Electrodeposition of Zinc from the Lewis Acidic Aluminum Chloride‐1‐Methyl‐3‐ethylimidazolium Chloride Room Temperature Molten Salt
Electrodeposition of Zinc from the Lewis Acidic Aluminum Chloride‐1‐Methyl‐3‐ethylimidazolium Chloride Room Temperature Molten Salt
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DOI：
10.1149/1.1837965
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发表时间：
1997-09
影响因子：
3.9
通讯作者：
W. Pitner;C. Hussey
中科院分区：
文献类型：
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作者：
W. Pitner;C. Hussey
在含电生锌（II）的60.0 ~ 40.0摩尔的氯化铝-1-甲基-3-乙基咪唑氯化铝熔盐中，研究了锌在多晶金、铂、钨和玻碳上的电沉积。锌在所有多晶金属电极上的电沉积之前，都有类似于之前在水溶液中进行的研究中报道的欠电位沉积过程。发现欠电位位移随锌和金属衬底的功函数的差异呈线性变化。相比之下，锌在玻璃碳上的电沉积需要大量的成核过电位。在这种衬底上电沉积锌的无因次时电流-时间瞬态与核的半球形扩散控制生长的渐进三维成核极限情况下的理论瞬态很好地吻合。用原子成核理论分析了玻璃碳的成核动力学，表明在沉积过程的初始阶段，玻璃碳表面的活性位点起着临界核的作用。在40℃时，Zn (II)/Zn对的形式电位比纯熔体Al (III)/Al对的形式电位大0.322±0.001 V，锌（II）的扩散系数为（6.7±0.4）× 10-7 cm 2 s-'。
The electrodeposition of zinc on polycrystalline gold, platinum, and tungsten and on glassy carbon was investigated in the 60.0-40.0 mole percent aluminum chloride-1-methyl-3-ethylimidazolium chloride molten salt containing electrogenerated zinc (II). The electrodeposition of zinc on all of the polycrystalline metal electrodes was preceded by underpotential deposition processes similar to those reported previously during studies carried out in aqueous solutions. The underpotential shift was found to vary linearly with the difference in the work functions of zinc and the metallic substrate. In contrast, the electrodeposition of zinc on glassy carbon required a substantial nucleation overpotential. Dimensionless chronoamperometric current-time transients for the electrodeposition of zinc on this substrate were in good accord with the theoretical transients for the limiting case of progressive three-dimensional nucleation with hemispherical diffusioncontrolled growth of the nuclei. Analysis of the nucleation kinetics by using the atomistic theory of nucleation suggested that active sites on the glassy carbon surface played the role of critical nuclei during the initial stages of the deposition process. The formal potential of the Zn (II)/Zn couple at 40 C was found to be 0.322±0.001 V vs. the Al (III)/Al couple in pure melt, and the diffusion coefficient of zinc (II) was determined to be (6.7±0.4) x 10-7 cm 2 s-'.