TiO_2-SiO_2复合气凝胶的制备及其分解甲基橙的研究

Research on Preparation of TiO_2-SiO_2 Composite Aerogel and Degradation of Methyl Orange

采用溶胶-凝胶工艺,经超临界干燥,600℃、2h煅烧制得TiO2-SiO2复合气凝胶,其中TiO2为锐钛矿型,SiO2为无定形;以甲基橙为模拟废水,TiO2-SiO2气凝胶分解甲基橙的浓度范围为≤100mg/L,分解速率随着时间的变化而变化,前期呈线性关系,后期呈曲线关系;最大分解甲基橙的量约为30mg甲基橙/g气凝胶,采用400℃煅烧1h的活化方式可使气凝胶的重复使用寿命大于3次。

TiO2 - SiO2 composite aerogel is prepared in two hours under 600℃ by the sol - gel method and supercritical drying technique, among which TiO2 is anatase and SiO2 is amorphous. By using methyl orange as simulated wastewater, the density of degradation of methyl orange by TiO2 - SiO2 composite aerogel is less than 100mg/L and degradation rate changes with time, showing liner relationship in the first phase and curve relationship in the latter phase. The maximum dose of degrading methyl orange is about 30mg/g （ methyl orange/aerogel）. The TiO2 -SiO2 composite aerogel can be reused more than three times by adopting calcination method of one hour under 400℃.