Defect-Induced Water Bilayer Growth on Anatase TiO2(101)
Journal article, 2018

Preparing an anatase TiO2(101) surface with a high density of oxygen vacancies and associated reduced Ti species in the near-surface region results in drastic changes in the water adsorption chemistry compared to adsorption on a highly stoichiometric surface. Using synchrotron radiation excited photoelectron spectroscopy, we observe a change in the water growth mode, from layer-by-layer growth on the highly stoichiometric surface to bilayer growth on the reduced surface. Furthermore, we have been able to observe Ti3+ enrichment at the surface upon water adsorption. The Ti3+ enrichment occurs concomitant with effective water dissociation into hydroxyls with a very high thermal stability. The water bilayer on the reduced surface is thermally more stable than that on the stoichiometric surface, and it is more efficient in promoting further water dissociation upon heating. The results thus show how the presence of subsurface defects can alter the wetting mechanism of an oxide surface.

photoelectron spectroscopy

Anatase

Water adsorption

surface science

Titania

oxide surface

Author

Andreas Schaefer

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Per-Anders Carlsson Group

V. Lanzilotto

Uppsala University

U. Cappel

Uppsala University

Royal Institute of Technology (KTH)

Per Uvdal

Lund University

Anne Borg

Norwegian University of Science and Technology (NTNU)

Anders Sandell

Uppsala University

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 34 37 10856-10864

Subject Categories

Physical Chemistry

Materials Chemistry

Water Treatment

DOI

10.1021/acs.langmuir.8b01925

More information

Latest update

9/2/2019 8