Defect-Induced Water Bilayer Growth on Anatase TiO2(101)

Research output: Contribution to journalArticle

Abstract

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.

Details

Authors
  • A. Schaefer
  • V. Lanzilotto
  • U. B. Cappel
  • P. Uvdal
  • A. Borg
  • A. Sandell
Organisations
External organisations
  • Chalmers University of Technology
  • Uppsala University
  • Norwegian University of Science and Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Materials Chemistry
Original languageEnglish
Pages (from-to)10856-10864
Number of pages9
JournalLangmuir
Volume34
Issue number37
Publication statusPublished - 2018
Publication categoryResearch
Peer-reviewedYes