Si，Ge，Zr和Sn掺杂SrTiO3的电子结构和光催化性能第一性原理研究

使用QUANTUM ESPRESSO(QE)软件包实现的密度泛函理论研究了Si, Ge, Zr和Sn掺杂SrTiO₃的结构，电子结构和光催化性能.使用广义梯度近似(GGA)获得SrTiO₃的晶格常数与先前的实验数据非常一致.同时，获得了SrTi_0.875X_0.125O₃(X=Si, Ge, Zr, Sn)四种掺杂体系的晶格常数. SrTiO₃和SrTi_0.875X_0.125O₃(X=Si, Ge, Zr, Sn)四种掺杂的带隙值分别1.853 eV、1.849 eV、1.916 eV、1.895 eV和1.925 eV.在研究五种SrTiO₃体系的光催化性能时，采用剪刀算符对五种SrTiO₃体系的带隙值进行修正.计算本征SrTiO₃和SrTi_0.875X_0.125O₃

First principles study on electronic structure and photocatalytic performance of Si, Ge, Zr and Sn doped SrTiO3

In this paper, electronic structure and photocatalytic performance of Si, Ge, Zr and Sn doped SrTiO3 were studied using density functional theory realized by QUANTUM ESPRESSO (QE) software package. The lattice constants of SrTiO3 obtained by using the generalized gradient approximation (GGA) are very consistent with the previous experimental data. At the same time, the lattice constants of SrTi0.875X0.125O3 (X=Si, Ge, Zr, Sn) doped systems were obtained. The band gap values of SrTiO3 and SrTi0.875X0.125O3 (X=Si, Ge, Zr, Sn) are 1.827 eV, 1.778 eV, 1.878 eV, 1.917 eV and 1.936 eV, respectively. The band gaps of the five systems increase with the increase of molecular weight. When studying the photocatalytic performance of five SrTiO3 systems, the band gap values of the five SrTiO3 systems were modified by using the scissors operator. The reduction potential (ECB) of the conduction band edge of the four intrinsic SrTiO3 and SrTi0.875X0.125O3 (X=Si, Ge, Zr, Sn) doping systems were calculated to be -0.782 eV, -0.714 eV, -0.770 eV, -0.824 eV and -0.810 eV, respectively. The oxidation potential (EVB) of the valence band edge corresponding to five SrTiO3 systems was calculated as 2.418 eV, 2.437 eV, 2.481 eV, 2.466 eV and 2.499 eV, respectively. From the perspective of redox properties, the redox properties of the three SrTi0.875X0.125O3 (X=Ge, Zr, Sn) doping systems are improved compared with the intrinsic SrTiO3, and the redox properties of SrTi0.875X0.125O3 are reduced compared with the intrinsic SrTiO3. The relative positions of the band edges of the five SrTiO3 systems can meet the process of water splitting to generate H2 and O2.