The interaction of water with silica thin films grown on Mo(1 1 2)

The adsorption of water on ultrathin SiO2 films at low temperatures has been studied with metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy (UPS (HeI)). High-resolution electron energy-loss spectroscopy (HREELS), work function measurements (Δϕ), and temperature programmed desorption (TPD) were also utilized to study the interaction of water with silica. Evidence for molecular absorption of water on low- and high-defect silica surfaces is presented. The data are consistent with the growth of 3-D water clusters even at low coverage, i.e., the water–water hydrogen bonding is stronger than the water–silica interaction. No evidence for dissociation of water was found in contrast to previous UPS results.