S掺杂TiO_2的第一性原理分析及光学性质研究  

First-principles Analysis and Optical Properties of S-doped TiO_2

作　　者：邢锦娟[1,2] 张未尘 刘娇[1] 钱建华[1] 唐克[1] 

机构地区：[1]渤海大学,辽宁省功能化合物合成与应用重点实验室,辽宁锦州121013 [2]锦州市科齐科技有限公司,辽宁锦州121013

出　　处：《辽宁化工》2016年第12期1482-1485,共4页Liaoning Chemical Industry

基　　金：辽宁省教育厅创新团队项目[LT2015001];辽宁省教育厅第三批特聘教授支持计划[2014-323];国家自然科学基金项目[21606023]

摘　　要：基于密度泛函理论的从头算方法,以锐钛矿TiO_2为研究对象,利用计算机模拟技术分析了S掺杂TiO_2的电子结构。用广义梯度近似法对优化后的理论模型进行单电子能量计算,到完整的和掺S的TiO_2晶体能带、总态密度(TDOS)以及分态密度(PDOS)图。分析了光学性质中的介电函数、吸收系数值。计算结果表明:TiO_2经掺杂后带隙变窄,掺杂后体系的介电函数向低能方向移动,具有优异的介电性能,掺杂体系的吸收边红移。S原子取代TiO_2中的O原子后,价带上方的杂质能级峰强较大,电子在该杂质能级上存在几率较大。在可见光催化实验中,可形成光生电子-空穴的捕获势阱,减小电子与空穴的复合几率,进而提高光催化效果。The anatase TiO2 was studied by ab initio calculation method based on density functional theory. The electronic structure of S doped TiO2 was analyzed by the computer simulation technology, which was based on the ab initio calculation method. The single electron energy, the energy band, the total density of states （TDOS） and the density of states （PDOS） of the TiO2 and S doped TiO2 were calculated with the generalized gradient approximation method. Then the dielectric function and absorption coefficient in the optical properties were analyzed. The calculation results show that the TiO2 band gap becomes narrow after doping, the dielectric function of the doped system moves toward the low energy direction, and has excellent dielectric properties, and red shift of the absorption edge of the doped system appears. After O atoms of TiO2 are replaced by S, impurity levels peak intensity above the valence band is larger, existence probability of electron on the impurity energy level is large. In the visible light photocatalytic experiment, the trapping potential well of the photo generated electron hole can be formed, and the recombination probability of the electron and the hole is reduced, and the photocatalytic effect can be improved.

关 键 词：密度泛函理论 TIO2 电子结构 光催化 

分 类 号：O69[理学—化学]