Synthesis and photocatalytic property of a mixture of anatase and rutile TiO2 doped with Fe by mechanical alloying process

The nanocrystalline Fe-doped mixture TiO2 powders which consisted of anatase and rutile phase were synthesized by mechanical alloying (MA). The mixtures TiO2 powders had small particle size in the range of 10–15 nm with spherical shape. Photocatalytic property of a mixture of anatase and rutile TiO2 doped with Fe was investigated. In the PL and UV-DRS data, Fe-doped mixture TiO2 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 TiO2 powder had the highest decomposition rate as compared to P-25, pure anatase and pure rutile powders. The band gap of Fe-doping TiO2 powder was decreased because of trapping level near the valance band or conduction band. The recombination of generated E–H pairs of mixture TiO2 powder was decreased due to the difference in Fermi levels of anatase and rutile.