This work focuses on the electrochemical behavior of zinc in 0.01 M NaOH solution. The results include determination of the semiconductor behavior of the passive film, as well as the estimation of its thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics, where the oxygen vacancies and interstitials preponderated. Moreover, it was shown that the calculated donor density increases with increasing formation potential. Electrochemical impedance spectroscopy results indicated that the thickness of the passive film was increased linearly with increasing formation potential. The results showed that increasing the formation potential offer worse conditions for forming the passive films with lower protection behavior, due to the growth of a much thicker and higher defective films.
