Synthesis and morphology control of AM-6 nanofibers with tailored -V-O-V- intermediates.
Synthesis and morphology control of AM-6 nanofibers with tailored -V-O-V- intermediates.
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DOI：
10.1002/chem.201301812
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发表时间：
2013-10
期刊：
影响因子：
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通讯作者：
M. Guo;Zhaochi Feng;J. Hofmann;B. Weckhuysen;Fengtao Fan;Can Li
中科院分区：
文献类型：
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作者：
M. Guo;Zhaochi Feng;J. Hofmann;B. Weckhuysen;Fengtao Fan;Can Li
通过控制初始凝胶混合物的Na/K摩尔比，水热合成了具有八面体VO 6和四面体SiO 4单元的微孔钒硅酸盐，更好地称为AM-6。当Na/K摩尔比从1.9降低到0.2时，AM-6材料的形态从大体积立方体变为小体积聚集体。拉曼光谱分析表明，VO 3（-）中间物种在纳米晶形貌的形成中起着重要作用。用共焦偏振显微拉曼光谱研究了-V-O-V-链在聚苯乙烯聚集体中的取向。研究发现，这些聚集体是垂直于纳米纤维轴向的短-V-O-V-链的组装体。所制备的AM-6纳米纤维大大增加了V_2 O末端的暴露比例，从而提高了催化性能。
Microporous vanadosilicates with octahedral VO6 and tetrahedral SiO4 units, better known as AM-6, have been hydrothermally synthesized with different morphologies by controlling the Na/K molar ratio of the initial gel mixtures. The morphology of the AM-6 materials changed from bulky cube to nanofiber aggregates as the Na/K molar ratio decreased from 1.9 to 0.2. Raman spectroscopy revealed that the VO3 (-) intermediate species plays an important role in the formation of the nanofiber morphology. The orientation of -V-O-V- chains in nanofiber aggregates was examined by confocal polarized micro-Raman spectroscopy. It was found that these aggregates are assemblies of short -V-O-V- chains perpendicular to the axis of nanofibers. The obtained AM-6 nanofibers greatly increase the exposed proportion of VO terminals, and thus improve the catalytic performance.