title: Structure of a model TiO2photocatalytic interface.
abstract: The interaction of water with TiO2is crucial to many of its practical applications, including photocatalytic water splitting. Following the first demonstration of this phenomenon 40 years ago there have been numerous studies of the rutile single-crystal TiO2(110) interface with water. This has provided an atomic-level understanding of the water-TiO2interaction. However, nearly all of the previous studies of water/TiO2interfaces involve water in the vapour phase. Here, we explore the interfacial structure between liquid water and a rutile TiO2(110) surface pre-characterized at the atomic level. Scanning tunnelling microscopy and surface X-ray diffraction are used to determine the structure, which is comprised of an ordered array of hydroxyl molecules with molecular water in the second layer. Static and dynamic density functional theory calculations suggest that a possible mechanism for formation of the hydroxyl overlayer involves the mixed adsorption of O2and H2O on a partially defected surface. The quantitative structural properties derived here provide a basis with which to explore the atomistic properties and hence mechanisms involved in TiO2photocatalysis.
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.|ESRF, 6 rue Jules Horowitz, F-38000 Grenoble cedex, France.
authors.forename: H
authors.initials: H
authors.lastname: Hussain
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: G
authors.initials: G
authors.lastname: Tocci
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: T
authors.initials: T
authors.lastname: Woolcot
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), Campus UAB, 08193 Bellaterra, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Torrelles
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: C L
authors.initials: CL
authors.lastname: Pang
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: D S
authors.initials: DS
authors.lastname: Humphrey
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: C M
authors.initials: CM
authors.lastname: Yim
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: D C
authors.initials: DC
authors.lastname: Grinter
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: G
authors.identifier: 0000-0002-8053-2132
authors.initials: G
authors.lastname: Cabailh
authors.affiliation: Department of Physics, University of Warwick, Gibbet Hill Road, Coventry C4 7AL, UK.
authors.forename: O
authors.identifier: 0000-0001-9004-9032
authors.initials: O
authors.lastname: Bikondoa
authors.affiliation: Corrosion and Protection Centre, School of Materials, The University of Manchester, Sackville Street, Manchester M13 9PL, UK.
authors.forename: R
authors.initials: R
authors.lastname: Lindsay
authors.affiliation: ESRF, 6 rue Jules Horowitz, F-38000 Grenoble cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Zegenhagen
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: A
authors.initials: A
authors.lastname: Michaelides
authors.affiliation: London Centre for Nanotechnology and Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK.
authors.forename: G
authors.initials: G
authors.lastname: Thornton