abstract
The interaction of xenon atoms with the TiO2(1 1 0) surface of rutile has been studied by density functional theory methods. Five different possible adsorption sites on the relaxed and clean TiO2(1 1 0) surface and on two different type of oxygen vacancies possible on this oxide substrate have been considered. In the case of the defect-free substrate, and when compared with a previous study concerning the adsorption of At atoms also on TiO2(1 1 0), the xenon atom, as a larger and easier polarizable species, is shown to have a deeper physisorption well, as expected. Likewise, Xe atoms prefer to be bounded to positions nearby the outermost titanium atoms as found previously for At. This is in agreement with most studies concerning rare gases adsorbed on transition metal surfaces. In the case of the reduced surfaces, it is found that the interaction is more favourable in the protruding rows. The interaction is dominated by dispersion forces and DFT + dispersion energies are 3.5-5 times larger than the non-corrected DFT values and Xe-surface distances are smaller. Finally, an interesting correlation is obtained for the calculated interaction energies and the Xe-Ti distance. (C) 2009 Elsevier B.V. All rights reserved.
keywords
GENERALIZED GRADIENT APPROXIMATION; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; OXYGEN VACANCIES; 1ST PRINCIPLES; BASIS-SET; PT(111); METAL
subject category
Chemistry; Physics
authors
Gomes, JRB; Ramalho, JPP; Illas, F
our authors
José R. B. Gomes
Principal Researcheracknowledgements
Financial support from FEDER, Portuguese Fundacao para a Ciencia e Tecnologia (FCT), HPC-Europa transnational programme, Conselho de Reitores das Universidades Portuguesas (CRUP), and Spanish Ministerio de Ciencia e Innovacion (MICCIN) through grants Programa Ciencia 2007, Accao E-43/08, FIS2008-02238 and HP2007-0042 is fully acknowledged. JRBG thanks also FCT for the grant (SFRH/BPD/11582/2002).