Payne, DT;
Zhang, Y;
Pang, CL;
Fielding, HH;
Thornton, G;
(2017)
Creating Excess Electrons at the Anatase TiO2(101) Surface.
Topics in Catalysis
, 60
(6-7)
pp. 392-400.
10.1007/s11244-016-0706-8.
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Abstract
Excess electrons facilitate redox reactions at the technologically relevant anatase TiO2(101) surface. The availability of these electrons is related to the defect concentration at the surface. We present two-photon (2PPE, 3.10–3.54 eV) and ultraviolet (UPS, 21.2 & 40.8 eV) photoemission spectroscopy measurements evidencing an increased concentration of excess electrons following electron bombardment at room temperature. Irradiation-induced surface oxygen vacancies are known to migrate into the sub-surface at this temperature, quickly equilibrating the surface defect concentration. Hence, we propose that the irradiated surface is hydroxylated. Peaks in UPS difference spectra are observed centred 8.45, 6.50 and 0.73 eV below the Fermi level, which are associated with the 3σ and 1π hydroxyl molecular orbitals and Ti 3d band gap states, respectively. The higher concentration of excess electrons at the hydroxylated anatase (101) surface may increase the potential for redox reactions.
| Type: | Article |
|---|---|
| Title: | Creating Excess Electrons at the Anatase TiO2(101) Surface |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s11244-016-0706-8 |
| Publisher version: | http://dx.doi.org/10.1007/s11244-016-0706-8 |
| Language: | English |
| Additional information: | © The Author(s) 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
| Keywords: | TiO2, Anatase, Defect creation, Hydroxyl, Water, Excess electrons |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1532756 |
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