| 大尺寸TiO2/SiO2大孔材料的制备及光降解性能 |
| Preparation and Photo-degradation of Large-sized TiO2/SiO2 Macroporous Materials |
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| 摘要: 先以三维骨架聚合物为整体型模板，利用硅酸酯原位溶胶-凝胶过程并结合高温烧结的方法制备出大尺寸大孔径的SiO2载体，然后通过钛酸丁酯溶液浸渍、原位水解、煅烧制备出大尺寸的TiO2/SiO2大孔材料并用SEM、TEM、FTIR、XRD和XPS对其表征，结果表明SiO2载体具有三维连续的超薄层，TiO2以纳米薄层方式均匀地沉积在SiO2的三维超薄层上，形成TiO2/SiO2/TiO2三层夹心结构，层与层界面存在Si-O-Ti键，同时复合结构提高了TiO2由锐钛矿相向金红石相的转变温度。以甲基橙为目标降解物考察不同条件下制备的复合材料的光催化活性，采用复合材料吸入甲基橙溶液的方式，并借助甲醇萃取手段研究光降解动力学过程。结果表明，该复合材料具有较好的光降解催化活性，当焙烧温度为600 ℃和TiO2的负载量为54.5wt%时，其活性最大且降解速率常数达到1.78 h-1。 |
| 关键词: 二氧化硅载体 纳米二氧化钛 光催化降解 |
| 基金项目: |
| Abstract: A large sized macroporous SiO2 support was prepared by using a three-dimensional(3D) skeletal polymer as template through an in situ sol-gel process of ethyl silicate and a subsequent calcination at high temperature. By immersing the support in a solution of tetrabutyl titanate in cyclohexane followed by in situ hydrolysis in air and a final calcination, TiO2 was loaded on the surface of the support to provide TiO2/SiO2 complexes. The material was characterized by SEM,TEM, FTIR, XRD and XPS. The results show 3D ultrathin layer in the SiO2 support, Si-O-Ti bonds formation in the interface between thin layers of SiO2 and TiO2, and a higher temprature for transition of anatase to rutile. Methyl orange was used to investigate the photo-degradation activity of the catalysts obtained under different conditions. The kinetic process was studied by infiltrating aqueous solution of methyl orange over the large sized catalyst. The TiO2/SiO2 catalyst exhibites a better activity for photo-degradation of methyl orange and the highst rate constant of 1.78 h-1 was obtained from the catalyst containing 54.5wt% of TiO2 calcined at 600 ℃. |
| Keywords: SiO2 support nano-TiO2 photocatalytic degradation |
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| 龙能兵,张瑞丰.大尺寸TiO2/SiO2大孔材料的制备及光降解性能[J].无机化学学报,2009,25(7):1153-1158. |
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