Electrodeposition of Ni by oxidation of Ni powder using I2 in a choline chloride-ethylene glycol electrolyte

Abstract
Iodine is a strong oxidising agent for the dissolution of Ni powder to Ni ions. The subsequent\r\nelectrodeposition of Ni ions to form a compact Ni deposit in choline chloride-ethylene glycol,\r\nChCl-EG (Ethaline) as a deep eutectic solvent (DES) is considered since an Ethaline plating bath for\r\ndeposition of Ni coatings from Ni powder has not been reported. Ni speciation in the plating bath\r\nin the presence of (I2/I−) was established. This work aims to examine the deposition rate of Ni in\r\nthe presence of iodine and NiCl2 from a deep eutectic solvent containing iodine and NiCl2,\r\ntogether with the morphology of the deposit. The deposition rate of both systems (NiCl2 and Ni\r\npowder) under identical conditions was measured at 90 °C. It was shown that the Ni deposits\r\nformed in the presence of iodine had a di erent structure from those formed from NiCl2 in pure\r\nDES. It is suggested that this is due to changes in the interaction of chloride and iodine ions\r\ntogether with their ability to adsorb at the cathode surface. The deposition of Ni in the presence\r\nof iodine resulted in a uniform, nanocrystalline deposit.

Author
Dana Mohammad Khidhir

DOI
https://doi.org/10.1080/00202967.2025.2586493

ISSN

Publish Date: 2-Dec-2025