Kuo Ming-Yu, Chen Cheng-Lung, Hua Chih-Yu, Yang Hsiao-Ching, Shen Pouyan
Institute of Materials Science and Engineering and Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, Republic of China.
J Phys Chem B. 2005 May 12;109(18):8693-700. doi: 10.1021/jp0510903.
Structural parameters and electronic band gaps of dense TiO(2) polymorphs, i.e., alpha-PbO(2), baddeleyite, fluorite, and cotunnite types of structures, were calculated using a first-principles density functional method with local-density approximation. The ambient phases, i.e., rutile and anatase, with known theoretical and experimental data were used to ensure the validity of the calculations. The fluorite-type TiO(2) turned out to have the narrowest band gap, 1.08 or 2.18 eV after applying a very approximate band gap correction, due to highly symmetrical TiO(8) polyhedra with Ti(3d) and O(2p) orbitals in the most mixed state. Ti with eight coordinated oxygens, as feasible under high pressure or residual stress, may have potential applications as a visible-light-responsive photocatalyst.
使用具有局域密度近似的第一性原理密度泛函方法，计算了致密TiO₂多晶型物（即α-PbO₂、斜锆石、萤石和方钍石型结构）的结构参数和电子带隙。利用具有已知理论和实验数据的常温相（即金红石和锐钛矿）来确保计算的有效性。结果表明，萤石型TiO₂具有最窄的带隙，在应用非常近似的带隙校正后为1.08或2.18 eV，这是由于具有处于最混合状态的Ti(3d)和O(2p)轨道的高度对称TiO₈多面体。在高压或残余应力下可行的具有八个配位氧的Ti，可能作为可见光响应光催化剂具有潜在应用。
