ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Temperature dependence of deposition behavior and corrosion resistance of zinc coatings electroplated on copper substrates from ethaline electrolyte

Fan Jiang, Tianqi Zhu, Hongyan Wu, and Shaofu Li

Institute of Advanced Materials and Flexible Electronics (IAMFE), School of Chemistry and Materials Science, Nanjing University of Information Science and Technology, Nanjing, China

E-mail: jiangfan1109@163.com

Received: 19 November 2022  Accepted: 21 January 2023

Abstract:

Electrodeposition of zinc (Zn) coatings on copper (Cu) substrates was conducted from choline chloride–ethylene glycol-based deep eutectic solvent under the temperatures varying from 323 to 343 K. The electrochemical behavior of Zn ions on Cu electrodes at different temperatures was studied through cyclic voltammetry and chronoamperogram testing. The obtained results illustrate that the electrodeposition of Zn coatings is a diffusion-controlled quasi-reversible process with an instantaneous two-dimensional nucleation and growth mechanism. The crystal structure and chemical composition analysis demonstrates that the electrodeposition from ChCl–EG–ZnCl₂ system is an effective strategy to achieve a Zn coating with high crystallinity and purity. The surface morphological analysis further reveals that the electroplated coatings are stacks of flake Zn grains. The dependence of the deposition behavior and quality of electroplated Zn coatings on temperature was studied systematically. The growth behavior of Zn grains is enhanced with increasing the temperature, but too high a temperature inevitably leads to the undesired coarsen microstructure instead. On the basis of the polarization curves and EIS testing results, the temperature was optimized at 333 K to obtain a Zn coating with superior corrosion resistance in 3.5 wt% NaCl solution to that of Zn coatings electroplated at other conditions.

Keywords: Zinc coating; Electrodeposition; Nucleation–growth; Deep eutectic solvent; Corrosion

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02697-4

Chemical Papers 77 (6) 3201–3212 (2023)