铟是一种至关重要的材料，广泛应用于高科技产业，电沉积是回收稀有金属资源的有效方法。在这项工作中，通过使用不同的电化学方法在含有硫酸钠和硫酸铟的电解质中研究了In 3+的电化学行为。采用循环伏安法 (CV)、计时电流法 (CA) 和交流阻抗 (EIS) 技术研究了 In 3+的还原反应和铟在硫酸铟体系中的电结晶机理。循环伏安法结果表明电沉积过程是不可逆的。平均电荷转移系数一个根据阴极峰电位与半峰电位的关系，计算出In 3+为0.116，H +放电发生在In 3+负电位较高时。采用计时电流法分析了铟电沉积的成核机理。铟在-0.3 到-0.6 V 的电位步长处的机制接近于扩散控制的瞬时成核，扩散系数为7.31 × 10 -9 cm 2 s -1。EIS结果表明，In 3+的还原过程当 pH = 2.5 且外加电位为 -0.5 V 时，受扩散控制步骤的影响。 SEM 和 XRD 技术表明，沉积在钛电极上的阴极产物具有优异的清洁度和纯度。
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Electrochemical Mechanism of the Preparation of High-Purity Indium by Electrodeposition
Indium is a crucial material and is widely used in high-tech industries, and electrodeposition is an efficient method to recover rare metal resources. In this work, the electrochemical behavior of In3+ was investigated by using different electrochemical methods in electrolytes containing sodium and indium sulfate. Cyclic voltammetry (CV), chronoamperometry (CA), and alternating current impedance (EIS) techniques were used to investigate the reduction reaction of In3+ and the electrocrystallization mechanism of indium in the indium sulfate system. The cyclic voltammetry results showed that the electrodeposition process is irreversible. The average charge transfer coefficient a of In3+ was calculated to be 0.116 from the relationship between the cathodic peak potential and the half-peak potential, and the H+ discharge occurred at a higher negative potential of In3+. The nucleation mechanism of indium electrodeposition was analyzed by chronoamperometry. The mechanism of indium at potential steps of −0.3 to −0.6 V was close to diffusion-controlled instantaneous nucleation with a diffusion coefficient of 7.31 × 10−9 cm2 s−1. The EIS results demonstrated that the reduction process of In3+ is subject to a diffusion-controlled step when pH = 2.5 and the applied potential was −0.5 V. SEM and XRD techniques indicated that the cathodic products deposited on the titanium electrode have excellent cleanliness and purity.