Kinetics of Zn cathodic deposition in alkaline zincate solution

Abstract

Kinetic parameters of the electrode reactions were measured by investigating steady-state current-potential behaviors. The Tafel slopes of cathodic and anodic processes are −0.113 8 V and −0.041 18 V, the anodic and cathodic apparent transfer coefficients are 0.519 3 and 1.435 2, respectively, and the stoichiometric number of rate-determining step is 1. The theoretical kinetics equation of electrode reaction was deduced, from which the dynamic parameters can be calculated as follows: the cathodic and anodic Tafel slopes are −0.118 V and −0.039 4 V, respectively, consisting with the experimental values. Finally, the correctness of the mechanism was further demonstrated using apparent transfer coefficient according to the electrochemical dynamic equation of multi-electron reaction.

Keywords

alkaline zincate / Zn cathodic deposition / kinetics / apparent transfer coefficient

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