Preparation of Pr~(3+)∶Y_2SiO_5/TiO_2 nanocomposites and its application in photocatalytic degradation of dyes under visible light irradiation

In order to enlarge the utilization ratio of the visible light,the Pr3+∶Y2SiO5/TiO2 composite was prepared by sol-gel method.The as-synthesized samples were characterized by X-ray diffraction,transmission electron microscopy,and ultraviolet-visible absorption spectra.Meanwhile,the composite powder(prepared under different conditions) degradation of RhB was studied.All the results proved that the Pr3+∶Y2SiO5/TiO2 had more excellent photocatalytic activities than pure TiO2,mixed powders(the mixture of Pr3+∶Y2SiO5 powder and TiO2 powder).Of which,as an upconversion luminescence agent,the Pr3+∶Y2SiO5 can transform the visible light into ultraviolet light,satisfying the requirement of TiO2 for photocatalytic degradation.In addition,the photocatalytic mechanics of the degradation reaction was investigated.