气相火焰燃烧合成锌掺杂TiO2纳米晶的光催化性能

以四氯化钛和乙酰丙酮锌为原料，采用气相火焰燃烧合成锌掺杂TiO2纳米晶，利用XRD, XPS和ICP-AES研究了纳米晶结构，考察了锌掺杂TiO2纳米晶在紫外光辐照下催化降解罗丹明B(Rhodamine B)的活性，探讨了光催化机理. 研究结果表明，掺杂相锌主要分布在TiO2表相，并形成均匀分散的ZnO团簇；燃烧过程中锌掺杂对纳米TiO2的晶相组成及晶粒尺寸影响不大. 当掺杂量为0.21%(mol)时，样品具有最高的光催化活性. 光催化机理分析表明，TiO2与ZnO不同的能带位置使光生载流子能够有效分离，改善了纳米TiO2光催化活性.

Photocatalytic Activity of Zn-doped TiO2 Nanocrystals Synthesized by Diffusion Flame Combustion

Zinc-doped TiO2 nanocrystals were synthesized by diffusion flame method with titanium tetrachloride and zinc aceetylacetonate as raw materials, and their structures were characterized by XRD, ICP-AES and XPS. The catalytic activity of Zn-doped TiO2 nanocrystals on photodegradation of Rhodamine B was investigated under UV light irradiation and the mechanism was elaborated to demonstrate the improved photocatalytic activity of Zn-doped TiO2 nanocrystals. It is found that dopant Zn2+ ions are mostly located on the surface of TiO2 nanoparticle, and small ZnO nuclei dispersing randomly on the anatase TiO2 surface form, which has less effect on the crystalline phase and particle size. The best photocatalytic activity of 0.21%(mol) Zn-doped TiO2 nanoparticles is attributed to the enhancement of electron and hole segregation because of the difference in the energy band positions of TiO2 and ZnO.