Voltammetric and morphological characterization of copper electrodeposition from non-cyanide electrolyte

The electrodeposition of copper onto AISI 1010 steel using an alkaline electrolyte based on glycerol has been studied. The influence of NaOH concentration and the addition of sulfate as supporting electrolyte were investigated by voltammetric techniques. For a NaOH concentration greater than or equal to 0.6 M the plating bath was stable and immersion deposition onto steel was avoided. Voltammetric studies and SEM analysis indicated that the reduction process occurs through two different copper(II) species. The copper films were golden in colour, even in the high hydrogen evolution region, indicating that glycerinate anions prevent the copper deposits becoming darker. The presence of the sulfate anions affected the morphology of the copper films, acting as brighteners.