Original scientific paper

https://doi.org/10.5562/cca4174

Kinetic and Morphological Study of Zn Electrodeposition onto HOPG from Alkaline Aqueous Solutions

Luis Humberto Mendoza-Huizar orcid.org/0000-0003-2373-4624 ; Área Académica de Química. Ciudad del Conocimiento. Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo km. 4.5, CP. 42184 Mineral de la Reforma, Hidalgo, México *

* Corresponding author.

Abstract

In this study, we conducted an electrochemical analysis of the electrodeposition of Zn onto a highly oriented pyrolytic graphite (HOPG) electrode from an aqueous solution containing 0.01 M ZnSO₄ and 1 M (NH₄)₂SO₄ at pH 8 and 25 °C. Voltammetric studies indicate that, under our experimental conditions, Zn electrodeposition is an irreversible diffusion-controlled process. Potentiostatic study was used to determine kinetic parameters such as the number of active nucleation sites (N₀), and the nucleation rate (A), which exhibited a dependence on the applied potential. The morphology of the Zn deposits was examined using scanning electron microscopy (SEM). The results show that electrodeposition at lower potentials leads to rougher surfaces, likely due to increased hydrogen evolution, which interferes with the uniformity of Zn growth. In contrast, at more positive potentials, Zn deposits appeared more homogeneous, suggesting a more controlled nucleation and growth process with reduced proton reduction process.

Keywords

zinc; electrodeposition; HOPG; kinetic; HER; SEM

Hrčak ID:

332786

URI

https://hrcak.srce.hr/332786

Publication date:

28.6.2025.

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