La(Ⅲ)掺杂TiO2密度泛函理论的研究

A study on La(Ⅲ) doped anatase titanium dioxide by density function theory

为了研究La(Ⅲ)掺杂对TiO_2光催化活性的影响,采用基于密度泛函理论(DFT)框架下的第一性原理平面波赝势(PWPP)法,模拟计算La(Ⅲ)掺杂锐钛矿TiO_2,讨论它的晶体结构、能隙、态密度等。结果表明La(Ⅲ)掺杂锐钛矿TiO_2晶体后,La(Ⅲ)的5d轨道与Ti(Ⅳ)的3d轨道一同构成导带,使禁带宽度(Eg)变小,TiO_2的吸收带红移,从而有助于TiO_2的光催化活性提高。

Using density function theory （DFT）, the geometry, band structure and electronic density states of La （Ⅲ） doped anatase Titanium Dioxide （La （Ⅲ）/TiO2 ） have been studied at plane wave ultra-soft pseudo-Potential （PWPP） in this paper. It shows that the 5d orbital of La （Ⅲ） inserts to the conduction band and interacts with 3d orbital of Ti（Ⅳ）, which leads to the narrowing of band gap in La（Ⅲ）/TiO2. It may lead us to the conclusion that there should be a red shift of the absorption band to enhance the photocatalytic activity of TiO2 with the adulteration of La（Ⅲ）.