title: Interaction between water and defective silica surfaces.
abstract: We use the density functional theory method to study dry (1 × 1) α-quartz (0001) surfaces that have Frenkel-like defects such as oxygen vacancy and oxygen displacement. These defects have distinctively different effects on the water-silica interface depending on whether the adsorbent is a single water molecule, a cluster, or a thin film. The adsorption energies, bonding energies, and charge transfer or redistributions are analyzed, from which we find that the existence of a defect enhances the water molecule and cluster surface interaction by a large amount, but has little or even negative effect on water thin film-silica surface interaction. The origin of the weakening in film-surface systems is the collective hydrogen bonding that compromises the water-surface interaction in the process of optimizing the total energy. For clusters on surfaces, the lowest total energy states lower both the bonding energy and the adsorption energy.
authors.affiliation: Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Yun-Wen
authors.initials: YW
authors.lastname: Chen
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Cheng