The adsorption of water on Pt(111) studied by irreflection and UV-photoemission spectroscopy

IR-reflection spectroscopy (IRS) under grazing incidence and UV-photoemission (UPS) with Hel and Hell radiation were used to study the adsorption of D₂O and H₂O, respectively, on Pt(111) under UHV conditions. In IRS three different vibrational bands in the OD stretch region yield information about the orientation of hydrogen-bonded water molecules and the formation of water clusters. Initially formed water multimers grow to clusters and finally build up multilayers. From UPS the adsorption of molecular water in the whole coverage range is confirmed. Both UPS and IRS show that the water molecules in the “first layer” are bound through their oxygen end to the surface.