α-PbO2型TiO2电子结构的第一性原理计算

On the basis of first-principle calculations, the cell parameters and electronic structure of α-PbO₂-type TiO₂ were calculated by using the plane-wave ultra-soft pseudo-potential method in line with the density functional theory (DFT) and with the generalized gradient approximation (GGA). The optimized cell parameters were in good agreement with related experimental data. Electronic structure analysis revealed that α-PbO₂-type TiO₂ was an indirect wide-band semiconductor with a band gap of 2.47 eV, lager than the anatase TiO₂ band gap, which may be caused by lower crystal symmetry, the average longer Ti-O band length and the weaker extent of mixing of the Ti_3d and O_2p orbits of high-pressure orthorhombic α-PbO₂-type TiO₂. It was theoretically suggested that photocatalytic effect of α-PbO₂-type TiO₂ was not as good as that of anatase TiO₂.