Hou Zhongmin, Wang Xiaomin, Li Jidong, Li Zhen, Wang Yiyong, Xing Hongxuan
Liaoning Key Laboratory of Chemical Additive Synthesis and Separation, School of Materials Science and Engineering, Yingkou Institute of Technology, Liaoning Yingkou, China.
School of Materials and Metallurgy, University of Science and Technology Liaoning, Liaoning Anshan, China.
Front Chem. 2022 May 24;10:871420. doi: 10.3389/fchem.2022.871420. eCollection 2022.
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 In 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 In 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 of In 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 In. 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 cm s. The EIS results demonstrated that the reduction process of In 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.
铟是一种关键材料，广泛应用于高科技产业，而电沉积是回收稀有金属资源的一种有效方法。在本工作中，采用不同的电化学方法在含钠和硫酸铟的电解质中研究了铟的电化学行为。运用循环伏安法（CV）、计时电流法（CA）和交流阻抗（EIS）技术研究了硫酸铟体系中铟的还原反应及铟的电结晶机理。循环伏安法结果表明电沉积过程是不可逆的。根据阴极峰电位与半峰电位的关系计算出铟的平均电荷转移系数为0.116，且氢在比铟更正的负电位下放电。通过计时电流法分析了铟电沉积的成核机理。在-0.3至-0.6 V的电位阶跃下铟的机理接近扩散控制的瞬时成核，扩散系数为7.31×10 cm² s⁻¹。EIS结果表明，当pH = 2.5且施加电位为-0.5 V时，铟的还原过程受扩散控制步骤的影响。扫描电子显微镜（SEM）和X射线衍射（XRD）技术表明，沉积在钛电极上的阴极产物具有优异的洁净度和纯度。
