Fast and effective electron transport in a Au–graphene–ZnO hybrid for enhanced photocurrent and photocatalysis

Abstract

A novel ZnO nanosheet aggregated hollow sphere (nSAHS) has been hydrothermally synthesized. Wrapping Au/reduced graphene oxide (Au/rGO) onto the ZnO nSAHS facilitates electron transfer at the ZnO interface. The photoinduced charge transfer of the Au/rGO/ZnO hybrid has been characterized using photoluminescence (PL) and a time-resolved PL decay profile. The quenched PL emission of Au/rGO/ZnO indicates decreased electron–hole pair recombination and facilitated electron transport, which results from the large surface area of the ZnO nSAHS structure, good physical adsorption of Au/rGO onto ZnO, and the excellent chemical interaction at the Au/rGO–ZnO interface. The Au/rGO/ZnO hybrid exhibits fast (4.46 ps) and effective (80.49%) charge transfer at the hybrid interface, indicating that Au/rGO/ZnO has better photocurrent responses and photocatalytic activities than rGO/ZnO and ZnO.