Hierarchical Sheet-on-Sheet ZnIn2S4/g-C3N4 Heterostructure with Highly Efficient Photocatalytic H2 production Based on Photoinduced Interfacial Charge Transfer

Abstract

We have realized in-situ growth of ultrathin ZnIn 2 S 4 nanosheets on the sheet-like g-C 3 N 4 surfaces to construct a “sheet-on-sheet” hierarchical heterostructure. The as-synthesized ZnIn 2 S 4/g-C 3 N 4 heterojunction nanosheets exhibit remarkably enhancement on the photocatalytic activity for H 2 production. This enhanced photoactivity is mainly attributed to the efficient interfacial transfer of photoinduced electrons and holes from g-C 3 N 4 to ZnIn 2 S 4 nanosheets, resulting in the decreased charge recombination on g-C 3 N 4 nanosheets and the increased amount of photoinduced charge carriers in ZnIn 2 S 4 nanosheets. Meanwhile, the increased surface-active-sites and extended light absorption of g-C 3 N 4 nanosheets after the decoration of ZnIn 2 S 4 nanosheets may also play a certain role for the enhancement of photocatalytic activity. Further investigations by the surface photovoltage spectroscopy and transient photoluminescence spectroscopy demonstrate that ZnIn 2 S 4/g-C 3 N 4 heterojunction nanosheets considerable boost the charge transfer efficiency, therefore improve the probability of photoinduced charge carriers to reach the photocatalysts surfaces for highly efficient H 2 production.