Synergistic effect of Eu3+ and Si4+ co-doping on photocatalytic activity of titanium dioxide

Eu/Ti/Si composite photocatalysts were prepared by sol-gel-soaking process and characterized by XRD, FT-IR and EPR. It has been shown that the particle diameter of Eu/Ti/Si photocatalysts decreased, the crystal transformation of titania from anatase to rutile was prevented, and the incorporation of Si4+ into the matrix of the TiO2 was promoted owing to the co-doping of Si4+ and Eu3+. As a model reaction, the photocatalytic degradation of methyl orange was investigated. The adsorption constants of methyl orange over catalysts were evaluated and the adsorption mechanism was also discussed. Optimal doping amounts for Si4+ and Eu3+ are w(SiO2) = 39.06% and w(Eu) = 0.03% respectively, and the co-doping of them shows a synergistic effect for photocatalytic activity of titanium dioxide. Relation between photocatalytic activity and property of the photocatalyst was discuused.