Sandwich-like P-doped h-BN/ZnIn2S4 nanocomposite with direct Z-scheme heterojunction for efficient photocatalytic H2 and H2O2 evolution

Abstract

The sustainable conversion from solar energy to chemical energy is realized by using photocatalytic technology to produce hydrogen and hydrogen peroxide. In this work, the construction of a direct Z-scheme heterojunction is of great significance for improving the efficiency and stability of photocatalytic hydrogen evolution (PHE) and photocatalytic hydrogen peroxide production (PHP). In this study, P-doped h-BN (PBN) nanosheets are used to support the in-situ growth of ZnIn2S4 nanoflowers via wet chemical method, and sandwich-like PBN/ZnIn2S4 hierarchical heterostructures are successfully synthesized. The PHE performance of PBN/ZnIn2S4 (∼59.46 μmol/h) is ∼ 2.35 times than that of the original ZnIn2S4 (∼25.27 μmol/h), and the PHP performance (∼122.82 μmol/L/h) is 39.37 times than that of PBN (∼3.12 μmol/L/h). The excellent photocatalytic performance of PBN/ZnIn2S4 can be attributed to the following points: (1) the acceleration of the separation of photogenerated electron-hole pairs induced by the formation of Z-scheme heterostructure; (2) reasonable design and construction of sandwich-like PBN/ZnIn2S4 hierarchical heterostructure; (3) the promotion the migration and separation of photogenerated carriers by the built-in electric field. This work provides new ideas for the development of high-efficiency PHE and PHP Z-scheme heterojunction photocatalyst design.