COMPARATIVE DFT STUDIES OF CATION ADSORPTION ON CORUNDUM-TYPE

Interfaces between water and oxide surfaces play key roles in many applications and natural phenomena. Surfaces that exist under UHV conditions often do not persist under operational or hydrated conditions. As such, a great deal of effort has been given to characterizing metal oxide surface and interface structures. Yet a persistent barrier to solving a wide range of research problems is the current lack of molecular-level understanding about reactions at solid-water interfaces. We present results of a series of density functional theory (DFT) studies comparing the bonding strength and mechanisms of cation adsorption on hydrated alumina and hematite surfaces. Comparisons with and interpretation of experimental sorption results are made. By considering varying cation identity and surface composition, we are able to cast our results as rules governed by underlying chemical and physical properties.