Defect-Induced Water Bilayer Growth on Anatase TiO2(101)
Artikel i vetenskaplig tidskrift, 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.

Water adsorption

Anatase

photoelectron spectroscopy

Titania

surface science

oxide surface

Författare

Andreas Schaefer

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Per-Anders Carlsson Group

V. Lanzilotto

Uppsala universitet

U. Cappel

Uppsala universitet

Kungliga Tekniska Högskolan (KTH)

Per Uvdal

Lunds universitet

Anne Borg

Norges teknisk-naturvitenskapelige universitet

Anders Sandell

Uppsala universitet

Langmuir

0743-7463 (ISSN) 1520-5827 (eISSN)

Vol. 34 37 10856-10864

Ämneskategorier

Fysikalisk kemi

Materialkemi

Vattenbehandling

DOI

10.1021/acs.langmuir.8b01925

Mer information

Senast uppdaterat

2018-10-18