宏观尺寸大孔-介孔TiO2-SiO2光催化剂的制备及其在染料降解中的应用宏观尺寸大孔-介孔TiO2-SiO2光催化剂的制备及其在染料降解中的应用

Preparation of macro-sized macro-mesoporous TiO2-SiO2 photocatalyst and its application in dye degradation

  • 摘要: 以柱撑式环氧树脂大孔聚合物为模板,制备宏观尺寸的大孔-介孔SiO2;以其为载体,通过钛酸四丁酯原位水解和高温焙烧制得大孔-介孔TiO2纳米晶-SiO2复合材料。应用SEM、TEM、XRD、FTIR和N2吸附-脱附法对材料进行表征。以偶氮荧光桃红为模拟污染物,用氙灯模拟日光光源,考察了不同条件下大孔-介孔TiO2-SiO2的光催化性能。结果表明,大孔-介孔SiO2具有三维连续贯通的大孔孔道,孔壁为连续的纳米SiO2薄膜;TiO2纳米晶以纳米薄膜的形式均匀地原位生长在SiO2纳米薄膜的两侧,得到的复合材料孔壁上存在丰富的介孔。当焙烧温度为600℃、TiO2的负载量为15.7wt%、染料溶液浓度为10 mgL-1且pH为3时,大孔-介孔TiO2-SiO2光催化剂对污染物的光催化降解效率最高,而且具有良好的重复使用性。

     

    Abstract: The macro-sized macro-mesoporous SiO2 was prepared by using a pillared epoxy resin macroporous polymer as the template and it was used as support to prepare macro-mesoporous TiO2 nanocrystalline-SiO2 composite through an in situ hydrolysis of tetrabutyl titanate and a subsequent calcination at high temperature. The macro-mesoporous TiO2-SiO2 samples were characterized by SEM, TEM, XRD, FTIR and N2 adsorption-desorption. Using azophloxine as a simulated pollutant, the photocatalytic activity of the macro-mesoporous TiO2-SiO2 was studied under the sunlight irradiation simulated by Xenon lamp under different conditions. The results show that the macro-mesoporous SiO2 has 3D continuous pass-through macropore structure and its pore wall is continuous SiO2 nano-film. TiO2 nanocrystallines, in the form of nano-film, in situ grow uniformly on both sides of the nano SiO2 film, and abundant mesopores were observed on the pore wall of the obtained macro-mesoporous TiO2-SiO2 composite. The macro-mesoporous TiO2-SiO2 photocatalyst exhibits the best activity for photocatalytic degradation of pollutant from the macro-mesoporous TiO2-SiO2 composite containing 15.7wt% of TiO2 calcined at 600℃, under the conditions of azophloxine concentration 10 mgL-1 and pH of 3. The macro-mesoporous TiO2-SiO2 photocatalyst also has good reusability.

     

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