Ag2S and MoS2 as dual, co-catalysts for enhanced photocatalytic degradation of organic pollutions over CdS

CdS photocatalysts loaded with Ag2S and MoS2 as dual co-catalysts were prepared via a one-step in situ hydrothermal method using CdCl2·2.5H2O, H2MoO4, AgNO3·9H2O, and CS(NH2)2 as the raw materials. The as-prepared photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron micrograph, X-ray photoelectron spectroscopy, photoluminescence spectra, and Ultraviolet–Visible diffuse reflectance spectroscopy (UV–Vis DRS). The highest photocatalytic degradation rate was achieved for Ag2S/MoS2/CdS composites (87 %) compared to MoS2/CdS composites (66 %) and CdS (62 %) under visible light illumination for 60 min. The recycled photocatalytic experiments showed that the photocatalytic stability of CdS was improved with the introduction of Ag2S and MoS2. The improved photocatalytic performance of Ag2S/MoS2/CdS composites can be ascribed to the red shift of absorption edge, enhanced light absorption intensity, and the increased separation of the photoinduced electron–hole pairs, which was attributed to the synergetic effect of MoS2 and Ag2S on CdS. It was proven that Ag2S and MoS2 can act as effective dual co-catalysts to enhance the photocatalytic degradation activity of CdS.