Decoration of WS_2 as an effective noble-metal free cocatalyst on ZnIn_2S_4 for enhanced visible light photocatalytic hydrogen evolution

摘要

In this work, a series of WS2/ZnIn2S4 composite photocatalysts containing different WS2 cocatalyst amounts were prepared through a facile hydrothermal approach. The prepared WS2/ZnIn2S4 composite photocatalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectra (DRS), and their visible-light driven photocatalytic hydrogen evolution performances were also investigated. It was revealed that the loading of WS2 cocatalyst could greatly boost the photocatalytic hydrogen evolution activity of ZnIn2S4 , and the 3% WS2/ZnIn2S4 sample achieved the highest hydrogen production rate of 199.1 mu mol/h/g, which was nearly 6 times higher than ZnIn2S4 and was even comparable to the conventional Pt/ZnIn2S4 photocatalyst. The improved photocatalytic performance of WS2/ZnIn2S4 could be ascribed to the promotion of separation and migration of photogenerated charge carriers derived from the heterostructure formed at the interface between ZnIn2S4 and WS2 . Thus, this work proves a great potential of WS2 as a cost-effective cocatalyst for semiconductor-based photocatalytic hydrogen production. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.