2D/2D Heterostructured CdS/WS2 with Efficient Charge Separation Improving H-2 Evolution under Visible Light Irradiation

摘要

Efficient Efiicient water splitting for H-2 evolution sender visible light irradiation has attracted more attention for solving the global environmental and energy issues, but it is still a major, challenge to develop an earth-abundant and effluent photocatalyst. Herein, we report two-dimensional (2D))/2D heterostructured CdS/WS2, (CdS/WS2), composed of nano sheet CdS (CdS) and nanosheet WS2 (WS2), as an efficient photocatalyst for H-2 evolution. As a noble metal-free visible light-driven catalyst for H-2, evolution, CdS/WS2 with 10 wt % WS2 exhibited the largest H-2 evolution rate of 14.1 mmol g(-1) h(-1) under visible light,irradiation to be 8 times larger than that if pure Cds. The lifetime and dynamics of photogenerated electrons were evaluated by femtosecond time-resolved diffuse reflectance spectroscopy, indicating that WS2 works as an electron-trapping site and a cocatalyst to cause H-2 evolution under visible light irradiation. This work suggests that Cds/Ws(2) has great potential as a low-cost and highly efficient photocatalyst for water splitting.