Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (1  0 1) surface

Publication date: 15 November 2017 Source:Computational and Theoretical Chemistry, Volume 1120 Author(s): Dragan Toprek, Vasil Koteski, Jelena Belošević-Čavor, Valentin Ivanovski, Ana Umićević In this paper we investigated the effects of Fe -doping of the anatase TiO 2 (1 0 1) surface on the crystal structure, electronic and optical properties, and impurity formation energy by means of density functional theory (DFT). The calculations were performed by the SIESTA DFT code and were carried out by using Troullier-Martins pseudopotentials for the 12-electron valence configuration ( 3 s 2 3 p 6 3 d 2 4 s 2 ) of Ti atom, 6-electron valence configuration ( 2 s 2 2 p 4 ) of O atom and 8-electron valence configuration ( 3 d 6 4 s 2 ) of Fe atom. We used a double- ζ basis set including polarization functions. All calculations were spin-polarized. The mechanism of narrowing the band gap and increasing the photocatalytic activity in the visible light region, of the doped TiO 2 is discussed by investigating the density of state. The band gap decreases as the concentration of the dopant increases. The Partial Density of States (PDOS) is not the same in the case of spin-up state or spin-down state. Enhanced optical absorption, for light polarized in the z direction (parallel to the surface normal) is clearly observed for Fe doped as compared to the pure anatase TiO 2 and the optical absorption is found to increase with t...

Source: Computational and Theoretical Chemistry - October 27, 2017 Category: Chemistry Source Type: research