Effect of Tin Ion on Electrodeposition Behavior of Indium

Abstract

Electrorefining is an effective method for preparing high-purity indium. To realize the control of impurity Sn in crude indium electrolytic refining, electrochemical test methods, such as cyclic voltammetry (CV), and chronoamperometry (CA) were mainly used to study the electrochemical behavior of indium. The results show that when a few of SnSO 4 was added to the electrolyte containing indium sulfate, in the meantime, the Sn 2+ concentration reached 5000 ppm, in the electrolysis process, the impurity Sn in the cathode was appeared to precipitate before the indium precipitated. The electrodeposition of indium was irreversible, controlled by diffusion steps, and In 3+ reduction was carried out by fractional steps, transferring one electron at a time. The diffusion coefficient of In 3+ calculated by cyclic voltammetry was 1.02 × 10 −7 cm 2 /s, and the average charge transfer coefficient was 0.081. The nucleation mechanism of indium conformed to three-dimensional instantaneous nucleation. The results provide theoretical guidance for electrolytic refining of crude indium and electrochemical regulation of impurities.

Preparation of Co–Ni–Ce/TiC alloy coatings by double-pulse under a sulfamic acid system and a process mechanism study

“…To further determine the steps controlling the redox reactions of Ce 3+ , the relationships between the peak currents I pc and v 1/2 were investigated. The cathodic peak potential E pc and half peak potential E pc/2 satisfied the following equation: 25 …”

Repair of soft magnetic properties of wasted silicon steel and Co7Fe3 alloy deposition mechanism

“…The nucleation mode of Co 2+ and Fe 2+ at the deposition potential can be obtained by selecting different points from the stages of chronoamperometric curves and fitting them according to eqn (4) and (6). 18…”

“…Combining the known data, including the working electrode surface area, S = 4 cm 2 , Is 1/2 = 4.706 mA s 1/2 , F = 96 485C mol −1 , C 0 -Co 2+ = 0.071 mol L −1 and C 0 -Fe 2+ = 0.036 mol L −1 , n = 2, The nucleation mode of Co 2+ and Fe 2+ at the deposition potential can be obtained by selecting different points from the stages of chronoamperometric curves and tting them according to eqn ( 4) and ( 6). 18 Instantaneous nucleation:…”

“…Table 5 shows that the tting degree of I(t) − t 1/2 is better than the tting degree of I(t) − t 3/2 at any potential, which indicates that the nucleation mechanism of Co 2+ and Fe 2+ on the silicon steel plate is instantaneous nucleation. 18 3.4.3. AC impedance testing.…”