First Principles Determination of the Potential-of-Zero-Charge in an Alumina-Coated Aluminum/Water Interface Model for Corrosion Applications

The surfaces of most metals immersed in aqueous electrolytes have a several-nanometer-thick oxide/hydroxide surface layer. This gives rise to the existence both metal∣oxide and oxide∣liquid electrotlyte interfaces, makes it challenging correlate atomic length-scale structures with electrochemical properties such potential-of-zero-charge (PZC). PZC has been shown be correlated onset potential for pitting corrosion. In this work, we conduct large-scale Density Functional Theory ab initio molecular dynamics calculate Al(111)∣ γ -Al 2 O 3 (110)∣ water double-interface model within context aluminum By partitioning multiple interfaces involved into binary components additive contributions overall work function voltage, predict −1.53 V vs SHE model. We also orbital energy levels defects like oxygen vacancies oxide, which are critical parameters theories associated that Fermi level at lies above impurity defect vacancies, therefore uncharged PZC. From estimate, voltage needed create net postive charges flatband approximation.