An Electron Bridge of Shared Atoms Mediated Cs3Bi2Br9/Bi2WO6 Z-Scheme Heterojunction for Photocatalytic CO2 Reduction

Abstract

Converting clean solar energy into chemical energy through artificial photosynthesis is an effective solution to solve the energy and environmental issues. Here, we report a Cs3Bi2Br9/Bi2WO6 (CBB/BWO) Z-scheme heterojunction constructed via electrostatic self-assembly, which facilitates efficient separation of photogenerated carriers and ensures the corresponding redox capacity of both components. By sharing Bi atoms, a Br−Bi−O bond is established between CBB and BWO, serving as an “electron bridge”. The electrons generated by BWO are efficiently channeled to CBB through the heterojunction-formed “electron bridge”, thereby achieving effective photocatalytic CO2 reduction. Under simulated sunlight conditions, it exhibits the highest CO yield of 72.52 μmol g−1 (without the addition of any precious metal, photosensitizers or sacrifices), which is approximately 7-fold and 18-fold greater than that of pure CBB and BWO, respectively. This work provides a more profound comprehension of the regulation of electron transfer through interfacial chemical bonds, thereby proposing a promising strategy for the development of efficient heterojunction photocatalysts for CO2 photoreduction.