Molecular dynamics analysis of NaOH aqueous solution surface and the sum frequency generation spectra: Is surface OH- detected by SFG spectroscopy?

Takako Imamura, Tatsuya Ishiyama, Akihiro Morita

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We elucidated the phase-sensitive sum frequency generation (SFG) spectrum of NaOH aqueous solution by molecular dynamics simulation. The MD analysis reproduced the effects of NaOH on the imaginary χ(2) spectrum, characterized with a positive (upward) shift in the amplitude in midfrequency region (3300-3600 cm-1) and a negative (downward) shift in low frequency (3000-3200 cm-1). We found that the positive shift is a consequence of electric double layers, while the negative shift is attributed to the first solvation shell of OH-. The latter mechanism generally holds for electrolyte solutions, though it becomes conspicuous for the NaOH solution in the low-frequency tail region. These perturbation mechanisms evidence that OH- at the surface is fully hydrated and not preferentially exposed to the surface.

Original languageEnglish
Pages (from-to)29017-29027
Number of pages11
JournalJournal of Physical Chemistry C
Volume118
Issue number50
DOIs
Publication statusPublished - 2014 Dec 18

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Molecular dynamics analysis of NaOH aqueous solution surface and the sum frequency generation spectra: Is surface OH<sup>-</sup> detected by SFG spectroscopy?'. Together they form a unique fingerprint.

  • Cite this