Alumina(0001)/water interface structure and infrared spectra from first-principles molecular dynamics simulations

ORAL

Abstract

Knowledge of the interaction of water with solid oxide surfaces is of fundamental importance for the stability of solid oxides in aqueous environments. We studied the atomic structure and infrared (IR) spectra of the alumina(0001)/water interface, using molecular dynamics simulations and the Qbox code. We found that the structural properties of the interface, as described within the generalized gradient approximation, are in good agreement with synchrotron X-ray scattering experiments. In addition, a detailed analysis of the computed IR spectra of interfacial water reveals two types of water molecules at the solid-liquid interface: one type participating in strong ``ice-like'' hydrogen bonding with the oxide surface, and one type of water molecules involved in weak ``liquid-like'' hydrogen bonding at the interface. Our results provide a molecular interpretation of the ``ice-like'' and ``liquid-like'' peaks observed in sum-frequency vibrational spectroscopy experiments.

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Authors

  • Eric Schwegler

    Lawrence Livermore National Laboratory, LLNL

  • Tuan Anh Pham

    Department of Chemistry, University of California Davis, Lawrence Livermore National Laboratory and Department of Chemistry UC Davis, Department of Chemistry UC Davis and Lawrence Livermore National Laboratory, Department of Chemistry, University of California, Davis, University of California, Davis, CA

  • Patrick Huang

    Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory

  • Giulia Galli

    Department of Chemistry, University of California Davis, Department of Chemistry, Department of Physics, University of California, Davis, University of California - Davis, Department of Chemistry and Department of Physics UC Davis, University of California, Davis, Department of Chemistry and Department of Physics, University of California, Davis, UC Davis, Department of Chemistry and Department of Physics, UC Davis, University of California, Davis, CA