Abstract
Anodic dissolution mechanisms of zinc in citric acid/sodium hydroxide buffer solutions (pH2-5) and sodium carbonate/sodium hydrogen carbonate buffer solutions (pH9-10) have been investigated using electrochemical techniques. The reaction parameters were obtained from the polarization curves of zinc, and the following dissolution mechanism was proposed.
Zn+OH−=ZnOHads+e−
Zn+ZnOHads+OH−→ZnOHads+ZnOH++2e−
ZnOH+=Zn2++OH−
An electrochemical quartz crystal microbalance (EQCM) was applied, and the mass change of zinc electrode was determined simultaneously with the measurement of polarization curve. Furthermore, the influences of chloride and sulfate ions on the anodic behavior of zinc were discussed.
