【摘要】 采用溶胶-凝胶过程和非超临界干燥法制备了TiO2/SiO2气凝胶,并对所得样品的结构进行了表征,研究了TiO2/SiO2气凝胶对亚甲基蓝(MB)降解的光催化活性.结果表明TiO2/SiO2气凝胶是一种轻质的连续多孔性块状材料,具有较高的机械强度;依据制备条件的不同,TiO2/SiO2气凝胶的比表面积在300～400m2·g-1范围内,平均孔径为20～40nm,孔体积在1～2cm3·g-1之间;TiO2/SiO2气凝胶对亚甲基蓝降解的光催化活性远高于粉末状的TiO2;钛硅的摩尔比n(TiO2)∶n(SiO2)=1∶6时制得的TiO2/SiO2气凝胶,经600℃焙烧热处理,在弱碱性条件下对亚甲基蓝降解的光催化活性较高;TiO2/SiO2气凝胶对亚甲基蓝降解反应的活化能为8.706kJ·mol-1.更多还原

【Abstract】 TiO₂/SiO₂ aerogels are produced through sol-gel process followed by non-supercritical drying with the structure of their samples characterized,and photocatalytic activity of the resultant aerogels for degradation of methylene blue （MB） is also studied.It is demonstrated that the TiO₂/SiO₂ aerogels are coherent porous monolithic materials with low density and high mechanical intensity.Due to the variations of preparation conditions,the specific surface areas of aerogels are in the range of 300～400 m2·g -1 , their average pore sizes vary from 20 nm to 40 nm, and their pore volumes are 1～2 cm3·g -1 .Photocatalytic activity of TiO₂/SiO₂ aerogels for MB’s degradation is much higher than that of TiO₂ powders.TiO₂/SiO₂ aerogels produced on the basis of a titanium/silicon molar ratio of 1∶6 and heat treatment at 600 ℃ have optimum photocatalytic activity for MB’s degradation under alkalescent condition.The activation energy of MB’s degradation reaction for TiO₂/SiO₂ aerogels is 8.706 kJ·mol -1 .更多还原