Water adsorption on r‐TiO2(110): Presence of a well‐defined (1 × 1)‐structure as evidenced by He‐atom scattering

The adsorption of water on r-TiO2(110) has been investigated with thermal desorption spectroscopy (TDS) and helium atom scattering. Conventional TDS using a mass spectrometer and He-TDS monitoring reflected He beam intensity consistently show the existence of a structurally well-defined monolayer as well as a highly ordered second layer of water and a disordered multilayer phase. He diffraction patterns recorded along the high symmetry [001], , and directions reveal a well-ordered superstructure with (1 × 1) symmetry, providing strong evidence for the absence of a partially dissociated monolayer on the perfect parts of the substrate. No changes in the diffraction patterns are observed after irradiation with UV-light.