Preparation and Photocatalysis Activity of Gd3+ and Eu3+ Co-doped TiO2 Powder

Pure TiO₂ and Gd³⁺/Eu³⁺ co-doped TiO₂ composite nano-particle were prepared by sol-gel method and characterized by the techniques such as XRD and SEM. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The mechanisms of effects of Gd³⁺ and Eu³⁺ co-doped on the photocatalytic activity of the TiO₂ composite nano-particles were also discussed. The results show that Gd³⁺ and Eu³⁺ co-doped can significantly enhance the photocatalytic activity of TiO₂ nano-particles. The co-doped Gd³⁺ and Eu³⁺ shows a synergistic effect for photocatalytic activity of TiO₂ nano-particles, can inhibt the phase transformation from anatase to rutile and decrease the diameter of TiO₂ nano-particles. The matrix distortion of TiO₂ nano-particles increases when the Gd³⁺ and Eu³⁺ have co-doped and the blue-shift of the absorption profile are clearly observed. When the co-doped amounts for Gd³⁺ and Eu³⁺ are 0.4% and 0.2%, the mass percent of rutile phase is 4.5%, the photocatalytic activity of TiO₂ can be improved sffectively, and its degradation rate reaches 96.51%.