Abstract: The mechanism of photocatalytic degradation of TiO 2 was explored by adding hole inhibitors ( EDTA) , free radical inhibitors ( t-BuOH ) in the process of degradation of methyl orange .From our experiment can be found that the main oxidative species is holes in the photocatalytic process could be detected through the trapping experiments of radicals and holes .Because conductive polymer PAN will be able to separate electron-hole timely, reducing the chance of electron-hole recombination , the photocatalytic activity of the composite particle is significantly higher than that of pure TiO 2 .

Key words: The mechanism of photocatalytic degradation of TiO 2 was explored by adding hole inhibitors ( EDTA) , free radical inhibitors ( t-BuOH ) in the process of degradation of methyl orange .From our experiment can be found that the main oxidative species is holes in the photocatalytic process could be detected through the trapping experiments of radicals and holes .Because conductive polymer PAN will be able to separate electron-hole timely, reducing the chance of electron-hole recombination , the photocatalytic activity of the composite particle is significantly higher than that of pure TiO 2 .