低量Gd^3＋／Fe^3＋共掺杂TiO2制备及催化活性

利用溶胶-凝胶法在煅烧温度540℃制备了纯的和不同Gd^3＋／^3＋共掺杂的TiO2纳米粉体，并用XRD技术对样品进行了表征。研究了Gd^3＋／Fe^3＋共杂量对样品相结构、晶粒尺寸和光催化降解亚甲基蓝的活性的影响，利用相结构与纳米TiO2光催化活性关系探讨了Gd^2＋／Fe^3＋共掺杂对纳米TiO2的光催化活性。结果表明，与纯TiO2相比，适量共掺杂Gd^3＋／Fe^3＋可以显著提高其光催化活性。当Gd^3＋／Fe^3＋共掺杂量为0．04％／0．04％，Ti02纳米粉体的光催化活性最佳，降解率为89．96％，其金红石相含量为32％，平均晶粒粒径为30nm，Gd^3＋／Fe^3＋共掺杂强烈地抑制TiO2由锐钛矿相向金红石相的转变，减小晶粒尺寸这两方面均有利于提高光催化活性。

Preparation and Photocatalytic Activities of Low Amout Gd3+and Fe3+Co-doped TiO2 Composite Nano-Powders

Pure and Gd^3＋/Fe^3＋ Co -doped TiO2 namo -particles with low amounts were prepared at 540℃ for 4h by solgel method using Ti（OC4H9）4 as precursors and characterized with XRD. The effects of the amount of Gd^3＋/Fe^3＋ Co -doped on the photocatalytic activity for photocatalytic degradation of methylene blue in solution , phase structure and crystallite size of the namopowders were investigated. The mechanism of the effects of Gd^3＋/ Fe^3＋ Co - doped on the photocatalytic activity of TiO2 namo - particles was discussed in relation ship between the crystal structure and its photocatalytic activity. The results show that Gd^3＋/Fe^3＋ （0.04% /0.04% ） Co - doped can significantly enhance the photocatalytic activity of TiO2 nomoparticles, the mass prcent of rutile phase was 32%, its degradation percent is 89.96% and crystalline sizes is about 30 nm. The presence of Gd^3＋/Fe^3＋ Co -doped in TiO2 can inhibit the phase transformation from anatase to rutile and suppress the growth of TiO2 grains, which resulted in increase in the photoactivity.