Preparation of NiS/ZnIn(2)S(4) as a superior photocatalyst for hydrogen evolution under visible light irradiation

In this study, NiS/ZnIn(2)S(4) nanocomposites were successfully prepared via a facile two-step hydrothermal process. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Their photocatalytic performance for hydrogen evolution under visible light irradiation was also investigated. It was found that the photocatalytic hydrogen evolution activity over hexagonal ZnIn(2)S(4) can be significantly increased by loading NiS as a co-catalyst. The formation of a good junction between ZnIn(2)S(4) and NiS via the two step hydrothermal processes is beneficial for the directional migration of the photo-excited electrons from ZnIn(2)S(4) to NiS. The highest photocatalytic hydrogen evolution rate (104.7 μmol/h), which is even higher than that over Pt/ZnIn(2)S(4) nanocomposite (77.8 μmol/h), was observed over an optimum NiS loading amount of 0.5 wt %. This work demonstrates a high potential of the developing of environmental friendly, cheap noble-metal-free co-catalyst for semiconductor-based photocatalytic hydrogen evolution.