Sn nucleation and growth from Sn(II) dissolved in ethylene glycol: Electrochemical behavior and temperature effect

Abstract

Thermodynamic and kinetic aspects of Sn nucleation and growth processes onto a glassy carbon electrode from SnCl₂·2H₂O dissolved in ethylene glycol solutions were studied. Typical reduction and oxidation peaks observed in voltammograms have demonstrated the capability of ethylene glycol solutions to electrodeposit Sn. The temperature-dependence of diffusion coefficient values derived from potentiodynamic and potentiostatic studies helped to determine and validate estimations of the activation energy for Sn(II) bulk diffusion. Chronoamperometric results have identified that, the suitable model to describe the early stage of Sn electrodeposition could be composed of Sn three-dimensional nucleation and diffusion-controlled growth and water reduction contributions, which was duly validated by theoretical and experimental approaches. From the model, typical kinetic parameters such as the nucleation frequency of Sn (A), number density of Sn nuclei (N₀), and diffusion coefficient of Sn(II) ions (D), were determined. The presence of Sn nuclei with excellent quality and their structures were verified using SEM, EDX, and XRD techniques.