The Role of Interstitial Sites in the Ti 3d Defect State in the Band Gap of Titania
| Autor: | Asger Blekinge-Rasmussen, Bjørk Hammer, E. Lægsgaard, Jonas Ø. Hansen, Flemming Besenbacher, Estephania Lira, Stefan Wendt, Georg K. H. Madsen, J. Matthiesen, Zhongshan Li, Phillip Sprunger |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Wendt, S, Sprunger, P, Lira, E, Madsen, G K H, Li, Z, Hansen, J Ø, Matthiesen, J, Blekinge-Rasmussen, A, Lægsgaard, E, Hammer, B & Besenbacher, F 2008, ' The Role of Interstitial Sites in the Ti 3d Defect State in the Band Gap of Titania ', Science, vol. 320, pp. 1755-1759 . https://doi.org/10.1126/science.1159846 |
| ISSN: | 1095-9203 0036-8075 |
| DOI: | 10.1126/science.1159846 |
| Popis: | Titanium dioxide (TiO 2 ) has a number of uses in catalysis, photochemistry, and sensing that are linked to the reducibility of the oxide. Usually, bridging oxygen (O br ) vacancies are assumed to cause the Ti 3d defect state in the band gap of rutile TiO 2 (110). From high-resolution scanning tunneling microscopy and photoelectron spectroscopy measurements, we propose that Ti interstitials in the near-surface region may be largely responsible for the defect state in the band gap. We argue that these donor-specific sites play a key role in and may dictate the ensuing surface chemistry, such as providing the electronic charge required for O 2 adsorption and dissociation. Specifically, we identified a second O 2 dissociation channel that occurs within the Ti troughs in addition to the O 2 dissociation channel in O br vacancies. Comprehensive density functional theory calculations support these experimental observations. |
| Databáze: | OpenAIRE |
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