Chemical Vapor Deposition of Silica Micro- and Nanoribbons Using Step-Edge Localized Water
Chemical Vapor Deposition of Silica Micro- and Nanoribbons Using Step-Edge Localized Water
复制标题
使用阶梯边缘局部水化学气相沉积二氧化硅微带和纳米带
DOI：
10.1021/jp034452k
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Penner
中科院分区：
文献类型：
--
作者：
M. Zäch;J. Newberg;L. Sierra;J. Hemminger;R. Penner
通过水解高取向热解石墨（HOPG）表面的SiCl 4制备了无定形SiO2（SiO2）带。在室温下暴露于潮湿空气（>30%相对湿度（RH））导致水在原本疏水的石墨表面上的亲水台阶边缘处选择性地冷凝。当该表面暴露于SiCl 4蒸汽时，根据SiCl 4 + 2 H2O → SiO2 + 4 HCl的反应，与台阶边缘处的冷凝水反应，导致形成SiO2。SiO2纳米结构的形状和尺寸随相对湿度的变化而变化：在20% RH以下，观察到SiO2纳米颗粒在台阶边缘排列。在相对湿度为35- 50%的条件下，得到了连续的SiO2纳米带和微米带.对于较高的RH，微米级的二氧化硅颗粒和带状物都观察到。在相对湿度为35%的条件下，可以制备出宽80 nm，高20-40 nm，长500 μm的硅带。在潮湿的环境中与SiCl 4的HOPG表面的重复给药产生的纳米和microribbons的高度和宽度，增加的SiCl 4剂量的平方根成比例。
Amorphous silica (SiO 2 ) ribbons were prepared by hydrolyzing SiCl 4 at highly oriented pyrolytic graphite (HOPG) surfaces on which water had condensed. Exposure to humid air (>30% relative humidity (RH)) at room temperature caused water to condense selectively at hydrophilic step edges on an otherwise hydrophobic graphite surface. Upon exposure of this surface to SiCl 4 vapor, a reaction with condensed water at step edges caused the formation of SiO 2 according to the reaction SiCl 4 + 2H 2 O → SiO 2 + 4HCl. The shape and size of the SiO 2 nanostructures varied with the RH: Below 20% RH, nanoparticles of SiO 2 , aligned at step edges, were observed. For RH of 35-50%, continuous nano- and microribbons of SiO 2 were obtained. For higher RH, micron-scale silca particles and ribbons were both observed. At a RH of 35%, silica ribbons as small as 80 nm (width) x 20-40 nm (height) up to 500 μm in length could be prepared. Repetitive dosing of the HOPG surface in the humid environment with SiCl 4 produced nano- and microribbons with a height and width that increased in proportion to square root of the SiCl 4 dose.