Insights into the geometry, stability and vibrational properties of OH groups on -Al2O3, TiO2-anatase and MgO from DFT calculations

The properties of hydroxyl groups on -Al2O3, TiO2-anatase and MgO are rationalized by Density Functional Theory calculations. Oxide ionicity is found to be determinant in the water/oxide interaction strength when dissociation of H2O occurs, and in the bridging ability of monocoordinated surface OH groups. For a hydroxyl, being the hydrogen bond donor, acceptor or having an isolated nature is found to be the most important parameter governing the O-H stretching frequency.