Direct Z-scheme charge transfer of Bi2WO6/InVO4 interface for efficient photocatalytic CO2 reduction

InVO4 possesses great potential in photocatalytic CO2 conversion. It is still highly desired to develop efficient strategies of photocatalyst fabrication to prevent its attenuated activity caused by the rapid recombination of photogenerated electron-hole. Herein, a direct Z-scheme heterojunction of Bi2WO6/InVO4 nanosheets is constructed via two-step hydrothermal synthesis. The Bi2WO6/InVO4 composite exhibits a superior photocatalytic performance toward CO2 reduction into CO and CH4 under visible light irradiation. The CO evolution rate reaches up to 17.97 μmol g−1 h−1, while the CH4 production rate is 1.13 μmol g−1 h−1, which are higher than those catalyzed by bare InVO4 and bare Bi2WO6. Based on the photoelectrochemical results, hydroxyl radical test, Scanning Kelvin Probe (SKP) and electron spin resonance (ESR) investigation, the enhanced activity of CO2 reduction can be attributed to a Z-scheme electron transfer at the interface to promote spatial charge separation, which effectively preserves the reduction ability of photoelectron on the conduction band of InVO4 for CO2 conversion.