用扩散火焰燃烧合成Fe3+掺杂TiO2纳米晶的结构及紫外光催化性能

Structure and UV Photocatalytic Activity of Fe3+Doped TiO2Nanocrystals Synthesized by Diffusion Combustion Flames

摘要: 采用气相火焰燃烧合成Fe3+掺杂TiO2纳米晶，利用XRD、XPS、ICPAES和EPR等手段分析了物相结构，考察了Fe3+掺杂TiO2纳米晶在紫外光辐照下降解罗丹明B活性，探讨了紫外光催化机理。结果表明：Fe3+掺杂显著提高了TiO2纳米晶的光催化活性，Fe3+最佳掺杂摩尔分数为0.05％。Fe3+作为光生电子和空穴的双重浅势捕获陷阱，有效地分离了光生载流子，提高了光催化活性。但在TiO2体相中过多Fe3+富集将增加因多次捕获而造成的载流子复合，降低光催化活性。

Abstract: Fe3＋doped TiO2 nanoparicles were prepared by diffusion flame method. The prepared TiO2 were characterized by XRD, ICPAES, XPS and EPR. The activity of TiO2 nanocrystals on photodegradation of RhB was investigated under UV light irradiation and the mechanism was elaborated to demonstrate the improved photocatalysis activity of Fe3+doped TiO2 nanocrystals. The best photocatalysis activity of 0.05% Fe3+ doped TiO2 nanoparticles is attributed to the fact that Fe3+ on the near surface of TiO2 can be considered as both hole and electron traps and inhibit the charge pair recombination. However, high level Fe3+ doping in bulk TiO2 matrix would lead to charge pair recombination and undermine the photocatalytic activities of TiO2 nanoparticles.