Electrochemical Study of Copper(II) Reduction from Ammonia-Chloride Solutions

Abstract

The mechanism of CuII reduction from CuII-NH3-Cl--H2O solutions was found to involve two steps, the kinetics of which were determined, as functions of solution composition and temperature, by voltammetry and chronoamperometry. Chronoamperometric measurements indicated that adsorption strongly affected the overall copper(II) reduction process, which involved three-dimensional nucleation and growth that was diffusion controlled at sufficiently negative overpotentials. Scanning electron micrographs of copper electrodeposits showed the effect of adsorption on their morphology.