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 electrodeposition of Ni ions to form a compact Ni deposit in choline chloride-ethylene glycol, ChCl-EG (Ethaline) as a deep eutectic solvent (DES) is considered since an Ethaline plating bath for deposition of Ni coatings from Ni powder has not been reported. Ni speciation in the plating bath in 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, together with the morphology of the deposit. The deposition rate of both systems (NiCl2 and Ni powder) under identical conditions was measured at 90 °C. It was shown that the Ni deposits formed in the presence of iodine had a different structure from those formed from NiCl2 in pure DES. It is suggested that this is due to changes in the interaction of chloride and iodine ions together 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
Rasan Sarbast Faisal

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

ISSN
1745-9192

Publish Date: 2-Dec-2025