Coupling Benzylamine Oxidation with CO Photoconversion to Ethanol over a Black Phosphorus and Bismuth Tungstate S-Scheme Heterojunction.

Photoconversion of CO and H O into ethanol is an ideal strategy to achieve carbon neutrality. However, the production of ethanol with high activity and selectivity is challenging owing to the less efficient reduction half-reaction involving multi-step proton-coupled electron transfer (PCET), a slow C-C coupling process, and sluggish water oxidation half-reaction. Herein, a two-dimensional/two-dimensional (2D/2D) S-scheme heterojunction consisting of black phosphorus and Bi WO (BP/BWO) was constructed for photocatalytic CO reduction coupling with benzylamine (BA) oxidation. The as-prepared BP/BWO catalyst exhibits a superior photocatalytic performance toward CO reduction, with a yield of 61.3 μmol g  h for ethanol (selectivity of 91 %).In situ spectroscopic studies and theoretical calculations reveal that S-scheme heterojunction can effectively promote photogenerated carrier separation via the Bi-O-P bridge to accelerate the PCET process. Meanwhile, electron-rich BP acts as the active site and plays a vital role in the process of C-C coupling. In addition, the substitution of BA oxidation for H O oxidation can further enhance the photocatalytic performance of CO reduction to C H OH. This work opens a new horizon for exploring novel heterogeneous photocatalysts in CO photoconversion to C H OH based on cooperative photoredox systems.