Photocatalytic Property of Eu/BiVO_4 Photocatalyst by Citric Acid Sol-Gel Method

Eu3+-doped BiVO4 photocatalyst was synthesized by complexing Sol-Gel method using citric acid as chelate,and characterized with X-ray photoelectron spectroscope(XPS),X-ray diffraction(XRD),scanning electron microscope(SEM),specific surface area(BET) and UV-Vis diffuse reflectance spectroscope(DRS).The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange(MO) solution under visible light.It revealed that pure BiVO4 and all the Eu3+ doped samples were monoclinic phase and no peaks of any other phases or impurities were detected.It was also found that doping Eu3+ increased the amount of V4+ and oxygen vacancies.In addition,the light absorption edges of Eu3+ doped BiVO4 had extended a red shift compared with that of pure BiVO4.However,Eu3+ doping had little influence on morphology and specific surface area.The appropriate amount of Eu3+ doping could signifcantly increase the photocatalytic activity and the highest photocatalytic degradation rate was about 95% when the Eu3+ doping amount was 0.2%,which was more 62% than that of pure BiVO4 under 50 min visible light irridation.