From copper nanocrystalline to CuO nanoneedle array: Synthesis, growth mechanism, and properties
From copper nanocrystalline to CuO nanoneedle array: Synthesis, growth mechanism, and properties
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DOI：
10.1021/jp069043d
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发表时间：
2007-04-05
影响因子：
3.7
通讯作者：
Pan, Chunxu
中科院分区：
文献类型：
--
作者：
Liu, Yueli;Liao, Lei;Pan, Chunxu
本文介绍了一种合成一维CuO纳米针阵列的新方法；即首先采用周期性反脉冲镀工艺镀上纯铜纳米晶层，然后在空气中热氧化生长出CuO纳米针阵列。采用扫描电子显微镜、常规和高分辨率透射电子显微镜、x射线衍射、x射线光电子能谱和热分析系统（热重法和差示扫描量热法）对纳米晶层和纳米针进行了表征。结果表明，氧化温度和Cu2O中间相对CuO纳米针的生长起关键作用。提出了一种基于自催化的扩散模型来解释纳米针的生长机理。纳米针的场发射特性表明，在电流密度为10 μ A cm（-2）时，电子发射导通场约为0.5 V μ m(-1)，最大电流密度为2.5 mA cm(-2)，并呈线性F-N关系。在染料敏化太阳能电池中用作阴极的CuO纳米针的全太阳效率（eta）为1.12%，表明它是一种潜在的太阳能电池材料。
In the present work, a novel method for synthesizing a one-dimensional CuO nanoneedle array was introduced; that is, first, a pure copper nanocrystalline layer was plated by using a periodic reverse pulse plating process, and then the CuO nanoneedle array grew upon the layer through thermal oxidation in the air. The nanocrystalline layer and nanoneedles were characterized by using scanning electron microscopy, regular and high-resolution transmission electron microscopies, X-ray diffraction, X-ray photoelectron spectroscopy, and a thermal analysis system (thermogravimetry and differential scanning calorimetry). The results showed that the oxidation temperature and the Cu2O intermediate phase played key roles for growing CuO nanoneedles. A self-catalyzed based-up diffusion model was proposed for interpreting the nanoneedles' growth mechanism. The field emission property of the nanoneedles showed that the electron emission turn-on field is about 0.5 V mu m(-1) at current density 10 mu A cm(-2), and the maximum current density is 2.5 mA cm(-2) with a linear F-N relationship. The full Sun efficiency (eta) of the CuO nanoneedle used as a cathode in dye-sensitized solar cells is 1.12%, which shows it to be a potential material in solar cells.