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Water Dissociation on Single Crystalline Anatase TiO2(001) Studied by Photoelectron Spectroscopy

Blomquist, Jakob LU ; Walle, L. E.; Uvdal, Per LU ; Borg, A. and Sandell, A. (2008) In Journal of Physical Chemistry C 112(42). p.16616-16621
Abstract
The adsorption of water on the anatase TiO2(001)-(4 x 1) surface is studied using synchrotron radiation-excited core level photoelectron spectroscopy. The coverage-dependent adsorption of water at low temperature is monitored and compared to the sequence obtained after heating of a water multilayer. Two adsorption phases of submonolayer coverage can be defined: Phase 1 consists only of dissociated water, observed as OH-groups. This phase is found at low coverage at low temperature (190 K) and is the only state of adsorbed water above similar to 230 K. The saturation coverage of phase 1 is consistent with dissociation on the 4-fold-coordinated Ti ridge atoms of the (4 x 1) surface reconstruction. Phase 2 is found at higher coverage, reached... (More)
The adsorption of water on the anatase TiO2(001)-(4 x 1) surface is studied using synchrotron radiation-excited core level photoelectron spectroscopy. The coverage-dependent adsorption of water at low temperature is monitored and compared to the sequence obtained after heating of a water multilayer. Two adsorption phases of submonolayer coverage can be defined: Phase 1 consists only of dissociated water, observed as OH-groups. This phase is found at low coverage at low temperature (190 K) and is the only state of adsorbed water above similar to 230 K. The saturation coverage of phase 1 is consistent with dissociation on the 4-fold-coordinated Ti ridge atoms of the (4 x 1) surface reconstruction. Phase 2 is found at higher coverage, reached at lower temperature. It consists of a mixture of dissociated and molecular water with a ratio of 1:1 at 170 K. The molecular water is found to bond to the hydroxyl groups. The hydroxyl coverage of phase 2 is approximately 2 times that of phase 1. The results suggest that the OH and H2O species of phase 2 are confined to the ridges of the surface. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry C
volume
112
issue
42
pages
16616 - 16621
publisher
The American Chemical Society
external identifiers
  • wos:000260129400071
  • scopus:55649108440
ISSN
1932-7447
DOI
10.1021/jp805664b
language
English
LU publication?
yes
id
b8de69c7-a2ef-4f54-adc1-795a3fc37baa (old id 1284661)
date added to LUP
2009-02-09 09:36:24
date last changed
2017-09-03 03:50:06
@article{b8de69c7-a2ef-4f54-adc1-795a3fc37baa,
  abstract     = {The adsorption of water on the anatase TiO2(001)-(4 x 1) surface is studied using synchrotron radiation-excited core level photoelectron spectroscopy. The coverage-dependent adsorption of water at low temperature is monitored and compared to the sequence obtained after heating of a water multilayer. Two adsorption phases of submonolayer coverage can be defined: Phase 1 consists only of dissociated water, observed as OH-groups. This phase is found at low coverage at low temperature (190 K) and is the only state of adsorbed water above similar to 230 K. The saturation coverage of phase 1 is consistent with dissociation on the 4-fold-coordinated Ti ridge atoms of the (4 x 1) surface reconstruction. Phase 2 is found at higher coverage, reached at lower temperature. It consists of a mixture of dissociated and molecular water with a ratio of 1:1 at 170 K. The molecular water is found to bond to the hydroxyl groups. The hydroxyl coverage of phase 2 is approximately 2 times that of phase 1. The results suggest that the OH and H2O species of phase 2 are confined to the ridges of the surface.},
  author       = {Blomquist, Jakob and Walle, L. E. and Uvdal, Per and Borg, A. and Sandell, A.},
  issn         = {1932-7447},
  language     = {eng},
  number       = {42},
  pages        = {16616--16621},
  publisher    = {The American Chemical Society},
  series       = {Journal of Physical Chemistry C},
  title        = {Water Dissociation on Single Crystalline Anatase TiO2(001) Studied by Photoelectron Spectroscopy},
  url          = {http://dx.doi.org/10.1021/jp805664b},
  volume       = {112},
  year         = {2008},
}