Metal coatings based on complex compounds of copper (II) with organophosphorus complexones

Abstract

An important problem of the metal coatings formation processes is the choice of complexing agents for the preparation of process solutions. Nowadays a large number of complex electrolytes for metal deposition have been developed and introduced into production. However, the search for new, more efficient ligands allowing to obtain coatings with specified functional properties is an urgent task and constantly attracts the attention of researchers. To optimize and develop promising technological processes for producing metal coatings, experimental studies of electrode reactions in complex electrolytes are necessary. From this point of view, the study of electrochemical behavior of complex copper (II) ions with hydroxyethylidene diphosphonic acid is of considerable theoretical and practical interest. Oxyethylidene diphosphonic acid forms stable complexonates with copper (II) ions, the compound is non-toxic and available on an industrial scale. To study the kinetics and mechanism of copper deposition from solutions based on copper (II) complex compounds with hydroxyethylidene diphosphonic acid we used modulation spectroscopy of electroreflection, chronopotentiometry, and a rotary disk electrode. The paper shows that with increasing pH of the solution, the overpotential of copper increases due to a change in the composition of the discharging complex ion and adsorption phenomena on the electrode surface. In strongly alkaline solutions, the discharge of complex ions flows from the adsorbed state.