Solvated ions as defects in liquid water: A first-principles perspective

ORAL

Abstract

Understanding the electronic properties of solvated ions is crucial in order to control and engineer aqueous electrolytes for a wide variety of emerging energy and environmental technologies, including photocatalytic water splitting. In this talk, we present a strategy to evaluate electronic energy levels of simple solvated ions in aqueous solutions, using a combination of first-principles molecular dynamics simulations and many-body perturbation theory within the GW approximation. We considered CO$_3^{2-}$, HCO$_3^{-}$, NO$_3^{-}$, NO$_2^{-}$ ions and we show that by analogy to defects in semiconductors, these solvated ions may be classified as deep or shallow defects in liquid water. In particular CO$_3^{2-}$ and NO$_2^{-}$ ions behave as shallow defects, while HCO$_3^{-}$ and NO$_3^{-}$ as deep ones. We also show that the inclusion of many-body corrections constitutes significant improvement over conventional density functional theory calculations, yielding satisfactory agreement with photoemission experiments.

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Authors

  • Eric Schwegler

    Lawrence Livermore Natl Lab

  • Tuan Anh Pham

    Lawrence Livermore Natl Lab

  • Marco Govoni

    University of Chicago, Institute for Molecular Engineering, University of Chicago, Institute for Molecular Engineering-The University of Chicago, and Argonne National Laboratory, Institute for Molecular Engineering, University of Chicago and Argonne National Laboratory, Institute for Molecular Engineering, University of Chicago & Argonne National Laboratory

  • Giulia Galli

    Institute for Molecular Engineering, University of Chicago, University of Chicago, Institute for Molecular Engineering, the University of Chicago, Univ of Chicago, Institute for Molecular Engineering University of Chicago, Institute for Molecular Engineering-The University of Chicago, and Argonne National Laboratory, Institute for Molecular Engineering, The University of Chicago, Institute for Molecular Engineering, University of Chicago & Argonne National Laboratory