Using cetyltrimethyl ammonium bromide as template and tetraethyl orthosilicate( TEOS) as silicon source,ordered mesoporous TiO2 -SiO2 composites(TiO2NPs/MCM-41 or TiO2NPs/SBA-3) were synthesized in dopamine - modified water - based TiO2 nanoparticles ( TiO2 NPs ) suspension by basic hydrothermal synthesis procedure or acidic sol-gel method. The mesoporous TiO2 -SiO2 composites were characterized by small- and wide-angle XRD,TEM,ICP and nitrogen adsorption-desorption experiments. The results showed that the synthetic samples still maintained highly ordered mesoporous silica structure even with high TiO2 loading mass fraction of 23. 98% and 17. 27% for TiO2 NPs/MCM-41 and TiO2 NPs/SBA-3,respectively. TiO2 NPs were randomly embedded in framework of the mesoporous silica channels. In the photocatalytic degradation of methyl orange under visible light irradiation for reaction time 120 min,the relative concentration value(C/C0) of methyl orange was reduced to 57%,33% and 5. 7%over P25,TiO2 NPs/MCM-41 and TiO2 NPs/SBA-3,respectively.%在多巴胺修饰的水基TiO2纳米微粒(TiO2NPs)悬浮液中,以正硅酸乙酯为硅源,十六烷基三甲基溴化铵为模板剂,分别采用碱性水热方法或酸性溶胶-凝胶方法,制备了有序介孔TiO2-SiO2(TiO2NPs/MCM-41或TiO2NPs/SBA-3).采用XRD、TEM、ICP和N2吸附-脱附实验对样品进行表征.结果表明,制备的介孔TiO2-SiO2在TiO2高负载质量分数(23.98%TiO2NPs/MCM-41、17.27%TiO2NPs/SBA-3)时,仍能保持长程有序的介孔氧化硅结构.TiO2NPs随机地嵌入在有序介孔氧化硅孔道所组成的网络结构中.在可见光下催化甲基橙降解反应中,反应时间120 min时,在P25上甲基橙相对浓度降为57%,在TiO2NPs/MCM-41上降为33%,而在TiO2NPs/SBA-3上降为5.7%.
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