We report on the effect of the substrate on electrochemical deposition of Cu from deep eutectic solvent ethaline. We investigated the polarization behavior during electrodeposition of Cu on Pt and glassy carbon (GC) from both Cu²⁺ and Cu⁺ containing ethaline using cyclic voltammetry (CV). Formation of bulk Cu deposits on both substrates underwent nucleation and growth processes; however, the nucleation was considerably sluggish on GC compared to Pt. While experiments in Cu⁺ solutions indicated that coalescence of Cu islands on Pt is a slow process and that its surface may not be fully covered by Cu, such determination of Cu coverage could not be made on GC. Cu dissolution is also slower from GC than from Pt. It was observed that CV of Cu deposition on GC is influenced by the surface preparation method. Since ethaline has high chloride concentration, a parallel study in aqueous 3 M NaCl solution was conducted in order to examine the influence of the chloride medium on the electrodeposition process. This revealed that electrodeposition in both media occurred in the same manner but with different charge and mass transfer rates caused by the differences in viscosity and chloride concentrations of the two solutions.

中文翻译：

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深共晶溶剂中的铜电沉积-伏安法研究，可洞悉基质的作用：铂与玻璃碳。

我们报告了从深共熔溶剂乙醇中铜对电化学沉积基底的影响。我们使用循环伏安法（CV）研究了Cu在Pt和玻璃碳（GC）上的电沉积过程中的极化行为，其中Cu ²⁺和Cu ^+都含有乙胺。在两个衬底上形成大量的铜沉积物都经历了成核和生长过程；但是，与Pt相比，GC的成核作用很慢。在Cu ^+中进行实验解决方案表明，Pt上的铜岛的聚结是一个缓慢的过程，其表面可能没有被Cu完全覆盖，因此无法在GC上确定Cu的覆盖率。GC中的铜溶解也比Pt中的铜溶解慢。观察到表面沉积方法会影响Cu在GC上沉积的CV。由于乙胺胆碱具有较高的氯化物浓度，因此在3 M NaCl水溶液中进行了平行研究，以检查氯化物介质对电沉积过程的影响。这表明两种介质中的电沉积以相同的方式发生，但由于两种溶液的粘度和氯化物浓度不同而导致电荷和传质速率不同。