Cobalt Electroplating in Choline Chloride-ethylene Glycol: A Comparative Study

Abstract

In this work, cobalt electroplating from homogeneous oxidation of cobalt powder via iodine as a chemical oxidizing agent and from CoCl2·6H2O in choline chloride-ethylene glycol electrolytic bath was carried out at 90 °C. As relatively high temperature and corrosion resistive coating material, cobalt electroplating was performed. A number of electrochemical, spectroscopic and microscopic techniques, such as, cyclic voltammetry (CV), chronocoulometry, UV-visible spectroscopy and scanning electron microscopy (SEM) were used in fabrication and characterizations of the electroplated cobalt. The progressive nucleation mechanism is followed in case of cobalt electroplating using cobalt powder in the presence of iodine. The mirror-like surface (i.e., smooth surface) surface has been obtained when cobalt powder utilized with the aid of iodine as shown in the SEM images. The effectiveness of the existence of iodine and cobalt powder was evidenced from chronocoulometry in which huge number of charge was released during the electrochemical course.

Keywords

• electroplating
• cobalt powder
• iodine
• deep eutectic solvent