Glutamate-based mildly alkaline electrolyte as a green and safe alternative for zinc plating

Abstract

The electrodeposition of Zn from a Zn-Glutamate electrolyte has been studied with the aim of developing a mild alkaline formulation using non-toxic components as a green and safe alternative for Zn plating industry. Cyclic and linear sweep voltammetry results show that the deposition occurs in 2 consecutive steps whereas the dissolution process involves a complex mechanism similar to other alkaline Zn plating baths previously studied. Addition of polyquaternium 2 and 7 modified these electrochemical processes and influenced the morphology and crystal orientation of Zn coatings. Although good quality deposits were successfully obtained in absence of additives, the combination of polyquaternium 7 and benzyl alcohol produced the best quality, fine-grained and smooth coatings due to a synergy between these compounds. Overall, results show that the proposed formulation allows deposition of good quality Zn coatings using a considerably less aggressive electrolyte with no toxic components.