1
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Siinor L, Ers H, Pikma P. Another Piece of the Ionic Liquid's Puzzle: Adsorption of Cl - Ions. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:2722-2729. [PMID: 38379917 PMCID: PMC10877642 DOI: 10.1021/acs.jpcc.3c07991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 02/22/2024]
Abstract
Classical electrochemical and microscopy methods were used to characterize the interfacial processes of the adsorption of chloride ions from ionic liquids at the Bi(111) single crystal electrode. The mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate and 1-ethyl-3-methylimidazolium chloride was electrochemically characterized by using cyclic voltammetry and electrochemical impedance spectroscopy. In situ scanning tunneling microscopy images showed the formation of superstructures at the electrode's surface over an extended period of time. The specific adsorption of chloride ions reaches an equilibrium state in a more viscous ionic liquid medium slower than in aqueous and organic solvents. Capacitance values increase considerably (also depending on alternative current frequency) at the potential region, where the specific adsorption of chloride ions with partial charge transfer occurs.
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Affiliation(s)
- Liis Siinor
- Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu, Estonia
| | - Heigo Ers
- Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu, Estonia
| | - Piret Pikma
- Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu, Estonia
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2
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Hausen F. Relaxation Times of Ionic Liquids under Electrochemical Conditions Probed by Friction Force Microscopy. SMALL METHODS 2023; 7:e2300250. [PMID: 37551063 DOI: 10.1002/smtd.202300250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 07/14/2023] [Indexed: 08/09/2023]
Abstract
Ionic liquids (ILs) represent an important class of liquids considered for a broad range of applications such as lubrication, catalysis, or as electrolytes in batteries. It is well-known that in the case of charged surfaces, ILs form a pronounced layer structure that can be easily triggered by an externally applied electrode potential. Information about the time required to form a stable interface under varying electrode potentials is of utmost importance in many applications. For the first time, probing of relaxation times of ILs by friction force microscopy is demonstrated. The friction force is extremely sensitive to even subtle changes in the interfacial configuration of ILs. Various relaxation processes with different time scales are observed. A significant difference dependent on the direction of switching the applied potential, i.e., from a more cation-rich to a more anion-rich interface or vice versa, is found. Furthermore, variations in height immediately after the potential step and the presence of trace amounts of water are discussed as well.
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Affiliation(s)
- Florian Hausen
- Forschungszentrum Jülich, Institute of Energy and Climate Research, IEK-9, 52425, Jülich, Germany
- RWTH Aachen University, Institute of Physical Chemistry, 52074, Aachen, Germany
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany
- Jülich-Aachen Research Alliance, Section: JARA-Energy, 52425, Jülich, Germany
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3
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Freeman JS, Mamme MH, Ustarroz J, Warr GG, Li H, Atkin R. Molecular Resolution Nanostructure and Dynamics of the Deep Eutectic Solvent-Graphite Interface as a Function of Potential. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2204993. [PMID: 36627266 DOI: 10.1002/smll.202204993] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 12/08/2022] [Indexed: 06/17/2023]
Abstract
Interest in deep eutectic solvents (DESs), particularly for electrochemical applications, has boomed in the past decade because they are more versatile than conventional electrolyte solutions and are low cost, renewable, and non-toxic. The molecular scale lateral nanostructures as a function of potential at the solid-liquid interface-critical design parameters for the use of DESs as electrochemical solvents-are yet to be revealed. In this work, in situ amplitude modulated atomic force microscopy complemented by molecular dynamics simulations is used to probe the Stern and near-surface layers of the archetypal and by far most studied DES, 1:2 choline chloride:urea (reline), at the highly orientated pyrolytic graphite surface as a function of potential, to reveal highly ordered lateral nanostructures with unprecedented molecular resolution. This detail allows identification of choline, chloride, and urea in the Stern layer on graphite, and in some cases their orientations. Images obtained after the potential is switched from negative to positive show the dynamics of the Stern layer response, revealing that several minutes are required to reach equilibrium. These results provide valuable insight into the nanostructure and dynamics of DESs at the solid-liquid interface, with implications for the rational design of DESs for interfacial applications.
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Affiliation(s)
- Justin S Freeman
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Mesfin Haile Mamme
- Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel (VUB), Pleinlaan 2, Brussels, 1050, Belgium
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, Brussels, 1050, Belgium
| | - Jon Ustarroz
- Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel (VUB), Pleinlaan 2, Brussels, 1050, Belgium
- Chemistry of Surfaces, Interfaces and Nanomaterials (ChemSIN), Université Libre de Bruxelles, Boulevard du Triomphe 2, Brussels, 1050, Belgium
| | - Gregory G Warr
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Hua Li
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
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4
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Liu Z, Cheng J, Höfft O, Endres F. In situ XPS study of template-free electrodeposition of antimony nanowires from an ionic liquid. J Solid State Electrochem 2022. [DOI: 10.1007/s10008-022-05321-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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5
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Kobayashi T, Smiatek J, Fyta M. Probing the distribution of ionic liquid mixtures at charged and neutral interfaces via simulations and lattice-gas theory. Phys Chem Chem Phys 2022; 24:16471-16483. [PMID: 35766260 DOI: 10.1039/d2cp01346k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Room temperature ionic liquid solutions confined between neutral and charged surfaces are investigated by means of atomistic Molecular Dynamics simulations. We study 1-ethyl-3-methylimidazolium dicyanamide ([EMIm]+[DCA]-) in water or dimethylsulfoxide (DMSO) mixtures in confinement between two interfaces. The analysis is based on the comparison of the molecular species involved and the charged state of the surfaces. Focus is given on the influence of different water/DMSO concentrations on the microstructuring and accumulation of each species. Thermodynamic aspects, such as the entropic contributions in the observed trends are obtained from the simulations using a lattice-gas theory. The results clearly underline the differences in these properties for the water and DMSO mixtures and unravel the underlying mechanisms and inherent details. We were able to pinpoint the importance of the size and the relative permittivity of the molecules in guiding their microstructuring in the vicinity of the surfaces, as well as their interactions with the latter, i.e. the solute-surface interactions. The influence of water and DMSO on the overscreening at charged interfaces is also discussed. The analysis on the molecular accumulation at the interfaces allows us to predict whether the accumulation is entropy or enthalpy driven, which has an impact in the removal of the molecular species from the surfaces. We discuss the impact of this work in providing an essential understanding towards a careful design of electrochemical elements.
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Affiliation(s)
- Takeshi Kobayashi
- Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
| | - Jens Smiatek
- Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
| | - Maria Fyta
- Institute for Computational Physics, University of Stuttgart, Allmandring 3, 70569 Stuttgart, Germany.
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6
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Dong Y, Gong M, Shah FU, Laaksonen A, An R, Ji X. Phosphonium-Based Ionic Liquid Significantly Enhances SERS of Cytochrome c on TiO 2 Nanotube Arrays. ACS APPLIED MATERIALS & INTERFACES 2022; 14:27456-27465. [PMID: 35642388 PMCID: PMC9204693 DOI: 10.1021/acsami.2c05781] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/20/2022] [Indexed: 05/05/2023]
Abstract
Surface-enhanced Raman scattering (SERS) is an attractive technique for studying trace detection. It is of utmost importance to further improve the performance and understand the underlying mechanisms. An ionic liquid (IL), the anion of which is derived from biomass, [P6,6,6,14][FuA] was synthesized and used as a trace additive to improve the SERS performance of cytochrome c (Cyt c) on TiO2 nanotube arrays (TNAs). An increased and better enhancement factor (EF) by four to five times as compared to the system without an IL was obtained, which is better than that from using the choline-based amino acid IL previously reported by us. Dissociation of the ILs improved the ionic conductivity of the system, and the long hydrophobic tails of the [P6,6,6,14]+ cation contributed to a strong electrostatic interaction between Cyt c and the TNA surface, thereby enhancing the SERS performance. Atomic force microscopy did verify strong electrostatic interactions between the Cyt c molecules and TNAs after the addition of the IL. This work demonstrates the importance of introducing the phosphonium-based IL to enhance the SERS performance, which will stimulate further development of more effective ILs on SERS detection and other relevant applications in biology.
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Affiliation(s)
- Yihui Dong
- Department
of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mian Gong
- Herbert
Gleiter Institute of Nanoscience, Department of Materials Science
and Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
| | - Faiz Ullah Shah
- Chemistry
of Interfaces, Luleå University of
Technology, Luleå SE-971 87, Sweden
| | - Aatto Laaksonen
- Energy
Engineering, Division of Energy Science, Luleå University of Technology, Luleå 97187, Sweden
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm SE-10691, Sweden
- Center
of
Advanced Research in Bionanoconjugates and Biopolymers, ‘‘Petru Poni” Institute of Macromolecular
Chemistry, Iasi 700469, Romania
- State
Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Rong An
- Herbert
Gleiter Institute of Nanoscience, Department of Materials Science
and Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
| | - Xiaoyan Ji
- Energy
Engineering, Division of Energy Science, Luleå University of Technology, Luleå 97187, Sweden
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7
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Detailing molecular interactions of ionic liquids with charged SiO2 surfaces: A systematic AFM study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118506] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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8
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Seebeck J, Merlet C, Meißner RH. Elucidating Curvature-Capacitance Relationships in Carbon-Based Supercapacitors. PHYSICAL REVIEW LETTERS 2022; 128:086001. [PMID: 35275675 DOI: 10.1103/physrevlett.128.086001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Nanoscale surface curvatures, either convex or concave, strongly influence the charging behavior of supercapacitors. Rationalizing individual influences of electrode atoms to the capacitance is possible by interpreting distinct elements of the charge-charge covariance matrix derived from individual charge variations of the electrode atoms. An ionic liquid solvated in acetonitrile and confined between two electrodes, each consisting of three undulated graphene layers, serves as a demonstrator to illustrate pronounced and nontrivial features of the capacitance with respect to the electrode curvature. In addition, the applied voltage determines whether a convex or concave surface contributes to increased capacitance. While at lower voltages capacitance variations are in general correlated with ion number density variations in the double layer formed in the concave region of the electrode, for certain electrode designs a surprisingly strong contribution of the convex part to the differential capacitance is found both at higher and lower voltages.
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Affiliation(s)
- Jannes Seebeck
- Institute of Polymers and Composites, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Céline Merlet
- CIRIMAT, Université de Toulouse, CNRS, Université Toulouse 3 - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse cedex 9 - France and Réseau sur le Stockage Electrochimique de l'Energie (RS2E), Fédération de Recherche CNRS 3459, HUB de l'Energie, Rue Baudelocque, 80039 Amiens, France
| | - Robert H Meißner
- Institute of Polymers and Composites, Hamburg University of Technology, 21073 Hamburg, Germany and Helmholtz-Zentrum Hereon, Institute of Surface Science, 21502 Geesthacht, Germany
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9
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Montes-Campos H, Rivera-Pousa A, Méndez-Morales T. Density functional theory of alkali metals at the IL/graphene electrochemical interface. J Chem Phys 2022; 156:014706. [PMID: 34998333 DOI: 10.1063/5.0077449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The mechanism of charge transfer between metal ions and graphene in the presence of an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) is investigated by means of density functional theory calculations. For that purpose, two different comparisons are established: (i) the behavior of Li+ and K+ when adsorbed onto the basal plane of graphene and (ii) the differences between Li+ approaching the carbon surface from the basal plane and being intercalated through the edge plane of trilayer graphene. In the first case, it is found that the metal ions must overcome high energy barriers due to their interaction with the ionic liquid before reaching an equilibrium position close to the interface. In addition, no significant charge transfer between any of the metals and graphene takes place until very close energetically unfavorable distances. The second configuration shows that Li+ has no equilibrium position in the proximity of the interface but instead has an equilibrium position when it is inside the electrode for which it has to cross an energy barrier. In this case, the formation of a LiC12 complex is observed since the charge transfer at the equilibrium distance is achieved to a considerable extent. Thus, the interfacial charge transfer resistance on the electrode in energy devices based on ionic liquids clearly depends not only on the binding of the ionic liquid to the metal cations and their ability to form a dense solvation shell around them but also on the surface topography and its effect on the ion packing on the surface.
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Affiliation(s)
- H Montes-Campos
- Grupo de Nanomateriais, Fotónica e Materia Branda, Departamento de Física de Partículas, Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain
| | - A Rivera-Pousa
- Grupo de Nanomateriais, Fotónica e Materia Branda, Departamento de Física de Partículas, Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain
| | - T Méndez-Morales
- Grupo de Nanomateriais, Fotónica e Materia Branda, Departamento de Física de Partículas, Universidade de Santiago de Compostela, Campus Vida s/n, E-15782 Santiago de Compostela, Spain
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10
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Yan J, Mangolini F. Engineering encapsulated ionic liquids for next-generation applications. RSC Adv 2021; 11:36273-36288. [PMID: 35492767 PMCID: PMC9043619 DOI: 10.1039/d1ra05034f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/21/2021] [Indexed: 01/02/2023] Open
Abstract
Ionic liquids (ILs) have attracted considerable attention in several sectors (from energy storage to catalysis, from drug delivery to separation media) owing to their attractive properties, such as high thermal stability, wide electrochemical window, and high ionic conductivity. However, their high viscosity and surface tension compared to conventional organic solvents can lead to unfavorable transport properties. To circumvent undesired kinetics effects limiting mass transfer, the discretization of ILs into small droplets has been proposed as a method to increase the effective surface area and the rates of mass transfer. In the present review paper, we summarize the different methods developed so far for encapsulating ILs in organic or inorganic shells and highlight characteristic features of each approach, while outlining potential applications. The remarkable tunability of ILs, which derives from the high number of anions and cations currently available as well as their permutations, combines with the possibility of tailoring the composition, size, dispersity, and properties (e.g., mechanical, transport) of the shell to provide a toolbox for rationally designing encapsulated ILs for next-generation applications, including carbon capture, energy storage devices, waste handling, and microreactors. We conclude this review with an outlook on potential applications that could benefit from the possibility of encapsulating ILs in organic and inorganic shells. Encapsulated ionic liquids (ILs) are candidate materials for several applications owing to the attractive properties of ILs combined with the enhanced mass transfer rate obtained through the discretization of ILs in small capsules.![]()
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Affiliation(s)
- Jieming Yan
- Texas Materials Institute, The University of Texas at Austin Austin TX 78712 USA.,Materials Science and Engineering Program, The University of Texas at Austin Austin TX 78712 USA
| | - Filippo Mangolini
- Texas Materials Institute, The University of Texas at Austin Austin TX 78712 USA.,Walker Department of Mechanical Engineering, The University of Texas at Austin Austin TX 78712 USA
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11
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Meusel M, Gezmis A, Jaekel S, Lexow M, Bayer A, Maier F, Steinrück HP. Time- and Temperature-Dependent Growth Behavior of Ionic Liquids on Au(111) Studied by Atomic Force Microscopy in Ultrahigh Vacuum. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:20439-20449. [PMID: 34594432 PMCID: PMC8474146 DOI: 10.1021/acs.jpcc.1c06613] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Indexed: 06/13/2023]
Abstract
We deposited defined amounts of [C1C1Im][Tf2N] on Au(111) at different temperatures and investigated the morphology and wetting behavior of the deposited films by atomic force microscopy. For multilayer coverages, we observe a drastically different growth behavior when comparing deposition at room temperature (RT) and deposition below 170 K followed by slow annealing to RT. Upon deposition at RT, we find the formation of 2-30 nm high and 50-500 nm wide metastable 3D droplets on top of a checkerboard-type wetting layer. These droplets spread out into stable 2D bilayers, on the time scale of hours and days. The same 2D bilayer structure is obtained after deposition below 170 K and slow annealing to RT. We present a statistical analysis on the time-dependent changes of the shape and volume of the 3D droplets and the 2D bilayers. We attribute the stabilization of the 2D bilayers on the wetting layer and on already formed bilayers to the high degree of order in these layers. Notably, the transformation process from the 3D droplets to 2D bilayer islands is accelerated by tip effects and also X-ray radiation.
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12
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Gao Q, Tsai W, Balke N. In situ and operando force‐based atomic force microscopy for probing local functionality in energy storage materials. ELECTROCHEMICAL SCIENCE ADVANCES 2021. [DOI: 10.1002/elsa.202100038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Qiang Gao
- Department of Chemistry University of Wisconsin‐Madison Madison Wisconsin USA
| | - Wan‐Yu Tsai
- Chemical Science Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
| | - Nina Balke
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge Tennessee USA
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13
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Kobayashi T, Smiatek J, Fyta M. Energetic Arguments on the Microstructural Analysis in Ionic Liquids. ADVANCED THEORY AND SIMULATIONS 2021. [DOI: 10.1002/adts.202100114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Takeshi Kobayashi
- Institute for Computational Physics University of Stuttgart Allmandring 3 Stuttgart 70569 Germany
| | - Jens Smiatek
- Institute for Computational Physics University of Stuttgart Allmandring 3 Stuttgart 70569 Germany
| | - Maria Fyta
- Institute for Computational Physics University of Stuttgart Allmandring 3 Stuttgart 70569 Germany
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14
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Voroshylova IV, Ers H, Koverga V, Docampo-Álvarez B, Pikma P, Ivaništšev VB, Cordeiro M. Ionic liquid–metal interface: The origins of capacitance peaks. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138148] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Shen X, Sun T, Yang L, Krasnoslobodtsev A, Sabirianov R, Sealy M, Mei WN, Wu Z, Tan L. Ultra-fast charging in aluminum-ion batteries: electric double layers on active anode. Nat Commun 2021; 12:820. [PMID: 33547316 PMCID: PMC7864900 DOI: 10.1038/s41467-021-21108-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 01/07/2021] [Indexed: 11/08/2022] Open
Abstract
With the rapid iteration of portable electronics and electric vehicles, developing high-capacity batteries with ultra-fast charging capability has become a holy grail. Here we report rechargeable aluminum-ion batteries capable of reaching a high specific capacity of 200 mAh g-1. When liquid metal is further used to lower the energy barrier from the anode, fastest charging rate of 104 C (duration of 0.35 s to reach a full capacity) and 500% more specific capacity under high-rate conditions are achieved. Phase boundaries from the active anode are believed to encourage a high-flux charge transfer through the electric double layers. As a result, cationic layers inside the electric double layers responded with a swift change in molecular conformation, but anionic layers adopted a polymer-like configuration to facilitate the change in composition.
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Affiliation(s)
- Xuejing Shen
- School of Aerospace, Dalian University of Technology, Dalian, 116024, China
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, NE, 68588, USA
| | - Tao Sun
- School of Aerospace, Dalian University of Technology, Dalian, 116024, China
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, NE, 68588, USA
| | - Lei Yang
- School of Aerospace, Dalian University of Technology, Dalian, 116024, China
- Department of Physics, University of Nebraska, Omaha, NE, 68182, USA
| | - Alexey Krasnoslobodtsev
- Department of Physics, University of Nebraska, Omaha, NE, 68182, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - Renat Sabirianov
- Department of Physics, University of Nebraska, Omaha, NE, 68182, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - Michael Sealy
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, NE, 68588, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - Wai-Ning Mei
- Department of Physics, University of Nebraska, Omaha, NE, 68182, USA
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA
| | - Zhanjun Wu
- School of Aerospace, Dalian University of Technology, Dalian, 116024, China.
| | - Li Tan
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, NE, 68588, USA.
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA.
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16
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Voroshylova IV, Ers H, Docampo-Álvarez B, Pikma P, Ivaništšev VB, Cordeiro MNDS. Hysteresis in the MD Simulations of Differential Capacitance at the Ionic Liquid-Au Interface. J Phys Chem Lett 2020; 11:10408-10413. [PMID: 33253582 DOI: 10.1021/acs.jpclett.0c03212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this Letter, we report the first observation of the capacitance-potential hysteresis at the ionic liquid | electrode interface in atomistic molecular dynamics simulations. While modeling the differential capacitance dependence on the potential scan direction, we detected two long-living types of interfacial structure for the BMImPF6 ionic liquid at specific charge densities of the gold Au(111) surface. These structures differ in how counterions overscreen the surface charge. The high barrier for the transition from one structure to another slows down the interfacial restructuring process and leads to the marked capacitance-potential hysteresis.
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Affiliation(s)
- Iuliia V Voroshylova
- LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Heigo Ers
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia
| | | | - Piret Pikma
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia
| | | | - M Natália D S Cordeiro
- LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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17
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Meusel M, Lexow M, Gezmis A, Bayer A, Maier F, Steinrück HP. Growth of Multilayers of Ionic Liquids on Au(111) Investigated by Atomic Force Microscopy in Ultrahigh Vacuum. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13670-13681. [PMID: 33156635 PMCID: PMC7676296 DOI: 10.1021/acs.langmuir.0c02596] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Understanding the growth of ultrathin films of ionic liquids (ILs) on metal surfaces is of highest relevance for a variety of applications. We present a detailed study of the growth of the wetting layer and successive multilayers of 1,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C1C1Im][Tf2N]) on Au(111). By atomic force microscopy (AFM) in ultrahigh vacuum, we follow the temperature-dependent behavior between 110 and 300 K at defined coverages. We initially observe the formation of a wetting layer with a thickness of ∼0.37 nm with anions and cations arranged in a checkerboard structure. Stable AFM imaging up to 280 K allows us to follow the IL growing on top of the wetting layer in bilayers with an average thickness of ∼0.71 nm, that is, double the height of the wetting layer, in a bilayer-by-bilayer fashion. This growth behavior is independently confirmed from the surface morphology, as deduced from AFM and angle-resolved X-ray photoelectron spectroscopy. High-resolution AFM images at 110 K allow for identifying the molecular surface structure of the bilayers as a striped phase, which is one of the phases also seen for the wetting layer (Meusel, M.; Lexow, M.; Gezmis, A.; Schotz, S.; Wagner, M.; Bayer, A.; Maier, F.; Steinrück, H. P. Atomic Force and Scanning Tunneling Microscopy of Ordered Ionic Liquid Wetting Layers from 110 K up to Room Temperature. ACS Nano 2020, 14, 9000-9010).
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Affiliation(s)
- Manuel Meusel
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Matthias Lexow
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Afra Gezmis
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Andreas Bayer
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Florian Maier
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Hans-Peter Steinrück
- Lehrstuhl für Physikalische
Chemie II, Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
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18
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Hallett JE, Hayler HJ, Perkin S. Nanolubrication in deep eutectic solvents. Phys Chem Chem Phys 2020; 22:20253-20264. [PMID: 32966447 DOI: 10.1039/d0cp03787g] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report surface force balance measurements of the normal surface force and friction between two mica surfaces separated by a nanofilm of the deep eutectic solvent ethaline. Ethaline, a 1 : 2 mixture of choline chloride and ethylene glycol, was studied under dry conditions, under ambient conditions and with added water, revealing surface structural layers and quantised frictional response highly sensitive to water content, including regions of super-lubric behaviour under dry conditions and with added water. We also report exceptionally long-ranged electrostatic repulsion far in excess of that predicted by Debye-Hückel theory for a system with such high electrolyte content, consistent with previously reported observations of "underscreening" in ionic liquid and concentrated aqueous electrolyte systems [Smith et al., J. Phys. Chem. Lett., 2016, 7(12), 2157].
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Affiliation(s)
- James E Hallett
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK.
| | - Hannah J Hayler
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK.
| | - Susan Perkin
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK.
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19
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Meusel M, Lexow M, Gezmis A, Schötz S, Wagner M, Bayer A, Maier F, Steinrück HP. Atomic Force and Scanning Tunneling Microscopy of Ordered Ionic Liquid Wetting Layers from 110 K up to Room Temperature. ACS NANO 2020; 14:9000-9010. [PMID: 32609482 PMCID: PMC7391993 DOI: 10.1021/acsnano.0c03841] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/01/2020] [Indexed: 05/31/2023]
Abstract
Ionic liquids (ILs) are used as ultrathin films in many applications. We studied the nanoscale arrangement within the first layer of 1,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C1C1Im] [Tf2N]) on Au(111) between 400 and 110 K in ultrahigh vacuum by scanning tunneling and noncontact atomic force microscopy with molecular resolution. Compared to earlier studies on similar ILs, a different behavior is observed, which we attribute to the small size and symmetrical shape of the cation: (a) In both AFM and STM only the anions are imaged; (b) only long-range-ordered but no amorphous phases are observed; (c) the hexagonal room-temperature phase melts 30-50 K above the IL's bulk melting point; (d) at 110 K, striped and hexagonal superstructures with two and three ion pairs per unit cell, respectively, are found. AFM turned out to be more stable at higher temperature, while STM revealed more details at low temperature.
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Affiliation(s)
- Manuel Meusel
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Matthias Lexow
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Afra Gezmis
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Simon Schötz
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Margareta Wagner
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/134, 1040 Vienna, Austria
| | - Andreas Bayer
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Florian Maier
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
| | - Hans-Peter Steinrück
- Lehrstuhl
für Physikalische Chemie II, Universität
Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
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20
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Wang YL, Li B, Sarman S, Mocci F, Lu ZY, Yuan J, Laaksonen A, Fayer MD. Microstructural and Dynamical Heterogeneities in Ionic Liquids. Chem Rev 2020; 120:5798-5877. [PMID: 32292036 PMCID: PMC7349628 DOI: 10.1021/acs.chemrev.9b00693] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Ionic liquids (ILs) are a special category of molten salts solely composed of ions with varied molecular symmetry and charge delocalization. The versatility in combining varied cation-anion moieties and in functionalizing ions with different atoms and molecular groups contributes to their peculiar interactions ranging from weak isotropic associations to strong, specific, and anisotropic forces. A delicate interplay among intra- and intermolecular interactions facilitates the formation of heterogeneous microstructures and liquid morphologies, which further contributes to their striking dynamical properties. Microstructural and dynamical heterogeneities of ILs lead to their multifaceted properties described by an inherent designer feature, which makes ILs important candidates for novel solvents, electrolytes, and functional materials in academia and industrial applications. Due to a massive number of combinations of ion pairs with ion species having distinct molecular structures and IL mixtures containing varied molecular solvents, a comprehensive understanding of their hierarchical structural and dynamical quantities is of great significance for a rational selection of ILs with appropriate properties and thereafter advancing their macroscopic functionalities in applications. In this review, we comprehensively trace recent advances in understanding delicate interplay of strong and weak interactions that underpin their complex phase behaviors with a particular emphasis on understanding heterogeneous microstructures and dynamics of ILs in bulk liquids, in mixtures with cosolvents, and in interfacial regions.
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Affiliation(s)
- Yong-Lei Wang
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Bin Li
- School
of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China
| | - Sten Sarman
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Francesca Mocci
- Department
of Chemical and Geological Sciences, University
of Cagliari, I-09042 Monserrato, Italy
| | - Zhong-Yuan Lu
- State
Key Laboratory of Supramolecular Structure and Materials, Institute
of Theoretical Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Jiayin Yuan
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
- State
Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 210009, P. R. China
- Centre of
Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, 41A, 700487 Iasi, Romania
- Department
of Engineering Sciences and Mathematics, Division of Energy Science, Luleå University of Technology, SE-97187 Luleå, Sweden
| | - Michael D. Fayer
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
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21
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Li H, Niemann T, Ludwig R, Atkin R. Effect of Hydrogen Bonding between Ions of Like Charge on the Boundary Layer Friction of Hydroxy-Functionalized Ionic Liquids. J Phys Chem Lett 2020; 11:3905-3910. [PMID: 32338913 DOI: 10.1021/acs.jpclett.0c00689] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Atomic force microscopy has been used to measure the lubricity of a series of ionic liquids (ILs) at mica surfaces in the boundary friction regime. A previously unreported cation bilayer structure is detected at the IL-mica interface due to the formation of H-bonds between the hydroxy-functionalized cations [(c-c) H-bonds], which enhances the ordering of the ions in the boundary layer and improves the lubrication. The strength of the cation bilayer structure is controlled by altering the strength of (c-c) H-bonding via changes in the hydroxyalkyl chain length, the cation charge polarizability, and the coordination strength of the anions. This reveals a new means of controlling IL boundary nanostructure via H-bonding between ions of the same charge, which can impact diverse applications, including surface catalysis, particle stability, electrochemistry, etc.
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Affiliation(s)
- Hua Li
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Thomas Niemann
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany
- Department LL&M, University of Rostock, Albert-Einstein-Strasse 25, 18059 Rostock, Germany
| | - Ralf Ludwig
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany
- Department LL&M, University of Rostock, Albert-Einstein-Strasse 25, 18059 Rostock, Germany
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, Western Australia 6009, Australia
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22
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Wu B, Breen JP, Xing X, Fayer MD. Controlling the Dynamics of Ionic Liquid Thin Films via Multilayer Surface Functionalization. J Am Chem Soc 2020; 142:9482-9492. [PMID: 32349470 DOI: 10.1021/jacs.0c03044] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The structural dynamics of planar thin films of an ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BmimNTf2) as a function of surface charge density and thickness were investigated using two-dimensional infrared (2D IR) spectroscopy. The films were made by spin coating a methanol solution of the IL on silica substrates that were functionalized with alkyl chains containing head groups that mimic the IL cation. The thicknesses of the ionic liquid films ranged from ∼50 to ∼250 nm. The dynamics of the films are slower than those in the bulk IL, becoming increasingly slow as the films become thinner. Control of the dynamics of the IL films can be achieved by adjusting the charge density on substrates through multilayer network surface functionalization. The charge density of the surface (number of positively charged groups in the network bound to the surface per unit area) is controlled by the duration of the functionalization reaction. As the charge density is increased, the IL dynamics become slower. For comparison, the surface was functionalized with three different neutral groups. Dynamics of the IL films on the functionalized neutral surfaces are faster than on any of the ionic surfaces but still slower than the bulk IL, even for the thickest films. These results can have implications in applications that employ ILs that have electrodes, such as batteries, as the electrode surface charge density will influence properties like diffusion close to the surface.
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Affiliation(s)
- Boning Wu
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - John P Breen
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Xiangyu Xing
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Michael D Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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23
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Funari R, Matsumoto A, de Bruyn JR, Shen AQ. Rheology of the Electric Double Layer in Electrolyte Solutions. Anal Chem 2020; 92:8244-8253. [DOI: 10.1021/acs.analchem.0c00475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Riccardo Funari
- Micro/Bio/Nanofluidics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Atsushi Matsumoto
- Micro/Bio/Nanofluidics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - John R. de Bruyn
- Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Amy Q. Shen
- Micro/Bio/Nanofluidics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
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24
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Katakura S, Nishi N, Kobayashi K, Amano KI, Sakka T. An electric double layer structure and differential capacitance at the electrode interface of tributylmethylammonium bis(trifluoromethanesulfonyl)amide studied using a molecular dynamics simulation. Phys Chem Chem Phys 2020; 22:5198-5210. [PMID: 32090216 DOI: 10.1039/c9cp05297f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A molecular dynamics simulation at the electrode interface of a quaternary ammonium ionic liquid, tributylmethylammonium bis(trifluoromethanesulfonyl)amide ([N1444+][TFSA-]), has been performed. Unlike the commonly used cations, such as 1-alkyl-3-methylimidazolium and 1,1-alkylmethylpyrrolidinium cations, N1444+ has multiple long-alkyl groups (three butyl groups). The behavior of ions at the electrode interface, especially these butyl groups, has been investigated. N1444+ at the first layer mainly has two types of orientations, lying and standing. The lying orientation is dominant at moderately negative potentials. However, the standing one becomes dominant at the more negative potentials. Due to this orientational change, the number of N1444+ increases at the first layer as the potential becomes negative even at the potentials where the anions are completely depleted there. The change in orientation results in the upward deviation of the differential capacitance from the theoretical prediction at the negative potentials. The results suggest that the orientational preference caused by the steric constraint between alkyl groups plays an important role in the behavior of the electric double layer of the ionic liquids.
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Affiliation(s)
- Seiji Katakura
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
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25
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Greco F, Shin S, Williams FJ, Heller BSJ, Maier F, Steinrück H. Potential Screening at Electrode/Ionic Liquid Interfaces from In Situ X-ray Photoelectron Spectroscopy. ChemistryOpen 2019; 8:1365-1368. [PMID: 31844602 PMCID: PMC6892450 DOI: 10.1002/open.201900211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Indexed: 11/12/2022] Open
Abstract
A new approach to investigate potential screening at the interface of ionic liquids (ILs) and charged electrodes in a two-electrode electrochemical cell by in situ X-ray photoelectron spectroscopy has been introduced. Using identical electrodes, we deduce the potential screening at the working and the counter electrodes as a function of applied voltage from the potential change of the bulk IL, as derived from corresponding core level binding energy shifts for different IL/electrode combinations. For imidazolium-based ILs and Pt electrodes, we find a significantly larger potential screening at the anode than at the cathode, which we attribute to strong attractive interactions between the imidazolium cation and Pt. In the absence of specific ion/electrode interactions, asymmetric potential screening only occurs for ILs with different cation and anion sizes as demonstrated for an imidazolium chloride IL and Au electrodes, which we assign to the different thicknesses of the electrical double layers. Our results imply that potential screening in ILs is mainly established by a single layer of counterions at the electrode.
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Affiliation(s)
- Francesco Greco
- Lehrstuhl für Physikalische Chemie 2Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Sunghwan Shin
- Lehrstuhl für Physikalische Chemie 2Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Federico J. Williams
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE-CONICETUniversidad de Buenos Aires, Ciudad UniversitariaPabellón 2Buenos AiresC1428EHAArgentina
| | - Bettina S. J. Heller
- Lehrstuhl für Physikalische Chemie 2Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Florian Maier
- Lehrstuhl für Physikalische Chemie 2Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
| | - Hans‐Peter Steinrück
- Lehrstuhl für Physikalische Chemie 2Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstr. 391058ErlangenGermany
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26
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Sun C, Zhao W, Zhang H, Feng G. Molecular insight into structures of monocationic and dicationic ionic liquids in mica slits. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1678773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Chen Sun
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China
| | - Wei Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China
| | - Huanhuan Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China
| | - Guang Feng
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China
- Nano Interface Centre for Energy, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China
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27
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Häckl K, Li H, Aldous IM, Tsui T, Kunz W, Abbott AP, Warr GG, Atkin R. Potential Dependence of Surfactant Adsorption at the Graphite Electrode/Deep Eutectic Solvent Interface. J Phys Chem Lett 2019; 10:5331-5337. [PMID: 31430167 DOI: 10.1021/acs.jpclett.9b01968] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Atomic force microscopy and cyclic voltammetry are used to probe how ionic surfactant adsorbed layer structure affects redox processes at deep eutectic solvent (DES)/graphite interfaces. Unlike its behavior in water, sodium dodecyl sulfate (SDS) in DESs only adsorbs as a complete layer of hemicylindrical hemimicelles far above its critical micelle concentration (CMC). Near the CMC it forms a tail-to-tail monolayer at open-circuit potential (OCP) and positive potentials, and it desorbs at negative potentials. In contrast, cetyltrimethylammonium bromide (CTAB) adsorbs as hemimicelles at low concentrations and remains adsorbed at both positive and negative potentials. The SDS horizontal monolayer has little overall effect on redox processes at the graphite interface, but hemimicelles form an effective and stable barrier. The stronger solvophobic interactions between the C16 versus C12 alkyl chains in the DES allow CTAB to self-assemble into a robust coating at low concentrations and illustrate how the structure of the DES/electrode interface and electrochemical response can be engineered by controlling surfactant structure.
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Affiliation(s)
- Katharina Häckl
- Institute of Physical and Theoretical Chemistry , University of Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
- School of Molecular Sciences , The University of Western Australia , 35 Stirling Highway , Perth , WA 6009 , Australia
| | - Hua Li
- School of Molecular Sciences , The University of Western Australia , 35 Stirling Highway , Perth , WA 6009 , Australia
- Centre for Microscopy, Characterisation and Analysis , The University of Western Australia , 35 Stirling Highway , Perth , WA 6009 , Australia
| | - Iain M Aldous
- Materials Centre, Department of Chemistry , University of Leicester , Leicester LE1 7RH , U.K
| | - Terrence Tsui
- School of Molecular Sciences , The University of Western Australia , 35 Stirling Highway , Perth , WA 6009 , Australia
| | - Werner Kunz
- Institute of Physical and Theoretical Chemistry , University of Regensburg , Universitätsstraße 31 , D-93053 Regensburg , Germany
| | - Andrew P Abbott
- Materials Centre, Department of Chemistry , University of Leicester , Leicester LE1 7RH , U.K
| | - Gregory G Warr
- School of Chemistry and University of Sydney Nano Institute , The University of Sydney , Camperdown , NSW 2006 , Australia
| | - Rob Atkin
- School of Molecular Sciences , The University of Western Australia , 35 Stirling Highway , Perth , WA 6009 , Australia
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28
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Abstract
Ionic liquids have become of significant relevance in chemistry, as they can serve as environmentally-friendly solvents, electrolytes, and lubricants with bespoke properties. In particular for electrochemical applications, an understanding of the interface structure between the ionic liquid and an electrified interface is needed to model and optimize the reactions taking place on the solid surface. As with ionic liquids, the interplay between electrostatic forces and steric effects leads to an intrinsic heterogeneity, as the structure of the ionic liquid above an electrified interface cannot be described by the classical electrical double layer model. Instead, a layered solvation layer is present with a structure that depends on the material combination of the ionic liquid and substrate. In order to experimentally monitor this structure, atomic force spectroscopy (AFS) has become the method of choice. By measuring the force acting on a sharp microfabricated tip while approaching the surface in an ionic liquid, it has become possible to map the solvation layers with sub-nanometer resolution. In this review, we provide an overview of the AFS studies on ionic liquids published in recent years that illustrate how the interface is formed and how it can be modified by applying electrical potential or by adding impurities and solvents.
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29
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Xia H, Hua X, Long YT. Visualization of the Electrolyte Migration under Electrochemical Process by ToF-SIMS. ACTA CHIMICA SINICA 2019. [DOI: 10.6023/a19070281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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30
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Panhwar GM, Mysyk R, Rojo T, Shaikhutdinov S, Bondarchuk O. Electrowetting of Ionic Liquid on Graphite: Probing via in Situ Electrochemical X-ray Photoelectron Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:14528-14536. [PMID: 30412414 DOI: 10.1021/acs.langmuir.8b02900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Thin films of ionic liquid 1-ethyl-3-methylimidazolium bis(fluoromethylsulfonyl)imide ([EMIm][FSI]) vapor-deposited on highly oriented pyrographite (HOPG) were studied by X-ray photoelectron spectroscopy and atomic force microscopy. The results revealed a reversible morphological transition from a "drop-on-layer" structure to a "flat-layer" structure at positive, and not at negative, polarization. The effect is rationalized in terms of electric-field-induced reduction of the liquid-solid transition temperature in the ionic liquid film, when its thickness is comparable to the charge screening length. The observed bias asymmetry of [EMIm][FSI] electrowetting on HOPG is tentatively explained by the bilayer structure at the interface driven by the affinity of the imidazolium ring to the HOPG surface.
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Affiliation(s)
- Ghulam M Panhwar
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Roman Mysyk
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Teófilo Rojo
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
| | - Shamil Shaikhutdinov
- Abteilung Chemische Physik , Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , 14195 Berlin , Germany
| | - Oleksandr Bondarchuk
- CIC Energigune , Parque Tecnológico de Alava , c/A. Einstein 48 , 01510 Miñano , Alava , Spain
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31
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Chen M, Goodwin ZA, Feng G, Kornyshev AA. On the temperature dependence of the double layer capacitance of ionic liquids. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.11.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Kislenko SA, Moroz YO, Karu K, Ivaništšev VB, Fedorov MV. Calculating the Maximum Density of the Surface Packing of Ions in Ionic Liquids. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2018. [DOI: 10.1134/s0036024418050187] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Lucio AJ, Shaw SK. Capacitive hysteresis at the 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)-trifluorophosphate-polycrystalline gold interface. Anal Bioanal Chem 2018; 410:4575-4586. [PMID: 29492622 DOI: 10.1007/s00216-018-0962-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 11/24/2022]
Abstract
We report potential-dependent capacitance curves over a 2-V potential range for the 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)-trifluorophosphate (Emim FAP)-polycrystalline gold interface, and examine the effect of potential scan direction on results. We find very small levels of capacitive hysteresis in the Emim FAP-polycrystalline Au electrochemical system, where capacitance curves show minor dependence on the potential scan direction employed. This is a considerably different response than that reported for the Emim FAP-Au(111) interface where significant hysteresis is observed based on the potential scan direction (Drüschler et al. in J Phys Chem C 115 (14):6802-6808, 2011). Hysteresis effects have previously been suggested to be a general feature of an ionic liquid (IL) at electrified interfaces due to slow interfacial processes and has been demonstrated for numerous electrochemical systems. We provide new evidence that the experimental procedure used to acquire capacitance data and data workup could also have implications on capacitance-potential relationships in ILs. This work serves to progress our understanding of the nature of capacitive hysteresis at the IL-electrode interface. Graphical abstract Subtle changes in experimental methods can lead to significantly different capacitance measurements in ionic liquids. Which is the best approach?
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Affiliation(s)
- Anthony J Lucio
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA
| | - Scott K Shaw
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA.
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Kiani S, Taherkhani F. Free energy, configurational and nonextensivity of Tsallis entropy with the size and temperature in colloidal silver nanoparticles in [EMim][PF6] ionic liquid. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.11.139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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35
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Reichert P, Kjær KS, Brandt van Driel T, Mars J, Ochsmann JW, Pontoni D, Deutsch M, Nielsen MM, Mezger M. Molecular scale structure and dynamics at an ionic liquid/electrode interface. Faraday Discuss 2018; 206:141-157. [DOI: 10.1039/c7fd00171a] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural arrangement and dynamics of ions near the IL/electrode interface during charging and discharging was studied by a combination of time resolved X-ray reflectivity and impedance spectroscopy.
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Affiliation(s)
- Peter Reichert
- Max Planck Institute for Polymer Research
- 55128 Mainz
- Germany
- Institute of Physics and MAINZ Graduate School
- Johannes Gutenberg University Mainz
| | - Kasper Skov Kjær
- Centre for Molecular Movies
- Department of Physics
- Technical University of Denmark
- DK-2800 Lyngby
- Denmark
| | - Tim Brandt van Driel
- Centre for Molecular Movies
- Department of Physics
- Technical University of Denmark
- DK-2800 Lyngby
- Denmark
| | - Julian Mars
- Max Planck Institute for Polymer Research
- 55128 Mainz
- Germany
- Institute of Physics and MAINZ Graduate School
- Johannes Gutenberg University Mainz
| | | | - Diego Pontoni
- ESRF – The European Synchrotron and Partnership for Soft Condensed Matter (PSCM)
- 38043 Grenoble
- France
| | - Moshe Deutsch
- Department of Physics
- Institute of Nanotechnology and Advanced Materials
- Bar-Ilan University
- Ramat-Gan 52900
- Israel
| | - Martin Meedom Nielsen
- Centre for Molecular Movies
- Department of Physics
- Technical University of Denmark
- DK-2800 Lyngby
- Denmark
| | - Markus Mezger
- Max Planck Institute for Polymer Research
- 55128 Mainz
- Germany
- Institute of Physics and MAINZ Graduate School
- Johannes Gutenberg University Mainz
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36
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Hoffmann V, Pulletikurthi G, Carstens T, Lahiri A, Borodin A, Schammer M, Horstmann B, Latz A, Endres F. Influence of a silver salt on the nanostructure of a Au(111)/ionic liquid interface: an atomic force microscopy study and theoretical concepts. Phys Chem Chem Phys 2018; 20:4760-4771. [DOI: 10.1039/c7cp08243f] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We combine in situ atomic force microscopy and non-equilibrium thermodynamics to investigate the Au(111)/electrolyte interface. Experiment and theory show that the concentration of solutes strongly influences the structure of the electrode/electrolyte interface.
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Affiliation(s)
- Viktor Hoffmann
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Giridhar Pulletikurthi
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Timo Carstens
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Abhishek Lahiri
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Andriy Borodin
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Max Schammer
- Helmholtz Institute Ulm
- 89081 Ulm
- Germany
- German Aerospace Center
- 70569 Stuttgart
| | - Birger Horstmann
- Helmholtz Institute Ulm
- 89081 Ulm
- Germany
- German Aerospace Center
- 70569 Stuttgart
| | - Arnulf Latz
- Helmholtz Institute Ulm
- 89081 Ulm
- Germany
- German Aerospace Center
- 70569 Stuttgart
| | - Frank Endres
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
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37
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Garcia L, Jacquot L, Charlaix E, Cross B. Nano-mechanics of ionic liquids at dielectric and metallic interfaces. Faraday Discuss 2018; 206:443-457. [DOI: 10.1039/c7fd00149e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using a dynamic surface force apparatus, we investigate the nano-mechanics and the nano-rheology of an ionic liquid at dielectric and metallic solid surfaces.
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Affiliation(s)
- Léo Garcia
- Université Grenoble Alpes
- CNRS
- LIPhy
- Grenoble
- France
| | - Léa Jacquot
- Université Grenoble Alpes
- CNRS
- LIPhy
- Grenoble
- France
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38
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Borisenko N, Lahiri A, Pulletikurthi G, Cui T, Carstens T, Zahlbach J, Atkin R, Endres F. The Au(111)/IL interfacial nanostructure in the presence of precursors and its influence on the electrodeposition process. Faraday Discuss 2018; 206:459-473. [DOI: 10.1039/c7fd00165g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ionic liquids have attracted significant interest as electrolytes for the electrodeposition of metals and semiconductors, but the details of the deposition processes are not yet well understood.
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Affiliation(s)
- Natalia Borisenko
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Abhishek Lahiri
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Giridhar Pulletikurthi
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Tong Cui
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Timo Carstens
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Janine Zahlbach
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
| | - Rob Atkin
- School of Molecular Sciences
- The University of Western Australia
- Australia
| | - Frank Endres
- Institute of Electrochemistry
- Clausthal University of Technology
- 38678 Clausthal-Zellerfeld
- Germany
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39
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Lucio AJ, Shaw SK. Effects and controls of capacitive hysteresis in ionic liquid electrochemical measurements. Analyst 2018; 143:4887-4900. [DOI: 10.1039/c8an01085d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Capacitance vs. potential relationships help electrochemists better understand electrode–liquid interfacial behaviors.
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Affiliation(s)
| | - Scott K. Shaw
- Department of Chemistry
- University of Iowa
- Iowa City
- USA
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40
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Black JM, Come J, Bi S, Zhu M, Zhao W, Wong AT, Noh JH, Pudasaini PR, Zhang P, Okatan MB, Dai S, Kalinin SV, Rack PD, Ward TZ, Feng G, Balke N. Role of Electrical Double Layer Structure in Ionic Liquid Gated Devices. ACS APPLIED MATERIALS & INTERFACES 2017; 9:40949-40958. [PMID: 29063758 DOI: 10.1021/acsami.7b11044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ionic liquid gating of transition metal oxides has enabled new states (magnetic, electronic, metal-insulator), providing fundamental insights into the physics of strongly correlated oxides. However, despite much research activity, little is known about the correlation of the structure of the liquids in contact with the transition metal oxide surface, its evolution with the applied electric potential, and its correlation with the measured electronic properties of the oxide. Here, we investigate the structure of an ionic liquid at a semiconducting oxide interface during the operation of a thin film transistor where the electrical double layer gates the device using experiment and theory. We show that the transition between the ON and OFF states of the amorphous indium gallium zinc oxide transistor is accompanied by a densification and preferential spatial orientation of counterions at the oxide channel surface. This process occurs in three distinct steps, corresponding to ion orientations, and consequently, regimes of different electrical conductivity. The reason for this can be found in the surface charge densities on the oxide surface when different ion arrangements are present. Overall, the field-effect gating process is elucidated in terms of the interfacial ionic liquid structure, and this provides unprecedented insight into the working of a liquid gated transistor linking the nanoscopic structure to the functional properties. This knowledge will enable both new ionic liquid design as well as advanced device concepts.
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Affiliation(s)
| | | | - Sheng Bi
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | - Mengyang Zhu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | - Wei Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
| | | | | | | | | | | | | | | | | | | | - Guang Feng
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology (HUST) , Wuhan 430074, China
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41
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Liu Z, Cui T, Li G, Endres F. Interfacial Nanostructure and Asymmetric Electrowetting of Ionic Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9539-9547. [PMID: 28248522 DOI: 10.1021/acs.langmuir.7b00082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this work, the interfacial nanostructure and electrowetting of ionic liquids having the same 1-ethyl-3-methylimidazolium cation ([EMIm]+) but different anions such as bis(trifluoromethylsulfonyl)imide (TFSI-), trifluoromethylsulfonate (TfO-), methylsulfonate (OMs-), acetate (OAc-), bis(fluorosulfonyl)imide (FSI-), dicyanamide (DCA-), and tris(pentafluorethyl)trifluorphosphat (FAP-) on bare metallic electrodes were investigated. In the investigated voltammetric potential regime, the contact angle versus voltage curve is asymmetric with respect to surface polarity. The electrowetting of the ILs occurs at negative potentials but does not occur at positive potentials. In situ atomic force microscopy (AFM) shows that the IL adopts a multilayered structure at the solid/IL interface, and a cation-rich layer is present in the innermost layer during cathodic polarization. The cations can change their orientation and propagate ahead of the three-phase contact line by diffusion, leading to further spreading on the negatively charged surface. The formation of such a surface layer is also evidenced by X-ray photoelectron spectroscopy. Such a surface diffusion mechanism does not occur during anodic polarization, where anions are enriched. In addition, the influence of substrate, water, and dissolved zinc salts on the electrowetting of ILs was studied. Our findings provide valuable insights for the interfacial nanostructure and the electrowetting of ILs.
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Affiliation(s)
- Zhen Liu
- Institute of Electrochemistry, Clausthal University of Technology , Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld, Germany
| | - Tong Cui
- Institute of Electrochemistry, Clausthal University of Technology , Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld, Germany
| | - GuoZhu Li
- Institute of Electrochemistry, Clausthal University of Technology , Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld, Germany
| | - Frank Endres
- Institute of Electrochemistry, Clausthal University of Technology , Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld, Germany
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42
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43
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Comtet J, Niguès A, Kaiser V, Coasne B, Bocquet L, Siria A. Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening. NATURE MATERIALS 2017; 16:634-639. [PMID: 28346432 PMCID: PMC5446787 DOI: 10.1038/nmat4880] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/14/2017] [Indexed: 05/31/2023]
Abstract
Room-temperature ionic liquids (RTILs) are new materials with fundamental importance for energy storage and active lubrication. They are unusual liquids, which challenge the classical frameworks of electrolytes, whose behaviour at electrified interfaces remains elusive, with exotic responses relevant to their electrochemical activity. Using tuning-fork-based atomic force microscope nanorheological measurements, we explore here the properties of confined RTILs, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This behaviour is interpreted in terms of the shift of the freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures, and suggests applications to tune nanoscale lubrication with phase-changing RTILs, by varying the nature and patterning of the substrate, and application of active polarization.
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Affiliation(s)
- Jean Comtet
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Antoine Niguès
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Vojtech Kaiser
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Benoit Coasne
- Laboratoire Interdisciplinaire de Physique, CNRS and Université Grenoble Alpes, UMR CNRS 5588, 38000 Grenoble, France
| | - Lydéric Bocquet
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
| | - Alessandro Siria
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, UMR CNRS 8550, PSL Research University, 75005 Paris Cedex 05, France
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44
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Li H, Rutland MW, Watanabe M, Atkin R. Boundary layer friction of solvate ionic liquids as a function of potential. Faraday Discuss 2017; 199:311-322. [PMID: 28422196 DOI: 10.1039/c6fd00236f] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Atomic force microscopy (AFM) has been used to investigate the potential dependent boundary layer friction at solvate ionic liquid (SIL)-highly ordered pyrolytic graphite (HOPG) and SIL-Au(111) interfaces. Friction trace and retrace loops of lithium tetraglyme bis(trifluoromethylsulfonyl)amide (Li(G4) TFSI) at HOPG present clearer stick-slip events at negative potentials than at positive potentials, indicating that a Li+ cation layer adsorbed to the HOPG lattice at negative potentials which enhances stick-slip events. The boundary layer friction data for Li(G4) TFSI shows that at HOPG, friction forces at all potentials are low. The TFSI- anion rich boundary layer at positive potentials is more lubricating than the Li+ cation rich boundary layer at negative potentials. These results suggest that boundary layers at all potentials are smooth and energy is predominantly dissipated via stick-slip events. In contrast, friction at Au(111) for Li(G4) TFSI is significantly higher at positive potentials than at negative potentials, which is comparable to that at HOPG at the same potential. The similarity of boundary layer friction at negatively charged HOPG and Au(111) surfaces indicates that the boundary layer compositions are similar and rich in Li+ cations for both surfaces at negative potentials. However, at Au(111), the TFSI- rich boundary layer is less lubricating than the Li+ rich boundary layer, which implies that anion reorientations rather than stick-slip events are the predominant energy dissipation pathways. This is confirmed by the boundary friction of Li(G4) NO3 at Au(111), which shows similar friction to Li(G4) TFSI at negative potentials due to the same cation rich boundary layer composition, but even higher friction at positive potentials, due to higher energy dissipation in the NO3- rich boundary layer.
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Affiliation(s)
- Hua Li
- Priority Research Centre for Advanced Fluids and Interfaces, The University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Mark W Rutland
- School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE100 44 Sweden and Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, SE114 86 Sweden
| | - Masayoshi Watanabe
- Department of Chemistry and Biotechnology, Yokohama National University, Yokohama 240-8501, Japan
| | - Rob Atkin
- Priority Research Centre for Advanced Fluids and Interfaces, The University of Newcastle, Callaghan, NSW 2308, Australia.
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45
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Biedron AB, Garfunkel EL, Castner EW, Rangan S. Ionic liquid ultrathin films at the surface of Cu(100) and Au(111). J Chem Phys 2017; 146:054704. [DOI: 10.1063/1.4975101] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Aleksandra B. Biedron
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Eric L. Garfunkel
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Edward W. Castner
- Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA
| | - Sylvie Rangan
- Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA
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46
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Pulletikurthi G, Shapouri Ghazvini M, Cui T, Borisenko N, Carstens T, Borodin A, Endres F. Electrodeposition of zinc nanoplates from an ionic liquid composed of 1-butylpyrrolidine and ZnCl2: electrochemical, in situ AFM and spectroscopic studies. Dalton Trans 2017; 46:455-464. [PMID: 27957582 DOI: 10.1039/c6dt04149c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Electrodeposition of Zn nanoplates from an ionic liquid composed of cationic and anionic zinc-chloro complexes as constituent ions.
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Affiliation(s)
- Giridhar Pulletikurthi
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
| | | | - Tong Cui
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
| | - Natalia Borisenko
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
| | - Timo Carstens
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
| | - Andriy Borodin
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
| | - Frank Endres
- Institute of Electrochemistry
- Clausthal University of Technology
- Clausthal-Zellerfeld
- Germany
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47
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Begić S, Jónsson E, Chen F, Forsyth M. Molecular dynamics simulations of pyrrolidinium and imidazolium ionic liquids at graphene interfaces. Phys Chem Chem Phys 2017; 19:30010-30020. [DOI: 10.1039/c7cp03389c] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
MD simulations of ionic liquids support AFM data and point towards a likely relationship between interfacial structures and electrochemical performance.
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Affiliation(s)
- Srđan Begić
- ARC Centre of Excellence for Electromaterials Science and Institute for Frontier Materials (IFM)
- Burwood
- Australia
| | - Erlendur Jónsson
- ARC Centre of Excellence for Electromaterials Science and Institute for Frontier Materials (IFM)
- Burwood
- Australia
| | - Fangfang Chen
- ARC Centre of Excellence for Electromaterials Science and Institute for Frontier Materials (IFM)
- Burwood
- Australia
| | - Maria Forsyth
- ARC Centre of Excellence for Electromaterials Science and Institute for Frontier Materials (IFM)
- Burwood
- Australia
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48
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Goodwin ZA, Feng G, Kornyshev AA. Mean-Field Theory of Electrical Double Layer In Ionic Liquids with Account of Short-Range Correlations. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.092] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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49
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Affiliation(s)
- Kun Liu
- Department of Chemical and Environmental Engineering, University of California , Riverside, CA, USA
| | - Cheng Lian
- Department of Chemical and Environmental Engineering, University of California , Riverside, CA, USA
- State Key Laboratory of Chemical Engineering, East China University of Science and Technology , Shanghai, P.R.China
| | - Douglas Henderson
- Department of Chemistry and Biochemistry, Brigham Young University , Provo, UT, USA
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California , Riverside, CA, USA
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50
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Feist A, Bach N, Rubiano da Silva N, Danz T, Möller M, Priebe KE, Domröse T, Gatzmann JG, Rost S, Schauss J, Strauch S, Bormann R, Sivis M, Schäfer S, Ropers C. Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam. Ultramicroscopy 2016; 176:63-73. [PMID: 28139341 DOI: 10.1016/j.ultramic.2016.12.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/30/2016] [Accepted: 12/02/2016] [Indexed: 10/20/2022]
Abstract
We present the development of the first ultrafast transmission electron microscope (UTEM) driven by localized photoemission from a field emitter cathode. We describe the implementation of the instrument, the photoemitter concept and the quantitative electron beam parameters achieved. Establishing a new source for ultrafast TEM, the Göttingen UTEM employs nano-localized linear photoemission from a Schottky emitter, which enables operation with freely tunable temporal structure, from continuous wave to femtosecond pulsed mode. Using this emission mechanism, we achieve record pulse properties in ultrafast electron microscopy of 9Å focused beam diameter, 200fs pulse duration and 0.6eV energy width. We illustrate the possibility to conduct ultrafast imaging, diffraction, holography and spectroscopy with this instrument and also discuss opportunities to harness quantum coherent interactions between intense laser fields and free-electron beams.
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Affiliation(s)
- Armin Feist
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Nora Bach
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Nara Rubiano da Silva
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Thomas Danz
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Marcel Möller
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Katharina E Priebe
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Till Domröse
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - J Gregor Gatzmann
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Stefan Rost
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Jakob Schauss
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Stefanie Strauch
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Reiner Bormann
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Murat Sivis
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany
| | - Sascha Schäfer
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany.
| | - Claus Ropers
- 4th Physical Institute - Solids and Nanostructures, University of Göttingen, Göttingen, Germany.
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