Efficient treament of organic pollutants over CdS/graphene composites photocatalysts

CdS/graphene composites were obtained through a mild chemical reaction approach. Mnay techniques (XRD, TEM, UV-vis, XPS, etc.) were adopted to characterize the composites. The results indicate that CdS nanoparticles were dispersed on the surface of graphene nanosheets, and the composites exhibited improved specific surface area after adding graphene. The catalytic activity was assessed by monitoring the degradation of methyl orange, and the results indicate that 94% of methyl orange was degraded over the composites after irradiation for 120 min, higher than that of pure CdS. The excellent activity can be ascribed to higher specific surface area, boosted light absorption capacity, high carrier separation efficiency, and enhanced redoxability of the carriers. Ultraviolet-visible spectra, VB XPS spectroscopy, photocurrent curves, and photoluminescence tests were employed to confirm the excellent absorption properties, suitable band structure and efficient carriers separation of the composites, respectively. In addition, scavenging experiments demonstrated O-center dot(2)- exhitibed a key part during the catalytic degradation.