First-principles modeling of layer-defect of Al2O3 surface eroded by H2O and Cl−

Abstract

First-principles calculations have been performed on the layer-defect Al2O3 surface to model the interaction and erosion by water molecules (H2O) and chloride ions (Cl−). The results evidence that for the Al-defect surface, prefer to react with H2O and Cl−, which not be found for O-defect surface systems. For the adsorption energy and binding energy calculations, the Al-defect surface has larger value than O-defect surface. The DOS results show that the hydrolysis reactions of the first adsorbed layer of H2O only happen on the Al-defect surface because of the strong orbital hybridization between O atoms and Cl−. And when low concentrations of Cl− reach the surface, they prefer to erode the Al-defect surface with producing Al-Cl compounds, while they prefer to interact with H2O upon the O-defect surface. Furthermore, the electron density and population data are calculated for more information to analysis the effect of surface corrosion by Cl−.