title: The structure of water at a Pt(111) electrode and the potential of zero charge studied from first principles.
abstract: The structure of a liquid water layer on Pt(111) has been studied by ab initio molecular dynamics simulations based on periodic density functional theory calculations. First the reliability of the chosen exchange-correlation function has been validated by considering water clusters, bulk ice structures, and bulk liquid water, confirming that the dispersion corrected RPBE-D3/zero functional is a suitable choice. The simulations at room temperature yield that a water layer that is six layers thick is sufficient to yield liquid water properties in the interior of the water film. Performing a statistical average along the trajectory, a mean work function of 5.01 V is derived, giving a potential of zero charge of Pt(111) of 0.57 V vs. standard hydrogen electrode, in good agreement with experiments. Therefore we propose the RPBE-D3/zero functional as the appropriate choice for first-principles calculations addressing electrochemical aqueous electrolyte/metal electrode interfaces.
authors.affiliation: Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany.
authors.forename: Sung
authors.initials: S
authors.lastname: Sakong
authors.affiliation: Helmholtz Institute Ulm (HIU), Electrochemical Energy Storage, 89069 Ulm, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Forster-Tonigold
authors.affiliation: Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Groß