第一性原理研究Ni、V、Zr、N、P、S单掺杂及其共掺杂锐钛矿物相TiO_2的电子结构和吸收光谱

First-principles calculations of the electronic structures and adsorption spectra of Ni,V,Zr,N,P,S-doped and co-doped anatase TiO_2

采用基于密度泛函理论(density functional theory,DFT)的Castep(MS 5.5)软件包进行计算,计算方法为广义梯度近似(generalized gradient approximation,GGA)下的Predew-Burke-Ernzerhof交换关联泛函和投影缀加平面波方法,构建2×2×1锐钛矿相二氧化钛单掺杂Ni、V、Zr、W等金属原子及N、P、S等非金属原子的晶胞模型,对掺杂锐钛矿相二氧化钛的能带结构、态密度和吸收光谱进行了计算.计算结果表明:Ni、V、Zr、W、P、N、S单掺杂二氧化钛的带隙宽度,除了W元素,其它掺杂元素都使带隙变窄,吸收光谱发生一定程度的红移.同时计算结果也表明,在金属和非金属共掺杂的作用下,由于共掺杂元素的引入,均使得带隙降低,其中P-V和S-Ni共掺杂的带隙最小,光学性质显示S-Ni共掺杂吸收边带最宽,对可见光的利用率最高,理论上S-Ni共掺杂锐钛矿二氧化钛具有良好的光致阴极保护效果.

The band structure,density of states and the absorption spectra of Ni,V,Zr,N,P,S-doped anatase TiO2 have been studied by first-principles calculation based on DFT（ density functional theory） using MS5. 5 software with the method of GGA（ generalized gradient approximation）. The calculation result shows that the band gap width of these elements mentioned above doped has been narrowed. And the absorption spectra occurs to a certain degree of redshift. Besides,the band gap has also reduced under the influence of co-doping of metal atoms and nonmetallic atoms. It can be easily seen that the band gap of P-V and S-Ni are smallest.In addition,it is concluded that S-Ni co-doped has the widest absorption band and the highest utilization rate of visible light in optical properties tests. Hence,S-Ni co-doped anatase TiO2 has a better effect on cathodic protection theoretically.