Chemical Identification at the Solid-Liquid Interface

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Hagen Soengen
  • Christoph Marutschke
  • Peter Spijker
  • Eric Holmgren
  • Ilka Hermes
  • Ralf Bechstein
  • Stefanie Klassen
  • John Tracey
  • Adam Foster

  • Angelika Kuehnle

Research units

  • Johannes Gutenberg University Mainz
  • University of Rochester
  • Kanazawa University

Abstract

Solid-liquid interfaces are decisive for a wide range of natural and technological processes, including fields as diverse as geochemistry and environmental science as well as catalysis and corrosion protection. Dynamic atomic force microscopy nowadays provides unparalleled structural insights into solid-liquid interfaces, including the solvation structure above the surface. In contrast, chemical identification of individual interfacial atoms still remains a considerable challenge. So far, an identification of chemically alike atoms in a surface alloy has only been demonstrated under well-controlled ultrahigh vacuum conditions. In liquids, the recent advent of three-dimensional force mapping has opened the potential to discriminate between anionic and cationic surface species. However, a full chemical identification will also include the far more challenging situation of alike interfacial atoms (i.e., with the same net charge). Here we demonstrate the chemical identification capabilities of dynamic atomic force microscopy at solid-liquid interfaces by identifying Ca and Mg cations at the dolomite water interface. Analyzing site-specific vertical positions of hydration layers and comparing them with molecular dynamics simulations unambiguously unravels the minute but decisive difference in ion hydration and provides a clear means for telling calcium and magnesium ions apart. Our work, thus, demonstrates the chemical identification capabilities of dynamic AFM at the solid-liquid interface.

Details

Original languageEnglish
Pages (from-to)125-129
Number of pages5
JournalLangmuir
Volume33
Issue number1
Publication statusPublished - 20 Jan 2017
MoE publication typeA1 Journal article-refereed

    Research areas

  • ATOMIC-FORCE MICROSCOPY, MOLECULAR-DYNAMICS SIMULATIONS, AQUEOUS-SOLUTION, CALCIUM-CARBONATE, SURFACE, WATER, RESOLUTION, HYDRATION, FIELD, SPECTROSCOPY

ID: 10822712