Preparation and Visible Light Photocatalytic Activity of Bimodal Mesoporous TiO2/I2 Composite Nanomaterials

An accessible, template-free process to fabricate bimodal mesoporous TiO2/I-2 composite nanocrystallites was developed by using tetrabutylorthotitanate [TiO(C4H9)(4), TBOT] and iodine hydrosol as precursor by hydrolysis precipitation method. The samples were characterized by XRD, TEM, BET, UV-Vis-DRS and FT-IR, respectively. The relation of the heat treatment temperatures and the photocatalysis activity of M-I-2-TiO2 were also studied. The photocatalytic activity of samples was evaluated by degradation of methylene blue (MB) as target pollutant. The results show that the bimodal mesoporous structured M-I-2-TiO2 exhibited stronger absorption in visible light region. The specific surface area of the bimodal mesoporous I-2-doped TiO2 thermal treatment in air at 300 degrees C exceeded 227.6 m(2)/g, and that of the samples thermal treatment in air at 600 degrees C still have 111.8 m(2)/g, which indicated the samples have relative high thermal stability. The TiO2/I-2 composite sample thermal treatment at 400 degrees C manifested the highest photocatalytic activity for photodecomposition of MB solution compared with thermal treatment at other temperatures, the uncomposite TiO2 and Degussa P-25 under the irradiation of visible-light. Little difference of the activity was observed between the samples used for 6 times.