用扩散火焰燃烧合成Fe^3＋掺杂TiO2纳米晶的结构及紫外光催化性能

Structure and UV Photocatalytic Activity of Fe^(3+)-Doped TiO_2 Nanocrystals Synthesized by Diffusion Combustion Flames

采用气相火焰燃烧合成Fe3+掺杂TiO2纳米晶,利用XRD、XPSI、CP-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。

Fe^3＋-doped TiO2 nanoparicles were prepared by diffusion flame method. The prepared TiOz were characterized by XRD, ICP-AES, XPS and EPR. The activity of TiO2 nanocrystals on photodegradation of RhB was investigated under UV light irradiation and the mechanism was elaborated to demonstrate the improved photocatalysis activity of Fe^3＋-doped TiO2 nanocrystals. The best photocatalysis activity of 0.05 % Fe^3＋ doped TiO2 nanoparticles is attributed to the fact that Fe^3＋ on the near surface of TiO2 can be considered as both hole and electron traps and inhibit the charge pair recombination. However, high level Fe^3＋ doping in bulk TiO2 matrix would lead to charge pair recombination and undermine the photocatalytic activities of TiO2 nanoparticles.