Si掺杂TiO2纤维的溶胶-凝胶法制备及其光催化活性

采用溶胶-凝胶法并结合水蒸气活化制备了Si掺杂TiO₂纤维, 通过TG-DSC, XRD, FT-IR, UV-Vis-DRS, N₂吸附-脱附, SEM等手段对纤维样品的结构参数及其表面形貌进行了表征, 并以活性艳红X-3B模拟废水体系评价了其光催化活性．结果表明, 与纯TiO₂产物相比, 适量Si掺杂制得的产物是具有丰富介孔结构的TiO₂长纤维, 不仅热稳定性和晶型稳定性俱佳, 而且光催化活性得以显著提高, 经900 ℃热处理后仍能保持结晶完好的锐钛矿相; 在Si/Ti摩尔比为0.15时, 其比表面积和孔容最大, 光催化活性最佳, 该纤维作为光催化剂反应75 min, 水中X-3B的降解率可达99.6%.

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, N₂ 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 ℃. 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.