Few-layered WS2 nanosheets onto 1D CdS@ZnCdS as efficient visible-light photocatalyst for hydrogen evolution

Abstract

Exploiting highly efficient and non-expensive visible-light photocatalysts is a huge challenge for H2 photocatalytic production. Here we synthesized an efficient non-precious metal photocatalyst WS2/CdS@ZnCdS (WS2/CdS@ZCS) consisting of few-layered WS2 attached on the core/shell structure of CdS@ZnCdS (CdS@ZCS) via three-step hydrothermal and electrostatic adsorption methods, in which the morphology and structure of the components were regulated independently. The optimum photocatalytic H2 evolution rate of 8 wt% WS2/CdS@ZCS is 34860 μmol h−1 g−1, which is almost 5.2 times as high as that of pure CdS nanorods (6730 μmol h−1 g−1) and superior to most previously reported CdS-based photocatalysts. Moreover, it can maintain 91% of its initial hydrogen evolution rate after 20 hours photocatalytic experiment, indicating WS2/CdS@ZCS is very stable. A possible mechanism of H2 generation on WS2/CdS@ZCS photocatalyst is also proposed. It is thought that this work may provide a promising way to design nanosheets/1D core@shell heterostructured photocatalysts for high-performance and steady H2 production.