Abstract:

Active brilliant red X- 3B is used as a model compound to evaluate the photocatalytic activity of the silica -doped TiO₂ fiber. The factors affecting photocatalytic activity are studied by means of TG - DSC, N₂ absorption-desorption, XRD, SEM and so on. Those factors include the calefactive mode, the activation temperature and the content of doped silica during the preparation process. The results are as follows : ( 1) 15 SiO₂/TiO₂ ( 15 denotes the mol percentage of Si) shows the best photoactivity, which is prepared by stagetemperature-programmed technics, and subsequently heated to 700 ℃ in vapor atmosphere, reaction time 2 h. The X- 3B photocatalytic degradation rate can reach as high as 99.3% after 75 min of the reaction time. X- 3B is photocatalytically degraded via decolorization and mineralization sequentially.( 2)Optimum amount of doped silica can effectively suppress the phase transformation of titania, prevent the growth of titania, and improve their thermal stabilities and surface structure characteristics.The silica-doped TiO₂ fiber is a kind of novel functional material in water treatment, which possesses high photocatalytic activity and is easy to be recycled.

Key words: silica-doped TiO₂ fiber, photocatalytic activity, active brilliant red X- 3B, activation technics

摘要：

以水中活性艳红X-3B为研究对象评价了自制掺硅TiO₂纤维的光催化活性,结合TG-DSC、N₂吸脱附、XRD及SEM等手段,探讨了制备过程中升温方式、活化温度及掺硅量等工艺条件对光催化活性的影响。结果表明:(1)采用分段程序升温工艺,前驱体经700℃水蒸气活化2 h,硅的摩尔分数为15%时制得的TiO₂纤维光催化活性最佳,反应75 min后X-3B的降解率达99.3%,其降解过程分为脱色和矿化两个阶段;(2)掺硅可有效抑制TiO₂的晶相转变及晶粒生长,提高热稳定性并改善表面织构。掺硅TiO₂纤维光催化活性高又易于分离回收,是一类新型的水处理光催化功能材料。

关键词: 掺硅TiO₂纤维, 光催化活性, 活性艳红X-3B, 活化工艺

CLC Number: 

• X703.1