Quasiparticle interfacial level alignment of highly hybridized frontier levels : H2O on TiO2(110)
Migani, Annapaola (Institut Català de Nanociència i Nanotecnologia)
Mowbray, Duncan J. (Universidad del País Vasco. Departamento de Física de Materiales)
Zhao, Jin (University of Science and Technology of China)
Petek, Hrvoje (University of Pittsburgh. Department of Physics and Astronomy)

Data:	2015
Resum:	Knowledge of the frontier levels' alignment prior to photoirradiation is necessary to achieve a complete quantitative description of HO photocatalysis on TiO(110). Although HO on rutile TiO(110) has been thoroughly studied both experimentally and theoretically, a quantitative value for the energy of the highest HO occupied levels is still lacking. For experiment, this is due to the HO levels being obscured by hybridization with TiO(110) levels in the difference spectra obtained via ultraviolet photoemission spectroscopy (UPS). For theory, this is due to inherent difficulties in properly describing many-body effects at the HO-TiO(110) interface. Using the projected density of states (DOS) from state-of-the-art quasiparticle (QP) GW, we disentangle the adsorbate and surface contributions to the complex UPS spectra of HO on TiO(110). We perform this separation as a function of HO coverage and dissociation on stoichiometric and reduced surfaces. Due to hybridization with the TiO(110) surface, the HO 3a and 1b levels are broadened into several peaks between 5 and 1 eV below the TiO(110) valence band maximum (VBM). These peaks have both intermolecular and interfacial bonding and antibonding character. We find the highest occupied levels of HO adsorbed intact and dissociated on stoichiometric TiO(110) are 1. 1 and 0. 9 eV below the VBM. We also find a similar energy of 1. 1 eV for the highest occupied levels of HO when adsorbed dissociatively on a bridging O vacancy of the reduced surface. In both cases, these energies are significantly higher (by 0. 6 to 2. 6 eV) than those estimated from UPS difference spectra, which are inconclusive in this energy region. Finally, we apply self-consistent QPGW (scQPGW1) to obtain the ionization potential of the HO-TiO(110) interface.
Ajuts:	Ministerio de Economía y Competitividad FIS2012-37549-C05-02 Ministerio de Economía y Competitividad RYC-2011-09582 Ministerio de Economía y Competitividad JCI-2010-08156 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-301
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Publicat a:	Journal of chemical theory and computation, Vol. 11, Issue 1 (January 2015) , p. 239-251, ISSN 1549-9626

DOI: 10.1021/ct500779s

Postprint 13 p, 7.1 MB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Institut Català de Nanociència i Nanotecnologia (ICN2)
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