First-principle study on the magnetic and optical properties of TiO 2 doped with different valence Fe

The effect of Fe doping with different valence states on the magnetic and the optical properties of rutile TiO 2 has not been recognized. This paper adopts the First-principles generalized gradient approximation + U (GGA + U) method. The band gaps of Ti 14 Fe 2 3+ O 32 and Ti 14 Fe 2 2+ O 32 systems are narrowed compared with those of pure rutile TiO 2, and the absorption spectra red-shifted. Holes or electron capture positions are introduced to reduce the probability of the hole–electron pair recombination. The Ti 14 Fe 2 3+ O 32 system has narrower band gap, more remarkable red- shift in the absorption spectrum, slower electron and hole recombination, faster separation, and better photocatalytic performance than the Ti 14 Fe 2 2+ O 32 system. The semimetallization is performed. P -type dilute magnetic semiconductor with semimetallization is advantageous as a hole injection source. Moreover, the ferromagnetic mechanism can be achieved at room temperature. The Ti 14 Fe 2 3+ O 32 system has certain reference value for designing and preparing novel photocatalysts or dilute magnetic semiconductors.