Efficient charge separation in hierarchical NiS@ZnIn2S4 hollow nanospheres for photocatalytic water splitting

Abstract

In this work, hierarchical NiS@ZnIn2S4 heterostructure was developed by constructing ultra-thin ZnIn2S4 (ZIS) nanosheets on hollow NiS nanospheres for hydrogen production from photocatalytic water splitting. The NiS@ZIS displayed a strong optical absorption ability in the visible region and a high specific surface area of 33.14 m2/g. The Type-I band alignment in NiS@ZIS heterostructure was determined by the combination of UV–vis absorption spectroscopy and Mott-Schottky curves. The photocatalytic hydrogen production of NiS@ZIS (1.24 mmol g−1 h−1) was nearly 5.6 times higher than that of ZIS under visible light, in the absence of any co-catalyst and sacrificial agent. The separation and migration of charge in NiS@ZIS were characterized by a series of spectroscopy and photo/electrochemical tests, which verified the efficient charge transfer from ZIS to NiS.