Conversion of ZnO Nanowires into Nanotubes with Tailored Dimensions
Conversion of ZnO Nanowires into Nanotubes with Tailored Dimensions
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DOI：
10.1021/cm801131t
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发表时间：
2008-11-11
影响因子：
8.6
通讯作者：
Levy-Clement, Claude
中科院分区：
文献类型：
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作者：
Elias, Jamil;Tena-Zaera, Ramon;Levy-Clement, Claude
提出了一种新颖的方法来获得尺寸定制的单晶ZnO纳米管阵列。该三步法结合了电化学和化学方法。第一步是在电沉积ZnO纳米线阵列从O-2还原在氯化锌（ZnCl 2）和氯化钾（KCl）的水溶液中。在第二步中，在KCl溶液中选择性地蚀刻ZnO纳米线的核心，从而形成管状结构。研究了KCl浓度、温度和浸泡时间对ZnO纳米管形成过程的影响，发现当[KCl] >= 1 M时，纳米线芯发生溶解，并且随着温度的升高，纳米线芯的刻蚀速率加快。通过改变纳米线阵列沉积的条件并考虑纳米线的尺寸来调节溶解时间，获得具有定制尺寸（200-500 nm外径和1-5 μ m长度）的ZnO纳米管阵列。通过进行进一步的电沉积步骤来实现纳米管壁厚度的精确控制。整个过程发生在低温（80摄氏度）在氯化物水溶液在中性pH值，在几个小时。通过透射电子显微镜分析了所得ZnO纳米管的结构性质，表明其具有单晶特征。
An innovative route is presented to obtain arrays of single-crystal ZnO nanotubes with tailored dimensions. The three-step process combines electrochemical and chemical approaches. The first step consists in the electrodeposition of ZnO nanowire arrays from the O-2 reduction in an aqueous solution of zinc chloride (ZnCl2) and potassium chloride (KCl). In the second step the core of ZnO nanowires is selectively etched in a KCl solution, resulting in the formation Of tubular structures. The influence of KCl concentration, temperature, and immersion time in the ZnO nanotube formation process is investigated, with the finding that the dissolution of the nanowire core occurs for [KCl] >= 1 M and the etching rate is enhanced with the temperature. Arrays of ZnO nanotubes with tailored dimensions (200-500 nm external diameter and 1-5 mu m length) are obtained by varying the conditions of nanowire array deposition and taking into account the dimensions of the nanowires to adjust the dissolution time. A precise control of the nanotube wall thickness is achieved by performing a further electrodeposition step. The whole process occurs at low temperature (80 degrees C) in aqueous chloride Solution at neutral pH, in a couple of hours. The structural properties of obtained ZnO nanotubes are analyzed by transmission electron microscopy, showing their single-crystal character.