jp068606i_si_001.pdf (35.38 kB)
The Nature of Water Nucleation Sites on TiO2(110) Surfaces Revealed by Ambient Pressure X-ray Photoelectron Spectroscopy
journal contribution
posted on 2007-06-14, 00:00 authored by Guido Ketteler, Susumu Yamamoto, Hendrik Bluhm, Klas Andersson, David E. Starr, D. Frank Ogletree, Hirohito Ogasawara, Anders Nilsson, Miquel SalmeronX-ray photoelectron spectroscopy at ambient conditions of pressure (up to 1.5 Torr) and temperature (265 K
< T < 800 K) was used to study the adsorption of water on rutile TiO2(110) under conditions of thermodynamic
equilibrium. It was found that OH groups in bridging positions, normally present in small amounts due to
residual O-vacancies, act as nucleation sites for subsequent water adsorption. The adsorption enthalpy of
water binding to these sites is ∼70 kJ/mol, much stronger than that in the bulk liquid (45 kJ/mol). A model
is proposed that relates the structure of the oxide surface to its hydrophilic character.