The influence of substituted aromatic aldehydes on Zn-Mn alloy electrodeposition

Abstract

Additives are necessary in the electrodeposition of Zn-Mn alloys at high current density, in order to reduce hydrogen evolution reaction and prevent dendrite formation. The influence of two aromatic aldehydes, 4-hydroxy-benzaldehyde and 3,4-dimethoxy-benzaldehyde, as the additives in Zn-Mn plating electrolyte, is examined in this work. The coatings characterization by scanning electron microscopy and X-ray energy dispersive spectroscopy, as well as the examination of additives effect by electrochemical methods, indicate a complex involvement of additive molecules in hydrogen evolution, as well as in Zn2+ and Mn2+ reduction. Consequently, the levelling action can be achieved and the chemical composition of the Zn-Mn alloy can be tailored, by adding the proper additive type and concentration in the plating electrolyte.