Photocatalytic H₂ Evolution on MoS₂/CdS Catalysts under Visible Light Irradiation

Abstract

Photocatalytic H2 production on MoS2/CdS photocatalysts in the presence of different sacrificial reagents under visible light (λ > 420 nm) has been investigated. The transformation process of the Mo species loaded on CdS, together with the junctions formed between MoS2 and CdS, was clearly demonstrated with X-ray photoelectron spectroscopy and transmission electron microscopy. Photocatalytic H2 evolution was optimized for MoS2/CdS catalysts. The 0.2 wt % MoS2/CdS catalyst calcined at 573 K achieves the highest overall activity for H2 evolution, and the 0.2 wt % MoS2/CdS catalyst demonstrates even higher activity than the 0.2 wt % Pt/CdS, irrespective of different sacrificial reagents used. The junctions formed between MoS2 and CdS play an important role in enhancing the photocatalytic activity of MoS2/CdS catalysts. Electrochemical measurements indicate that MoS2 is an excellent H2 evolution catalyst, which is another very important factor responsible for the enhancement of the photocatalytic activity of MoS2/CdS catalysts.