TiO_2中孔分子筛的合成与X射线衍射分析

Synthesis of Mesoporous Titanium Dioxide and Its XRPD Analysis

利用X射线粉末衍射 (XRPD)对以十六烷基三甲基溴化铵 (CTAB)为阳离子模板剂合成的中孔TiO2 分子筛进行表征 ;XRPD研究表明分子筛的结构受到Ti与CTAB的物质的量之比和陈化时间的影响 ;当Ti与CTAB的物质的量之比为3 ,陈化时间为12h,可以形成孔径为4.5nm的六角相中孔结构 ;有机 -无机片段自组装过程显示TiO2 中孔分子筛的合成按照协同作用机理 (CFM)进行 ;后处理研究表明300℃烧结导致分子筛孔径分布变宽 ,孔径变大 ,进一步提高烧结温度将完全破坏中孔结构 ;

X - ray powder diffraction(XRPD) was used to characterized TiO2 mesoporous molecular sieves synthesized with cetyl trimethylammonium bromide(CTAB) as a cationic template. XRPD analyzed results demonstrated that the mole ratio of Ti to CTAB and ageing time had great effect on the structure. The hexagonal mesoporous structure was synthesized with pore size about 4.5 nm when the mole ratio of Ti to CTAB was about 3 and ageing time was 12 h. Inorganic-organic self - assembling process revealed that TiO2 mesoporous molecular sieves was synthesized according to cooperative formation mechanism(CFM). When the sample was calcined at 300 ℃, pore size distribution became wider and the pore size increased, furthermore, the mesoporous structure was destroyed when calcined at 350 ℃. The mesoporous structure could not be retained when the sample was treated by solution extraction method.