表面活性剂对材料微结构与光催化性能的调控

Regulation of Surfactant on the Microstructure and Photocatalytic Property

摘要:

为探讨不同性质表面活性剂对材料结构的影响，以4种常用的表面活性剂为模板，在相同的条件下制备出性能各异的铝掺杂二氧化钛（Al-TiO2）粉体材料。并对材料的微结构和组成进行了表征与分析。结果表明，表面活性剂疏水基团所含碳原子数与Al-TiO2粉体的微晶尺寸呈负相关性，与晶格应力呈正相关性。表面活性剂诱导Al3 进入TiO2晶格的质量分数越大，晶格应力越大。Al-TiO2粉体材料的可见光降解吡啶的性能主要是由表面活性剂本身特定的分子结构及其所导致的氧空位浓度大小来决定，而不是能带间隙的宽窄来决定。阴离子表面活性剂对材料的微结构有很大的调控作用，其中SDS为最大；阳离子表面活性剂CTAB次之，两性表面活性剂对材料性能的调控没有优异表现。

Abstract:

To investigate the effect of various surfactant in the microstructure, using four surfactants as templates, Al doped titanium dioxide (Al-TiO2) powder with various properties were prepared by the same condition. And the materials microstuctures were characterized and analyzed. The results showed that carbon atomicity of hydrophobic groups in surfactant is negative to the crystallite size of Al-TiO2 powder and positive to the distorting stress. Moreover, the more the mass fraction that Al3 entered into TiO2 crystal lattice induced by the surfactant, the more the distorting stress produced by crystal lattice. Visible light degradation property of pyridine on the Al-TiO2 powder surface is mostly determined by the molecule structure of surfactant and thus the oxygen vacancy concentration induced by surfactant rather than the band gap width. In the controlling range of anion surfactant on the materials structure, SDS is stronger than that cation surfactant, but the ampholytic surfactant is poor.