LAUSR

Abstract The effect of Fe doping with different valence states on the magnetic and the optical properties of rutile TiO2 has not been recognized. This paper adopts the First-principles generalized gradient approximation + U (GGA + U) method. The band gaps of Ti14Fe23+O32 and Ti14Fe22+O32 systems are narrowed compared with those of pure rutile TiO2, and the absorption spectra red-shifted. Holes or electron capture positions are introduced to reduce the probability of the hole–electron pair recombination. The Ti14Fe23+O32 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 Ti14Fe22+O32 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 Ti14Fe23+O32 system has certain reference value for designing and preparing novel photocatalysts or dilute magnetic semiconductors.