Thermodynamic to Kinetic Transition in Epitaxial Electrodeposition
Thermodynamic to Kinetic Transition in Epitaxial Electrodeposition
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DOI：
10.1021/jp014638o
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发表时间：
2002-03
影响因子：
3.3
通讯作者：
J. Switzer;H. Kothari;E. Bohannan
中科院分区：
文献类型：
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作者：
J. Switzer;H. Kothari;E. Bohannan
氧化亚铜的有序纳米结构在从热力学控制的取向转变为动力学择优取向后沉积在单晶金上。在pH为12时，氧化亚铜在Au(100)表面上形成了具有20×100 nm正交纳米线形态的交叉阴影图案。开发了一种独特的电沉积资产来沉积这些纳米结构：通过简单地选择施加的电极过电位，以毫伏的精度控制偏离平衡的状态。过电位的微小变化会使薄膜的形态发生显著变化。在低过电势(即接近平衡)时，电沉积薄膜沿单晶衬底的[100]取向生长，而在阈值过电势为−118mV时，电沉积薄膜转变为动力学择优的[110]取向。取向的突变是由Au(100)表面上形成的三维岛屿的融合所触发的。
Ordered nanostructures of cuprous oxide are deposited onto single-crystal gold after a transition from a thermodynamically controlled orientation to a kinetically preferred orientation. Crosshatch patterns of cuprous oxide with a 20 by 100 nm orthogonal nanowire morphology are formed at pH 12 on Au(100). A unique asset of electrodeposition is exploited to deposit these nanostructures: the departure from equilibrium is controlled with millivolt precision by simply selecting an applied electrode overpotential. Small changes in overpotential produce dramatic changes in the morphology of the films. The electrodeposited films follow the [100] orientation of the single-crystal substrate at low overpotential (that is, close to equilibrium) but change to a kinetically preferred [110] orientation at a threshold overpotential of −118 mV. The abrupt change of orientation is triggered by the coalescence of three-dimensional islands that form on the Au(100) surface.