Al掺杂对锐钛矿型TiO_2光催化性能影响的研究

A study on the photocatalytic activity of Al doped anatase TiO_2

采用平面波赝势(PWPP)方法进行密度泛函(DFT)计算,研究了Al掺杂对锐钛矿晶体能带、态密度的影响.分析发现掺杂后Al原子3s和3p轨道上的电子虽然对晶体的价带和导带贡献不大,却诱使导带发生较大程度下移,禁带宽度减小,理论预测可以发生红移.采用低温燃烧合成法制备了Al掺杂锐钛矿型纳米TiO2,紫外-可见吸收光谱检测和甲基橙降解实验证明,Al掺杂TiO2光吸收强度增强,吸收带边界发生红移;光催化性能较纯TiO2有所改善.理论计算结果与实验结果相符.

Anatase TiO2 super cell are formated and geometry optimized. The band structure and the density of states of anatase TiO2 doped by AI have been simulated with relativistic density functional theory （DFY） and plane wave pseudo potentials （PWPP）. The results show that the electrons of AI atom on the 3s and 3d orbits make the entire conduction band move to the Fermi level, which leads to the narrowing of band gap and the red shift electrophoresis. Nanosized AI doped anatase TiO2 was synthesized by low temperature combustion process. 1＇he UV-Visible absorption spectra and the photodegradation test of methyl orange show that the photocatalytic activity of Al doped anatase TiO2 is better than the pure TiO2, which is identical to the theoretical results.