Effect of Different Acid Anions on Kinetics of the Formation and Dissolution Behavior of Anodic Zirconium Oxide

Effects of sulfuric acid (H₂SO₄), phosphoric acid (H₃PO₄), nitric acid (HNO₃), and hydrochloric acid (HCl) on kinetics of the formation and dissolution behavior of zirconium oxide (ZrO₂) were studied using the impedance, potential, and galvanostatic techniques. The oxide film did not form galvanostatically in 1 M HCl because of dissolution simultaneously with formation, while the rate of formation in other acids decreased in the order: H₂SO₄ > H₃PO₄ > HNO₃. Impedance and potential measurements reflected the same dissolution process, with the rate of formation decreasing in the order: HCl > HNO₃ > H₃PO₄ > H₂SO₄. The theory of anodization was applied, and data were collected for reciprocal capacity, electrolytic parameters, and field strength. Activation energy during the oxide film formation was calculated as 4.99 kJ/mol. A general treatment was applied using three models under galvanostatic conditions.