title: On the origin of the visible-light activity of titanium dioxide doped with carbonate species.
abstract: Plane-wave-based pseudopotential density functional theory (DFT) calculations are used to elucidate the origin of the high photocatalytic efficiency of carbonate-doped TiO(2). Two geometrically possible doping positions are considered, including interstitial and substitutional carbon atoms on Ti sites. From the optical absorption properties calculations, we believe that the formation of carbonates after doping with interstitial carbon atoms is crucial, whereas the contribution from the cationic doping on Ti sites is negligible. The carbonate species doped TiO(2) exhibits excellent absorption in the visible-light region of 400-800 nm, in good agreement with experimental observations. Electronic structure analysis shows that the carbonate species introduce an impurity state from Ti 3d below the conduction band. Excitations from the impurity state to the conduction band may be responsible for the high visible-light activity of the carbon doped TiO(2) materials.
authors.affiliation: Institute of Computational Science and Engineering, Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, 266071, China. tfh@qdu.edu.cn
authors.forename: Fenghui
authors.initials: F
authors.lastname: Tian
authors.forename: Chengbu
authors.initials: C
authors.lastname: Liu
authors.forename: Dongju
authors.initials: D
authors.lastname: Zhang
authors.forename: Aiping
authors.initials: A
authors.lastname: Fu
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Duan
authors.forename: Shuping
authors.initials: S
authors.lastname: Yuan
authors.forename: Jimmy C
authors.initials: JC
authors.lastname: Yu