Aqueous redox chemistry and the electronic band structure of liquid water

Christopher Adriaanse, Jun Cheng, Vincent Chau, Marialore Sulpizi, Joost VandeVondele, Michiel Sprik*

*Corresponding author for this work

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

The electronic states of aqueous species can mix with the extended states of the solvent if they are close in energy to the band edges of water. Using density functional theory-based molecular dynamics simulation, we show that this is the case for OH- and Cl-. The effect is, however, badly exaggerated by the generalized gradient approximation leading to systematic underestimation of redox potentials and spurious nonlinearity in the solvent reorganization. Drawing a parallel to charged defects in wide gap solid oxides, we conclude that misalignment of the valence band of water is the main source of error turning the redox levels of OH- and Cl- in resonant impurity states. On the other hand, the accuracy of energies of levels corresponding to strongly negative redox potentials is acceptable. We therefore predict that mixing of the vertical attachment level of CO2 and the unoccupied states of water is a real effect.

Original languageEnglish
Pages (from-to)3411-3415
Number of pages5
JournalThe Journal of Physical Chemistry Letters
Volume3
Issue number23
DOIs
Publication statusPublished - 6 Dec 2012

Keywords

  • emission-spectroscopy
  • energy
  • density
  • semiconductors
  • metals
  • models

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