BiVO4/Bi2S3 Z-scheme heterojunction with MnOx as a cocatalyst for efficient photocatalytic CO2 conversion to methanol by pure water

The design of Z-scheme heterostructure is an attractive strategy for efficient charge separation at the interface to boost photocatalytic CO2 reduction. Herein, BiVO4/Bi2S3 composite is synthesized through an in situ selective epitaxial growth of Bi2S3 nanosheets on the (010) facets of BiVO4. In situ X-ray photoelectron spectroscopy, first-principle simulation, and other characterization tools unveil that the delocalized electrons in Bi2S3 nanosheets transfer to the BiVO4 within BiVO4/Bi2S3 heterostructure, generating an internal electric field (IEF) at the interfaces, directing from Bi2S3 to BiVO4. The IEF drives the photoinduced electrons in BiVO4 to Bi2S3 under light irradiation, establishing direct BiVO4/Bi2S3 Z-scheme heterojunction. Moreover, the MnOx cocatalyst is selectively loaded on the (110) facet of BiVO4 by photodeposition. The MnOx/BiVO4/Bi2S3 heterostructures convert CO2 to methanol with unity selectivity and stoichiometric O2 production, which is proved by isotopic labeling. This work provides an avenue to design unique heterostructures for CO2 conversion and other applications.