过渡金属掺杂锐钛矿TiO2(101)表面的改性  

Modification of the photocatalytic properties of anatase TiO_2(101) surface by doping transition metals

作　　者：苏巧智 韩清珍[2] 高锦花[1,2] 温浩[2] 江兆潭[1] 

机构地区：[1]北京理工大学物理学院,北京100081 [2]中国科学院过程工程研究所,多相复杂系统国家重点实验室,北京100190

出　　处：《物理学报》2017年第6期214-222,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11504374,11274040);中国科学院介尺度研究中心创新基金(批准号:COM2015A001)资助的课题~~

摘　　要：采用密度泛函理论的平面波超软赝势方法,对过渡金属Fe,Ni,Pd,Pt,Cu,Ag和Au的中性原子在锐钛矿TiO_2(101)面上的掺杂改性开展了系统深入的理论研究.通过比较分析锐钛矿TiO_2(101)面掺杂前后的几何结构、电子结构和光学性质等,揭示了宏观催化活性与电子结构、光电子特性之间的关联.结果表明:过渡金属掺杂能减小禁带宽度或引入杂质能级,从而提高TiO_2(101)面的可见光响应;杂质能级通常位于禁带内,这主要是由过渡金属原子的d电子态贡献形成的;不同过渡金属掺杂的TiO_2(101)面具有不同的光催化性能,这与掺杂后的禁带宽度、费米能级位置、杂质能级的形成位置以及过渡金属原子的最外层电子排布等有关.本研究为TiO_2光催化剂结构设计与改性提供了指导性参考,并有利于加深人们对其他材料的过渡金属掺杂的理解.Exploring new types of photocatalysts and modifying the photocatalytic activity have attracted more and more extensive attention in many research fields.Anatase Ti O2,a promising photocatalyst widely studied,can only absorb the ultraviolet light and thus only make little use of the power in visible light.Therefore,it is an urgent task to make theoretical and experimental investigations on the photocatalytic mechanism in anatase Ti O2 and then improve its visible light response so as to utilize more visible light.Now,in the present paper,we carry out a systematic theoretical investigation on modifying the photocatalytic properties of the anatase Ti O2（101） surface via doping transition metal neutral atoms such as Fe,Ni,Pd,Pt,Cu,Ag,and Au by using the plane wave ultrasoft pseudopotential method of the density functional theory.The dependence of the macroscopic catalytic activity on electronic structure and optoelectronic property is uncovered by making a comparative analysis of the geometric structures,the electronic structures,and the optical properties of the undoped and doped anatase Ti O2（101） surfaces.Our numerical results show that doping certain transition metals can suppress the band gap or induce extra impurity energy levels,which is beneficial to improving the visible light response of the Ti O2（101） surface in different ways.In most cases,the new impurity energy levels will appear in the original band gap,which comes from the contribution of the d electronic states in the transition metal atoms.Moreover,the photocatalytic activity of the Ti O2（101） surface can be changed differently by doping different transition metal atoms,which is closely dependent on the bandgap width,Fermi energy,the impurity energy level,and the electron configuration of the outermost shell of the dopants.This research should be an instructive reference for designing Ti O2（101） photocatalyst and improving its capability,and also helpful for understanding doping transition metal atoms in other materials.

关 键 词：锐钛矿TiO2(101)面 过渡金属掺杂 电子结构 光学性质 

分 类 号：O469[理学—凝聚态物理]