Photodecomposition of Methylene Blue by the S, Al Doped TiO_2 Mesoporous Materials

摘要

Mesoporous sulfur, aluminium doped TiO_2 materials (S-Al-TiO_2, S-TiO_2, Al-TiO_2) have been synthesized by solid-state reaction route. The textural properties of the samples are monitored by the X-ray diffraction (XRD), Scanning electron micrography (SEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet visible light spectroscopy (UV-Vis) and N_2-physisorption. Moreover, compared with the pure TiO_2, the photodecomposition properties of methylene blue (MB) irradiated with ultraviolet and visible light are presented on the doped TiO_2 materials. It is shown that TiO_2 doped by sulfur and /or aluminium are mesoporous materials, and the S and Al enter into the crystal lattice of TiO_2. At 298K, the rule of pseudo-first-order reaction and excellent visible light catalytic activity are obtained in the photodecomposition of MB on the S-Al-TiO_2, S-TiO_2, Al-TiO_2 and pure TiO_2 materials. Interestingly, the reaction rate constant of MB on the S-Al-TiO_2 meso- porous nanomaterial is 11.40 times irradiated with the ultraviolet than that with visible light irradiation. But there is 1.42 times corresponding to the pure TiO_2. Within 50 min, ultraviolet degradation rate of MB over the S-Al-TiO_2 is 98.5%.