The polarization behaviour of zinc in alkaline solution has been investigated using atomic emission spectroelectrochemistry By independently measuring the oxidation rate of zinc (electrical current) and the rate of Zn2+ dissolution (partial elemental current) It is possible to calculate the amount of insoluble zinc cations produced at any instant Assuming the insoluble cations are present as a zinc oxide film the growth of this film as a function of potential and time was determined On the basis of kinetic evidence it was found that at least three forms of zinc based oxide/hydroxide films form during polarization experiments Type I oxide formation occurs when the metal/electrolyte interface becomes locally saturated with Zn2+ ions Type II oxide forms on the metal surface underneath the film of Type I oxide but has little inhibiting effect on zinc dissolution Type III oxide is produced in much smaller quantity and results in a transition to the passive state This may be due to a potential Induced transition of Type II -> Type III oxide (C) 2010 Elsevier Ltd All rights reserved