Silica-based nanospheres, nanowires, nanosubstrates, nanotubes, and nanofiber arrays
Silica-based nanospheres, nanowires, nanosubstrates, nanotubes, and nanofiber arrays
复制标题
二氧化硅基纳米球、纳米线、纳米基底、纳米管和纳米纤维阵列
DOI：
10.1007/s00396-002-0819-4
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发表时间：
2003
影响因子：
2.4
通讯作者：
M. White
中科院分区：
文献类型：
--
作者：
J. Gole;Zhong Lin Wang;Z. Dai;J. D. Stout;M. White
基于二氧化硅的纳米球，纳米球线状团聚体，纳米管，和纳米管阵列，双和同轴SiC/SiO2纳米线，和二氧化硅纳米衬底已产生和它们的结构，机械和催化性能的检查。以克为单位合成了直径≤30 nm的几乎单分散的SiO2纳米球，并将其用于螯合活性铜位点，以使乙醇选择性催化转化为乙醛，其效率至少是使用四氯化硅火焰水解产生的气相二氧化硅的三倍。一个镍（III）的解决方案已减少在无电过程中的纳米球的表面上，产生可变厚度的铁磁结晶镍涂层。部分团聚的SiO2纳米球的直径为45 nm已被用作纳米衬底的SnOx微晶的直径为3-6 nm。更小的纳米球（d≤10 nm）聚集成线状结构，这表明了生长二氧化硅纳米管和产生独特的二氧化硅纳米管阵列的方法。生成的二氧化硅纳米管可以满足高分子量烃（MW> 1000）的催化转化的现有需求。同轴和并排双轴结构的碳化硅-二氧化硅纳米线现在也产生了C/Si/SiO2混合物。这些纳米线的结构，它们的横截面形状，和它们的双轴和同轴配置之间的结构转换进行了研究。双轴结构的纳米线的杨氏模量已被测量为50-100 GPa，这取决于纳米线的尺寸。
Silica-based nanospheres, nanosphere wire-like agglomerates, nanotubes, and nanofiber arrays, bi- and coaxial SiC/SiO2nanowires, and silica nanosubstrates have been generated and their structural, mechanical, and catalytic properties examined. Nearly monodisperse SiO2nanospheres of diameter ≤30 nm have been synthesized in gram quantities and used to sequester active copper sites for the selective catalytic conversion of ethanol to acetaldehyde in a process that is at least three times more efficient than that which uses fumed silica produced from the flame hydrolysis of silicon tetrachloride. A Ni(III) solution has been reduced in an electroless process on the surface of the nanospheres, producing a ferromagnetic crystalline nickel coating of variable thickness. Partially agglomerated SiO2nanospheres of diameter ∼45 nm have been used as nanosubstrates for SnOxcrystallites of diameter 3–6 nm. The agglomeration of smaller nanospheres (d≤10 nm) to wire-like configurations has suggested the means to grow silica nanotubes and to produce unique silica nanofiber arrays. Generated silica nanotubes may fill an existing need for the catalytic conversion of high molecular weight hydrocarbons (MW∼1000). Both coaxial and side-by-side biaxially structured silicon carbide-silica nanowires have now also been generated from C/Si/SiO2mixtures. The structure of these nanowires, their cross-sectional shape, and their structural transformation between a biaxial and coaxial configuration have been studied. The Young's modulus of the biaxially structured nanowires has been measured to be 50–100 GPa, depending on the size of the nanowires.