N掺杂锐钛矿二氧化钛光响应红移的模拟计算  

Simulating Calculation of Light Responding Red-Shift of Anatase Titanium Dioxide Doped with N

作　　者：潘湛昌[1] 彭康华[1] 张环华[1] 肖楚民[1] 魏志钢[1] 

机构地区：[1]广东工业大学轻工化工学院,广东广州510006

出　　处：《化学世界》2008年第3期141-143,153,共4页Chemical World

基　　金：广东省科技计划资助项目(2004B10301010;2006B36702004)

摘　　要：利用密度泛函理论(DFT),采用平面波超软赝势方法,模拟计算了掺N锐钛矿相TiO2对能隙、Fermi能级、态密度的影响,以探讨其可见光活性的机理。计算结果表明:表面HOMO和LUMO分别主要由Ti的3d轨道和O、N的2p轨道构成,掺杂出现的N2S态增加了N掺杂的稳定性。并发现N掺杂从两个方面使TiO2材料的带隙变窄:一为N掺杂使Fermi能级移入价带,使带隙变窄;二为在价带的上方引入了独立的能级,在导带下方引入一个宽为0.9 eV左右的能带,这两个掺杂能级使其禁带减小。With the density functional theory（DFT）, the band gap, Fermi level, density of states of TiO2 doped with N were simulated by using the plane wave pseudo potentials （PWPP） for discussing the mechanism of visible-light photocatalytic activity. The calculation showed that the HOMO and the LUMO are mainly composed of the 3d orbits of Ti and the 2p orbits of O and N. Stability of TiO2 are enhanced by 2s orbits of N which is newly arisen after doping. The band gap of N-doped TiO2 is narrowed. The Fermi level is displaced into the valence band to make the band gap narrowed. On the other hand, an independent energy band is introduced above the valence band and an energy band with the breadth of 0. 9 eV is introduced under the conduction band（CB） to make the band gap narrowed too.

关 键 词：二氧化钛 N掺杂 可见光 光催化 密度泛函 

分 类 号：O643[理学—物理化学]