Journal article
Interfacial ionic 'liquids': connecting static and dynamic structures
Journal of physics. Condensed matter, v 27(3), pp 032101-032101
05 Dec 2014
PMID: 25475119
Abstract
It is well known that room temperature ionic liquids (RTILs) often adopt a charge-separated layered structure, i.e. with alternating cation- and anion-rich layers, at electrified interfaces. However, the dynamic response of the layered structure to temporal variations in applied potential is not well understood. We used in situ, real-time x-ray reflectivity to study the potential-dependent electric double layer (EDL) structure of an imidazolium-based RTIL on charged epitaxial graphene during potential cycling as a function of temperature. The results suggest that the graphene-RTIL interfacial structure is bistable in which the EDL structure at any intermediate potential can be described by the combination of two extreme-potential structures whose proportions vary depending on the polarity and magnitude of the applied potential. This picture is supported by the EDL structures obtained by fully atomistic molecular dynamics simulations at various static potentials. The potential-driven transition between the two structures is characterized by an increasing width but with an approximately fixed hysteresis magnitude as a function of temperature. The results are consistent with the coexistence of distinct anion- and cation-adsorbed structures separated by an energy barrier (∼0.15 eV).
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Details
- Title
- Interfacial ionic 'liquids': connecting static and dynamic structures
- Creators
- Ahmet Uysal - Chemical Science and Engineering Division , Argonne National Laboratory, Argonne, IL 60439, USAHua Zhou - Advanced Photon Source , Argonne National Laboratory, Argonne, IL 60439, USAGuang Feng - Vanderbilt University Department of Chemical and Biomolecular Engineering, Nashville, TN 37235, USASang Soo Lee - Chemical Science and Engineering Division , Argonne National Laboratory, Argonne, IL 60439, USASong Li - Vanderbilt University Department of Chemical and Biomolecular Engineering, Nashville, TN 37235, USAPeter T Cummings - Vanderbilt University Department of Chemical and Biomolecular Engineering, Nashville, TN 37235, USAPasquale F Fulvio - Chemical Sciences Division , Oak Ridge National Laboratory, Oak Ridge, TN 37831, USASheng Dai - Chemical Sciences Division , Oak Ridge National Laboratory, Oak Ridge, TN 37831, USAJohn K McDonough - Drexel University Department of Materials Science and Engineering & A J Drexel Nanomaterials Institute, Philadelphia, PA 19104, USAYury Gogotsi - Drexel University Department of Materials Science and Engineering & A J Drexel Nanomaterials Institute, Philadelphia, PA 19104, USAPaul Fenter - Chemical Science and Engineering Division , Argonne National Laboratory, Argonne, IL 60439, USA
- Publication Details
- Journal of physics. Condensed matter, v 27(3), pp 032101-032101
- Publisher
- IOP Publishing
- Number of pages
- 9
- Grant note
- Basic Energy Sciences (http://dx.doi.org/10.13039/100006151)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Materials Science and Engineering
- Web of Science ID
- WOS:000348493400001
- Scopus ID
- 2-s2.0-84921689003
- Other Identifier
- 991014969871304721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Physics, Condensed Matter