Pt掺杂锐钛矿型TiO_2电子结构和光学性质第一性原理研究

First-Principles Study of Electronic Structure and Optical Properties of Pt-doped Anatase TiO_2

为了研究Pt掺杂对锐钛矿型TiO2电子结构和光学性质的影响,本文采用基于密度泛函理论的平面波超软赝势方法,对未掺杂和Pt掺杂锐钛矿型TiO2的电子结构和光学性质做第一性原理计算。得到了掺杂前后的晶格结构常数、结合能电子态密度分布、能带结构、介电函数虚部、光吸收系数等性质,定性地分析了掺杂前后能带结构和光学性质的变化。研究结果表明,Pt掺杂锐钛矿型TiO2带隙中能产生新的能带,而且能带位置明显下移,掺杂后不但能使TiO2的吸收带产生红移,而且在可见光区具有较大的吸收系数,表现出较高的光催化活性,理论与实验基本吻合。

In order to investigate the effect of Pt-doped on the electronic structure and optical proper- ties of anatase TiO2, we have carried out the First-Principle calculations based on the plane-wave ultra soft pseudo potential method of density-functional theory for the Electronic Structure and Optical Properties of Undoped and Pt-doped anatase TiO2. Cell parameters, partial density of states, band structures,the imaginary part of dielectric function and the optical absorption of undoped and Pt-doped anatase TiO2 have been calculated, furthermore, we have analyzed the changes of band structures and optical properties after Pt-doped. It is found that there are some new bands in the band gap for Pt-doped TiO2, and the band potentials of Pt-doped TiO2 shift downwards obviously, It is not only the Red-shift will happen, but also the optical absorption coefficient become larger in visible light, which shows that it has a stronger photocatalytic activity after Pt-doped, The experimental phenomena also approve the result.