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采用溶胶-凝胶法制备了纯TiO2,1%Sm3＋或2%Gd3＋单掺杂和1%Sm3＋/2%Gd3＋共掺杂TiO2复合粉体,采用XRD和SEM/EDAX等技术进行表征。以对亚甲基蓝的光催化降解为目标反应,评价了TiO2复合粉体的光催化活性,探讨了Sm3＋/Gd3＋共掺杂、亚甲基蓝初始浓度和粉体投加量对TiO2粉体光催化活性的影响机制。结果表明,Sm3＋/Gd3＋共掺杂可以显著提高TiO2粉体的光催化活性;Sm3＋/Gd3＋共掺杂在TiO2粉体中产生协同作用,抑制了TiO2由锐钛矿相向金红石相转变,使TiO2粒径尺寸减小,增大了TiO2的晶格畸变。当亚甲基蓝初始浓度为4mg/L和粉体投加量为2g/L时,TiO2复合粉体的光催化活性最高,对亚甲基蓝光催化降解率达99.71%;降解亚甲基蓝反应符合Langmuir-Hinshelwood动力学方程。

Pure TiO2,Sm3+ or Gd3+ single-doped and Sm3+/Gd3+ co-doped TiO2 composite nano-particle were prepared by sol-gel method and characterized by the techniques such as XRD and SEM/EDAX.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 Sm3+/Gd3+ co-doped,the initial concentration of methylene blue in water and the concentration of TiO2 in solution on the photocatalytic activity of the TiO2 composite nano-particles were also discussed.The results showed that Sm3+/Gd3+ co-doped can significantly enhance the photocatalytic activity of TiO2 nano-particles.The co-doped of Sm3+/Gd3+ showed a synergistic effect for photocatalytic activity of TiO2 nano-particles,could inhibit the phase transformation from anatase to rutile and decrease the diameter of TiO2 nano-particles,and the matrix distortion of TiO2 nano-particles increased when the Sm3+/Gd3+ have co-doped.When the co-doped amounts for Sm3+/Gd3+ were 0.1% and 0.2%,the initial concentration of methylene blue was 4mg/L,and the concentration of TiO2 was 2g/L the photocatalytic activity of TiO2 could be markedly improved,and its degradation rate reached 99.71%.Kinetic equation of photocatalytic degradation of methylene blue was corresponded to Langmuir-Hinshelwood equation.