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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1.78h-1。
Firstly, a large-size and large-pore SiO2 carrier was prepared by the sol-gel process of silicate in situ and sintering at high temperature by using the three-dimensional framework polymer as a monolithic template and then impregnated with butyl titanate solution to hydrolyze in situ , Calcined to prepare a large size TiO2 / SiO2 macroporous material and characterized by SEM, TEM, FTIR, XRD and XPS. The results show that the SiO2 support has a three-dimensional continuous ultrathin layer, and TiO2 is uniformly deposited on the surface of the SiO2 Ti / SiO2 / TiO2 three-layer sandwich structure is formed on the three-dimensional ultrathin layer. The Si-O-Ti bond exists at the interface of layer and layer, and the composite structure increases the transition temperature of TiO2 from anatase phase to rutile phase. The photocatalytic activity of the composites prepared under different conditions was investigated using methyl orange as degradation product. The photodegradation kinetics of the composites was studied by means of methanol-in-solution. The results show that the composite has good photodegradation activity. When the calcination temperature is 600 ℃ and the loading of TiO2 is 54.5wt%, its activity is the highest and its degradation rate constant is 1.78h-1.