Photodesorption and Trapping of Molecular Oxygen at the TiO(110)-Water Ice Interface
By means of temperature programmed desorption (TPD), static secondary ion mass spectroscopy (SSIMS), and electron loss spectroscopy (EELS) we have investigated further the states of oxygen adsorbed on rutile TiO. Previous work has shown that annealing the (110) surface in vacuum produces isolated bridging oxygen vacancies are intimately connected with molecular and dissociative oxygen adsorption channels. We find that at 115K illumination of the oxygen exposed surface with 4.1eV photons results in photodesorption of the oxygen associated with a TPD state centered on 410 K, in contrast to the remaining oxygen destined for a dissociative channel. An unusual effect of water overlayers on the photochemical properties of the O/TiO(110) system is explored. For thick overlayers, it is possible to generate via UV irradiation a previously unobserved oxygen TPD state. Evidence is presented for this new Ox TPD state originating from the photolysis of an O-water adduct.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 15007652
- Report Number(s):
- PNNL-SA-33618; KP1301020
- Journal Information:
- Journal of Physical Chemistry B, Journal Name: Journal of Physical Chemistry B Journal Issue: 18 Vol. 105
- Country of Publication:
- United States
- Language:
- English
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