Promoting the photocatalytic H2 evolution activity of CdLa2S4 nanocrystalline using few-layered WS2 nanosheet as a co-catalyst

Abstract

In this work, a series of few-layered WS2 nanosheets were fabricated through an ultrasonic stripping method assisted by a hydrothermal process, then the WS2/CdLa2S4 composites were prepared by growing CdLa2S4 nanocrystallines in situ on the surface of few-layered WS2 nanosheets through an ultrasonic stripping method followed by a hydrothermal process. Investigation shows that the prepared WS2/CdLa2S4 composite shows an excellent photocatalytic activity toward hydrogen evolution from water with visible light response. The optimized content of few-layer of WS2 nanosheet was estimated to be around 5 wt% of CdLa2S4 nanocrystalline and the corresponding hydrogen evolution rate is about 6 times higher than that of single phase of CdLa2S4 nanocrystalline. Furthermore, the WS2/CdLa2S4 composites still keep high photocatalytic activity after 4 times circles. Combining few-layered WS2 nanosheets as a co-catalyst with CdLa2S4 nanocrystallines not only facilitate the efficient separation of photogenerated carriers, but also promote more active sites for hydrogen evolution. Considering its excellent photocatalytic activity toward H2 evolution with visible light response and photochemistry stability, the obtained WS2/CaLa2S4 composite photocatalyst has promising application for practical photocatalytic H2 production from H2O drived by solar energy.