Creating Excess Electrons at the Anatase TiO2(101) Surface



Payne, DT, Zhang, Y, Pang, CL ORCID: 0000-0002-5222-9734, Fielding, HH and Thornton, G
(2017) Creating Excess Electrons at the Anatase TiO2(101) Surface. TOPICS IN CATALYSIS, 60 (6-7). pp. 392-400.

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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.

Item Type: Article
Uncontrolled Keywords: TiO2, Anatase, Defect creation, Hydroxyl, Water, Excess electrons
Depositing User: Symplectic Admin
Date Deposited: 07 Feb 2019 16:14
Last Modified: 19 Jan 2023 01:04
DOI: 10.1007/s11244-016-0706-8
Open Access URL: https://doi.org/10.1007/s11244-016-0706-8
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3032467