Ab initio study of electronic structures and absorption properties of pure and Fe3+doped anatase TiO2

Using the first-principles calculations, the band structure, total and partial density of states (DOS) and absorption properties of anatase TiO2, Fe3+ doped TiO2 and FeTiO3 were calculated by a plane-wave pseudopotential method based on density functional theory (DFT). From the calculated results, the band gaps of anatase TiO2, Fe3+ doped TiO2 and FeTiO3 are about 2.4, 0.32 and 0.28 eV, respectively. The states of the valence bands and conduction bands of undoped and Fe3+ doped TiO2 with anatase structure were calculated. As shown in the absorption spectra, the FeTiO3 has the strongest absorption and the Fe–TiO2 has the weakest absorption. Effect of Fe3+ dopant on the absorption property of the anatase TiO2 is explained in detail based on the calculations using the first-principles. The Fe3+ doped anatase TiO2 could be a potential candidate for photocatalyst because of the absorption ability of visible light.