Preparation Of AgBr/LnVO₄?Ln=Gd,Y,Eu? Composite And Its Photocatalytic Activity In Water Purificatoin

Photocatalysis technique shows great significance for sewage treatment.TiO2 semiconductor photocatalyst is the most typical photocatalyst,which can effectively degrade organics in sewage.However,its wide band gap leads to its limited response to sun light.It cannot use the visible light which occupies a larger proportion of natural light.Different from TiO2,metal vanadate catalyst has a narrower band gap and can react with visible light.Hence,this kind of photocatalyst has a better development prospect.Of course,the photocatalytic activity of pure metal vanadate is still low.The modification to increase its photocatalytic efficiency is needed.AgBr as a photosensitive material is widely used in film.Meanwhile,it is reported that AgBr may be a good co-catalyst in the photocatalytic reaction.Therefore,it can be speculated that the doping of metal vanadate with AgBr may generate a very promising photocatalyst.Therefore,this paper synthesized AgBr/LnVO4(Ln=Gd,Y,Eu)composite photocatalyst via hydrothermal method and applied it in photocatalytic oxidation of rhodamine B under visible light irradiation.The structure,morphology,and optical properties of the synthesized composite were investigated via XRD,XPS,TEM,and UV-vis et.al.Result indicates that AgBr/LnVO4(Ln=Gd,Y,Eu)composite is actually Ag/AgBr/XVO4(Ln=Gd.Y.Eu)system during photocatalytic process.The ternary system shows excellent photocatalytic activity.Under visible light irradiation for 12 min,more than 80%of RhB was degraded in the help of the AgBr/LnVO4(Ln=Gd,Y,Eu)photocatalyst.The degradation rate is is 2.8 to 8 times as much as that of pure AgBr.The high photoactivity can be ascribed to the synergetic effect of Ag,AgBr and LnVO4(Ln=Gd?Y?Eu)nanoparticle in separation of electron-hole pairs.