Copper electrodeposition from alanine alkaline baths. A microkinetic study

Abstract

In this study, we performed a detailed analysis of the reduction behaviour of copper-alanine complexes under alkaline conditions. We analyse and discuss how the four cathodic processes presented in cyclic voltammetry profiles behave as a function of the scan speed and of the mass transport conditions by means of rotating disk electrode. Hence, we propose two different pathways in the copper-alanine reduction. In addition, we perform a hydrodynamic investigation at different mass transport regimes. Hence, we interpret the current response as a function of the mass transport under the lens of the Langmuir-Hinshelwood mechanism. To this end, we provide the Langmuir adsorption constant of copper-alanine complexes on metallic copper, and the Langmuir-Hinshelwood heterogeneous rate constant for the reduction of copper-alanine complexes at different potentials and temperatures.