Efficient photocatalytic degradation of rhodamine B over CdS sensitized SiO2-HNb3O8 under visible light

Abstract

CdS/SiO2-HNb3O8 and CdS-HNb3O8 composite photocatalysts were developed for rhodamine B photodegradation under visible light. The characteristics of samples were investigated by XRD, SEM, TEM, PL, and UV-visible absorption spectroscopy. A liquid phase deposition method and an impregnation-gas phase deposition method were adopted for the loading of CdS onto SiO2-HNb3O8. All the composite materials show improved photocatalytic activities than the component materials for rhodamine B photodegradation under visible light. With better CdS dispersion and expanded interlayer distance of HNb3O8, the CdS/SiO2-HNb3O8 sample prepared by the novel impregnation-gas phase deposition method showed better activity than the counterpart prepared by conventional liquid phase deposition, CdS-pillared HNb3O8, and some reference samples such as P25, nitrogen-doped TiO2, and Bi2WO6. The enhanced photocatalytic activity of the CdS/SiO2-HNb3O8 composite is ascribed to the interface charge transfer between the two component materials, as well as the layered structure and the intercalation properties of SiO2-HNb3O8.