Electrodeposition Study of Ni Coatings on Copper from Choline Chloride-Based Deep Eutectic Solvents

Nickel was electrodeposited from choline chloride (ChCl)-based deep eutectic solvents (DESs) containing ethylene glycol (EG) and urea (U) on Cu substrate. The influence of the temperature and of DESs nature was evaluated. The diffusion coefficients of nickel varied from 2.2 × 10-9 to 3.7 × 10-8 cm2 s-1 for ChCl:2U and from 1.3 × 10-8 to 5.8 × 10-8 cm2 s-1 for ChCl:2EG with increasing temperature. The nucleation process of Ni on Cu at 70 °C was determined as instantaneous in ChCl:2EG and progressive in ChCl:2U using Scharifker and Hills model. The SEM characterization showed that with incr...