross-linked porous three-dimensional reduced graphene oxide (3DrGO) network structure to form a ZnO/3DrGO photoanode. In addition to the high electrical conductivity and 3D porous architecture, the photothermal effect of 3DrGO activated by a near-infrared (NIR) laser or NIR light of solar radiation can be used to increase the temperature of the photoanodes in situ, further enhancing the charge transfer efficiency of ZnO nanosheets. With the synergistic effect of 3DrGO, the photocurrent density of the ZnO/3DrGO photoanode (2.03 mA cm⁻²) is about three times higher than that of the pure ZnO photoanode (0.51 mA cm⁻²) at 1.23 V vs. reversible reference electrode (V_RHE). This work provides an effective strategy for improving the PEC water splitting performance of photoanodes via the incorporation of multifunctional 3D porous architecture rGO.