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.

Graphical AbstractThe crystal structure of anatase TiO2 (a), Fe doped TiO2 (b) and FeTiO3 (c). Dull gray, red and purple spheres represent Ti, O and Fe atoms, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► 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). ► The FeTiO3 has the strongest absorption due to the existence of the covalence bond character of FeTiO3 between Ti, Fe and O atoms. ► The first principle calculation further confirms the red shift of the absorption edges of FeTiO3.