Preparation of Si-doped TiO2 fibers by sol-gel method and its photocatalytic activity

Pure TiO2 and Si-doped TiO2 fibers were prepared by a sol-gel method combined with vapor activation. The structural parameters and surface morphology were characterized by the techniques such as TG-DSC, XRD, FT-IR, UV-Vis-DRS, N-2 absorption-desorption and SEM. The photocatalytic degradation of X-3B in aqueous solution was used as a probe reaction to evaluate their photocatalytic activities. The results indicate that compared with pure TiO2, the sample prepared with a proper dopant of Si is a TiO2 long fiber with an abundant mesoporous structure, which not only possesses excellent thermal stability and crystal stability, but also has much higher photocatalytic activities. The results also indicate that the anatase phase can be maintained even after calcination at 900 degrees C. The sample has the largest specific surface area, pore volume and the best photocatalytic activity when the molar ratio of Si/Ti is 0.15. Under optimum condition, 99.6% of X-3B was degraded after irradiation within 75 min under UV-light.