Dual-functional reaction strategy boosts carbon dioxide reduction by coupling with selective benzyl alcohol oxidation on nano-Au/BiOCl photocatalysts

Abstract

Photocatalytic CO2 reduction without using sacrificial agents remains a big challenge. Herein, we report a dual-functional reaction on the Au-decorated 3-dimensional BiOCl nano-photocatalyst (Au/3D-BOC) that couples photocatalytic CO2 reduction with benzyl alcohol (BA) oxidation. On the optimized 1.0% Au/3D-BOC photocatalyst, the CO production rate reached 0.17 µmol cm-2 h−1 under AM 1.5 solar simulator light source, and the BA conversion was 48.04% with benzaldehyde (BAD) selectivity above 99%. The density functional theory (DFT) calculations demonstrate the decrease of the reaction thermodynamic energy barriers after loading Au. And various characterizations reveal the dependence of the interaction between Au NPs and 3D-BOC on Au loading, which is essential to separating photogenerated carriers and prolonging their lifetime. On this basis, the reaction pathways of CO2 photoreduction and selective BA oxidation over Au/3D-BOC were proposed. This work provides a new approach to promoting CO2 reduction and BA oxidation with high economic benefits.