Computational Investigations of the Water Structure at the α-Al2O3(0001)-Water Interface

The & alpha;-Al2O3(0001)-water interfaceis investigated using ab initio molecular dynamics(AIMD) simulations. The spectral signatures of the vibrational sumfrequency generation (vSFG) spectra of OH stretching mode for watermolecules at the interface are related to the interfacial water orientation,hydrogen bond network, and water dissociation process at differentwater/alumina interfaces. Significant differences are found betweenalumina surfaces at different hydroxylation levels, namely, Al-terminatedand O-terminated & alpha;-Al2O3(0001). By calculatingthe vibrational sum frequency generation spectrum and its imaginarycomponent from AIMD results, the structure of interfacial waters aswell as the termination of alumina slab are related to the spectralsignatures of vSFG data.