Ag^＋／Fe^3＋共掺杂纳米TiO2薄膜光催化性研究

Influence of Nano TiO2 by Ag^＋/Fe^3＋ Co-doping on Photocatalytic Degradation to Methyl Orange

用溶胶-凝胶法制备了Ag^＋／Fe^3＋复合掺杂的纳米TiO2薄膜，以甲基橙为光催化反应模型化合物，考察了复合掺杂光催化剂的活性。Ag^＋、Fe^3＋的掺入量分别为ωAg^＋=0．043％、ωFe^3＋=0．1％，且同时掺入TiO2光催化时具有最佳的光催化效率。并通过XRD、AFM、UV—Vis对复合掺杂薄膜进行了表征。结果表明，金属共掺杂可以促进纳米TiO2由锐钛矿向金红石相转化，平均晶径约为30nm左右；Fe^3＋掺入可能以替代的方式占据TiO2晶格中Ti^4＋的位置，并在TiO2禁带中产生掺杂能级，使吸收边红移，并在可见光区有极低的透过率。Ag^＋的掺入在光催化过程中有效地抑制光生电子与空穴的复合，提高掺杂TiO2的光催化效率。

Ag^＋/Fe^3＋ -doped nano TiO2 films were prepared by a sol-gel process. As a model reaction, the photocatalytic degradation of methyl orange was investigated. Optimal doping amounts for Ag^＋ and Fe^3＋ are ωAg^＋= 0. 043%, Ze, ωFe^3＋ = 0.1%, respectively. Furthermore, the co-doping of them shows a good photocatalytic effect. The nanoTiO2 films were investigated by means of XRD, AFM, and UV-Vis. The results show that metal dopant promotes the transformation of TiO2 from anatase to ruffle and the average crystal size was about 30 nm. The doped Fe^3＋ ions maybe mainly penetrate into the lattice of TiO2 and substitute the Ti^4＋ ions of TiO2, And then a doping energy level emerges among the gap of TiO2, which help to increase the visible light absorption of TiO2, and have a lower transmittance in the visible light gap, Doped Ag^＋ inhibited recombination of photoinduced electrons and holes, and enhanced the activities of nano TiO2 photocatalysts.