Abstract: The iron doping titanium dioxide was prepared by solgel,step precipi tation,coprecipitation and immersion methods,respectively.The photocatalytic a ctivities of these prepared samples were evaluated in X3B dispersion irradiate d under UV.The experimental results showed that the immersion method,especially using the nano TiO2 as immersion matrix,greatly enhanced the photocatalytic acti vity.One fold enhancement in photocatalytic activity was observed in the case of the sample prepared by immersion doping method.This may be attributed to the na nosize effect,the irreversible hole trapper in nonsaturated bonding field of Fe3＋ and larger lattice strain.

Key words: Sol-gel, Hydrolysis, X-ray diffraction, Lattice strain, Photoca talysis