Few-Layered MoxW1-xS2-Modified CdS Photocatalyst: One-Step Synthesis with Bifunctional Precursors and Improved H2-Evolution Activity

Introducing W into MoS2 to fabricate MoxW1-xS2 is a promising strategy to optimize the active-site density and electrical conductivity of MoS2 to further improve its H-2-evolution efficiency. However, limited attention has been paid to developing facile and effective methods to prepare a MoxW1-xS2 H-2-evolution cocatalyst, especially the few-layered MoxW1-xS2, to boost the photocatalytic H-2-evolution activity of host photocatalyst materials. Herein, a well-designed MoxW1-xS2 cocatalyst with a few-layered structure of 5-7 layers and an interlayer spacing of 0.65 nm is in-situ grown on the CdS surface via a simple one-step solvothermal method with (NH4)(2)MoS4 and (NH4)(2)WS4 as the dual-functional precursors. In this case, the above dual-functional precursors can not only transform into the few-layered MoxW1-xS2 cocatalyst but also provide abundant S2- ions for the formation of the CdS host photocatalyst. The photocatalytic H-2-evolution results declare that the Mo0.5W0.5S2/CdS photocatalyst acquires the highest H-2-evolution rate of 2968.1 mu mol h(-1) g(-1), which is higher than that of MoS2/CdS by a factor of 3.5. The remarkably promoted H-2-evolution activity of the few-layered MoxW1-xS2/CdS is mainly ascribed to the speedy electron transport and efficient H-2-evolution reaction via the MoxW1-xS2 cocatalyst on CdS surface by W-introduction.