UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Electron traps and their effect on the surface chemistry of TiO2 (110)

Papageorgiou, AC; Beglitis, NS; Pang, CL; Teobaldi, G; Cabailh, G; Chen, Q; Fisher, AJ; ... Thornton, G; + view all (2010) Electron traps and their effect on the surface chemistry of TiO2 (110). P NATL ACAD SCI USA , 107 (6) 2391 - 2396. 10.1073/pnas.0911349107.

Full text not available from this repository.


Oxygen vacancies on metal oxide surfaces have long been thought to play a key role in the surface chemistry. Such processes have been directly visualized in the case of the model photocatalyst surface TiO2 (110) in reactions with water and molecular oxygen. These vacancies have been assumed to be neutral in calculations of the surface properties. However, by comparing experimental and simulated scanning tunneling microscopy images and spectra, we show that oxygen vacancies act as trapping centers and are negatively charged. We demonstrate that charging the defect significantly affects the reactivity by following the reaction of molecular oxygen with surface hydroxyl formed by water dissociation at the vacancies. Calculations with electronically charged hydroxyl favor a condensation reaction forming water and surface oxygen adatoms, in line with experimental observations. This contrasts with simulations using neutral hydroxyl where hydrogen peroxide is found to be the most stable product.

Type: Article
Title: Electron traps and their effect on the surface chemistry of TiO2 (110)
DOI: 10.1073/pnas.0911349107
Keywords: photocatalysis, STM/STS, titania, water, molecular oxygen, TIO2(110), O-2, DISSOCIATION, ADSORPTION, DEFECTS, OXYGEN, WATER, 1ST-PRINCIPLES, TRANSITION, DIFFUSION
URI: http://discovery.ucl.ac.uk/id/eprint/168788
Downloads since deposit
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item