Synthesis and photocatalytic property of a mixture of anatase and rutile TiO 2 doped with Fe by mechanical alloying process

Abstract

The nanocrystalline Fe-doped mixture TiO 2 powders which consisted of anatase and rutile phase were synthesized by mechanical alloying (MA). The mixtures TiO 2 powders had small particle size in the range of 10–15 nm with spherical shape. Photocatalytic property of a mixture of anatase and rutile TiO 2 doped with Fe was investigated. In the PL and UV-DRS data, Fe-doped mixture TiO 2 showed the photo-absorption threshold shifted to the high wavelength (442 nm; 2.81 eV), suggesting a decrease in the band gap, and the decreased intensity of PL indicating the decrease of recombination of E–H pairs (e − and h +). In the decomposition of 4-chlorophenol, the Fe 2 wt% doped mixture TiO 2 powder had the highest decomposition rate as compared to P-25, pure anatase and pure rutile powders. The band gap of Fe-doping TiO 2 powder was decreased because of trapping level near the valance band or conduction band. The recombination of generated E–H pairs of mixture TiO 2 powder was decreased due to the difference in Fermi levels of anatase and rutile.