Abstract: A magnetic TiO₂ photocatalyst of Fe₃O₄ magnetic core was prepared with a sol-gel method, and its photocatalytic activity was evaluated by the photo degradation of methyl orange aquous solution. The effects of Fe doping amount, calcination temperature and calcination time on the photocatalytic activity were investigated. The results showed that the optimal preparation conditions were of 5% Fe doping amount, 450 ℃ calcination temperature and 2 h calcination time. The prepared catalyst was characterized by thermo-gravimetric differential thermal analysis (TG-DTA), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis) and transmission electron microscope (TEM), and the results showed that prepared catalyst had a core-shell structure with the coating of TiO₂ on the surface of magnetic core. The original magnetic Fe₃O₄ core was oxidized by high temperature calcination .There was a red shift in the absorption band edge of prepared catalyst, its absorption intensity in the visible light region increased slightly, and the average particle size of prepared catalyst was 20 nm.

Key words: sol-gel method, magnetic catalyst, photocatalytic activity