Electrodeposition of the Protective and Decorative Copper Coatings from Low Concentrated Nitrate Electrolytes

摘要

Polarization and spectrophotometric investigations of the copper electrodeposition have been performed by low concentration nitrate electrolytes in the presence of organic compounds such as Trilon B, acetic, tartaric and citric acids. The modeling of the ions' states in the bulk electrolyte showed that Trilon B dominates in the form of its anion complex, unlike the carboxylic acids that are mostly present in their neutral forms. It is shown that, in the presence of Trilon B, copper ions discharge is preceded by the chemical reaction taking place in the bulk of the solution, whereas the addition of acetic, tartaric and citric acids leads to the formation of an adsorption layer on the surface of the cathode. Glossy copper galvanocoatings obtained from nitrate electrolytes are explained by the formation of the mixed complexes of Cu~(2+) with admixtures and ammonium ions in the double electric layer.