1
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Tetteh N, Parshotam S, Gibbs JM. Separating Hofmeister Trends in Stern and Diffuse Layers at a Charged Interface. J Phys Chem Lett 2024; 15:9113-9121. [PMID: 39206708 DOI: 10.1021/acs.jpclett.4c01792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Understanding the role of pH and ions on the electrical double layer (EDL) at charged mineral oxide/aqueous interfaces remains crucial in modeling environmental and industrial processes. Yet the simultaneous contribution of pH and specific ion effects (SIEs) on the different layers of the EDL remains unknown. Here, we utilize zeta potential measurements, vibrational sum frequency generation, and the maximum entropy method to ascertain the detailed structure of the Stern and diffuse regions of the EDL at the silica/water interface with varying pH values for different alkali chlorides. Both at pH 2, when the surface is nearly neutral, and at pH 12, when the surface is highly charged, we observe that Li+ and Na+ disrupt while Cs+ enhances existing water structures within the Stern layer. Moreover, the SIE trends for the diffuse and Stern layers are opposite to one another at pH 2 (in the amount of ordered water) and at pH 12 (in the amount of net oriented water). Finally, we observe an inversion in Hofmeister (SIE) trends at low and high pH in the zeta that impacts the diffuse layer structure. These results indicate that SIEs play critical yet separable roles in governing both the electrostatic and water-structuring capabilities of the EDL.
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Affiliation(s)
- Nathaniel Tetteh
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Shyam Parshotam
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Julianne M Gibbs
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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2
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Schindl A, Hagen ML, Cooley I, Jäger CM, Warden AC, Zelzer M, Allers T, Croft AK. Ion-combination specific effects driving the enzymatic activity of halophilic alcohol dehydrogenase 2 from Haloferax volcanii in aqueous ionic liquid solvent mixtures. RSC SUSTAINABILITY 2024; 2:2559-2580. [PMID: 39211508 PMCID: PMC11353702 DOI: 10.1039/d3su00412k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 06/30/2024] [Indexed: 09/04/2024]
Abstract
Biocatalysis in ionic liquids enables novel routes for bioprocessing. Enzymes derived from extremophiles promise greater stability and activity under ionic liquid (IL) influence. Here, we probe the enzyme alcohol dehydrogenase 2 from the halophilic archaeon Haloferax volcanii in thirteen different ion combinations for relative activity and analyse the results against molecular dynamics (MD) simulations of the same IL systems. We probe the ionic liquid property space based on ion polarizability and molecular electrostatic potential. Using the radial distribution functions, survival probabilities and spatial distribution functions of ions, we show that cooperative ion-ion interactions determine ion-protein interactions, and specifically, strong ion-ion interactions equate to higher enzymatic activity if neither of the ions interact strongly with the protein surface. We further demonstrate a tendency for cations interacting with the protein surface to be least detrimental to enzymatic activity if they show a low polarizability when combined with small hydrophilic anions. We also find that the IL ion influence is not mitigated by the surplus of negatively charged residues of the halophilic enzyme. This is shown by free energy landscape analysis in root mean square deviation and distance variation plots of active site gating residues (Trp43 and His273) demonstrating no protection of specific structural elements relevant to preserving enzymatic activity. On the other hand, we observe a general effect across all IL systems that a tight binding of water at acidic residues is preferentially interrupted at these residues through the increased presence of potassium ions. Overall, this study demonstrates a co-ion interaction dependent influence on allosteric surface residues controlling the active/inactive conformation of halophilic alcohol dehydrogenase 2 and the necessity to engineer ionic liquid systems for enzymes that rely on the integrity of functional surface residues regardless of their halophilicity or thermophilicity for use in bioprocessing.
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Affiliation(s)
- Alexandra Schindl
- Sustainable Process Technologies Group, Department of Chemical and Environmental Engineering, University of Nottingham Nottingham NG7 2RD UK
- School of Pharmacy, University of Nottingham, University Park Campus Nottingham NG7 2RD UK
- School of Life Sciences, University of Nottingham, Queen's Medical Centre Nottingham NG7 2UH UK
- School of Molecular and Cellular Biology, University of Leeds Leeds LS2 9JT UK
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds Leeds LS2 9JT UK
| | - M Lawrence Hagen
- Sustainable Process Technologies Group, Department of Chemical and Environmental Engineering, University of Nottingham Nottingham NG7 2RD UK
| | - Isabel Cooley
- Department of Chemical Engineering, Loughborough University LE11 3TU UK
| | - Christof M Jäger
- Sustainable Process Technologies Group, Department of Chemical and Environmental Engineering, University of Nottingham Nottingham NG7 2RD UK
- Data Science and Modelling, Pharmaceutical Sciences, R&D, AstraZeneca Gothenburg Pepparedsleden 1 SE-431 83 Mölndal Sweden
| | - Andrew C Warden
- CSIRO Environment, Commonwealth Scientific and Industrial Research Organization (CSIRO), Research and Innovation Park Acton Canberra ACT 2600 Australia
- Advanced Engineering Biology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Research and Innovation Park Acton Canberra ACT 2600 Australia
| | - Mischa Zelzer
- School of Pharmacy, University of Nottingham, University Park Campus Nottingham NG7 2RD UK
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre Nottingham NG7 2UH UK
| | - Anna K Croft
- Department of Chemical Engineering, Loughborough University LE11 3TU UK
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3
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Duenas-Herrera M, Bonthuis DJ, Loche P, Netz RR, Scalfi L. Force field for halide and alkali ions in water based on single-ion and ion-pair thermodynamic properties for a wide range of concentrations. J Chem Phys 2024; 161:074506. [PMID: 39158049 DOI: 10.1063/5.0217998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 07/20/2024] [Indexed: 08/20/2024] Open
Abstract
A classical non-polarizable force field for the common halide (F-, Cl-, Br-, and I-) and alkali (Li+, Na+, K+, and Cs+) ions in SPC/E water is presented. This is an extension of the force field developed by Loche et al. for Na+, K+, Cl-, and Br- (JPCB 125, 8581-8587, 2021): in the present work, we additionally optimize Lennard-Jones parameters for Li+, I-, Cs+, and F- ions. Li+ and F- are particularly challenging ions to model due to their small size. The force field is optimized with respect to experimental solvation free energies and activity coefficients, which are the necessary and sufficient quantities to accurately reproduce the electrolyte thermodynamics. Good agreement with experimental reference data is achieved for a wide range of concentrations (up to 4 mol/l). We find that standard Lorentz-Berthelot combination rules are sufficient for all ions except F-, for which modified combination rules are necessary. With the optimized parameters, we show that, although the force field is only optimized based on thermodynamic properties, structural properties are reproduced quantitatively, while ion diffusion coefficients are in qualitative agreement with experimental values.
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Affiliation(s)
- Maria Duenas-Herrera
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Douwe Jan Bonthuis
- Institute of Theoretical and Computational Physics, Graz University of Technology, Graz, Austria
| | - Philip Loche
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Laboratory of Computational Science and Modeling, IMX, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland
| | - Roland R Netz
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Laura Scalfi
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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4
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Smirnov KS. Effects of Surface Charge Distribution and Electrolyte Ions on the Nonlinear Spectra of Model Solid-Water Interfaces. Molecules 2024; 29:3758. [PMID: 39202839 PMCID: PMC11356812 DOI: 10.3390/molecules29163758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/31/2024] [Accepted: 08/01/2024] [Indexed: 09/03/2024] Open
Abstract
Molecular dynamics simulations of model charged solid/water interfaces were carried out to provide insight about the relationship between the second-order nonlinear susceptibility χ(2) and the structure of the interfacial water layer. The results of the calculations reveal that the density fluctuations of water extend to about 12 Å from the surface regardless of the system, while the orientational ordering of molecules is long-ranged and is sensitive to the presence of electrolytes. The charge localization on the surface was found to affect only the high-frequency part of the Im[χ(2)] spectrum, and the addition of salt has very little effect on the spectrum of the first water layer. For solid/neat water interfaces, the spectroscopically active part of the liquid phase has a thickness largely exceeding the region of density fluctuations, and this long-ranged nonlinear activity is mediated by the electric field of the molecules. The electrolyte ions and their hydration shells act in a destructive way on the molecular field. This effect, combined with the screening of the surface charge by ions, drastically reduces the thickness of the spectroscopic diffuse layer. There is an electrolyte concentration at which the nonlinear response of the diffuse layer is suppressed and the χ(2) spectrum of the interface essentially coincides with that of the first water layer.
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Affiliation(s)
- Konstantin S Smirnov
- Univ. Lille, CNRS, UMR 8516 - LASIRe - Laboratoire Avancé de Spectroscopie pour les Interactions la Réactivité et l'Environnement, F-59000 Lille, France
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5
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Kim J, Rotenberg B. Donnan equilibrium in charged slit-pores from a hybrid nonequilibrium molecular dynamics/Monte Carlo method with ions and solvent exchange. J Chem Phys 2024; 161:054107. [PMID: 39087531 DOI: 10.1063/5.0220913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 07/14/2024] [Indexed: 08/02/2024] Open
Abstract
Ion partitioning between different compartments (e.g., a porous material and a bulk solution reservoir), known as Donnan equilibrium, plays a fundamental role in various contexts such as energy, environment, or water treatment. The linearized Poisson-Boltzmann (PB) equation, capturing the thermal motion of the ions with mean-field electrostatic interactions, is practically useful to understand and predict ion partitioning, despite its limited applicability to conditions of low salt concentrations and surface charge densities. Here, we investigate the Donnan equilibrium of coarse-grained dilute electrolytes confined in charged slit-pores in equilibrium with a reservoir of ions and solvent. We introduce and use an extension to confined systems of a recently developed hybrid nonequilibrium molecular dynamics/grand canonical Monte Carlo simulation method ("H4D"), which enhances the efficiency of solvent and ion-pair exchange via a fourth spatial dimension. We show that the validity range of linearized PB theory to predict the Donnan equilibrium of dilute electrolytes can be extended to highly charged pores by simply considering renormalized surface charge densities. We compare with simulations of implicit solvent models of electrolytes and show that in the low salt concentrations and thin electric double layer limit considered here, an explicit solvent has a limited effect on the Donnan equilibrium and that the main limitations of the analytical predictions are not due to the breakdown of the mean-field description but rather to the charge renormalization approximation, because it only focuses on the behavior far from the surfaces.
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Affiliation(s)
- Jeongmin Kim
- Department of Energy Engineering, Korea Institute of Energy Technology (KENTECH), Naju 58330, Republic of Korea
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
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6
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Liu C, Qin X, Yu C, Guo Y, Zhang Z. Probing the adsorption configuration of methanol at a charged air/aqueous interface using nonlinear spectroscopy. Phys Chem Chem Phys 2024; 26:14336-14344. [PMID: 38699833 DOI: 10.1039/d3cp06317h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Investigating the effects of electrolyte ions on the adsorption configuration of methanol at a charged interface is important for studying the interface structure of electrolyte solutions and the oxidation mechanism of methanol in fuel cells. This study uses sum frequency generation (SFG) and heterodyne-detected second harmonic generation (HD-SHG) to investigate the adsorption configuration of methanol at the air/aqueous interface of 0.1 M NaClO4 solution, 0.1 M HClO4 solution and pure water. The results elucidate that the ion effect in the electrolyte solution affects the interface's charged state and the methanol's adsorption conformation at the interface. The negatively charged surface of the 0.1 M NaClO4 solution and the positively charged surface of the 0.1 M HClO4 solution arise from the corresponding specific ionic effects of the electrolyte solution. The orientation angle of methyl with respect to the surface normal is 43.4° ± 0.1° at the 0.1 M NaClO4 solution surface and 21.5° ± 0.2° at the 0.1 M HClO4 solution surface. Examining these adsorption configurations in detail, we find that at the negatively charged surface the inclined orientation angle (43.4°) of methanol favors the hydroxymethyl production by breaking the C-H bond, while at the positively charged surface the upright orientation angle (21.5°) of methanol promotes the methoxy formation by breaking the O-H bond. These findings not only illuminate the intricate ion effects on small organic molecules but also contribute to a molecular-level comprehension of the oxidation mechanism of methanol at electrode interfaces.
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Affiliation(s)
- Caihe Liu
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xujin Qin
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Changhui Yu
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Guo
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Zhang
- Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of the Chinese Academy of Sciences, Beijing 100049, China
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7
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Raji F, Nguyen NN, Nguyen CV, Nguyen AV. Lead (II) ions enable the ion-specific effects of monovalent anions on the molecular structure and interactions at silica/aqueous interfaces. J Colloid Interface Sci 2024; 662:653-662. [PMID: 38367582 DOI: 10.1016/j.jcis.2024.02.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/07/2024] [Accepted: 02/11/2024] [Indexed: 02/19/2024]
Abstract
HYPOTHESIS The adsorption of heavy metal ions such as Pb(II) onto negatively charged minerals such as silica is expected to alter the structure and the interactions at the silica/aqueous interfaces. Besides the solution pH, the inner-sphere sorption of Pb(II) is expected to regulate the surface charge/potential, hypothesized to control the actions of monovalent anions in the aqueous environment. These complex pictures can be probed directly using surface-sensitive sum-frequency generation (SFG) spectroscopy. EXPERIMENTS The pH-dependent water structure within the double layer at silica/aqueous interfaces under the influence of different ions was examined using SFG. The recorded SFG spectra were deconvoluted into the Stern layer (SL) and diffuse layer (DL) using the maximum entropy method in conjunction with the electrical double-layer theory. FINDINGS Standalone monovalent sodium salts do not exhibit ion-specific effects on the silica/aqueous interfaces. However, the mixture of Pb(II) species and each of these salts display profound ion-specific effects on the structure of silica/aqueous interfaces, indicating the role of Pb(II) as an enabler of the ion-specificity of the investigated monovalent anions. The interesting effect arises from a complex interplay between the physical processes (i.e., electrostatic interactions, screening effects, etc.) and chemical processes such as the hydrolysis of Pb(II) ions, ion complexation, protonation and deprotonation of the surface silanol group.
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Affiliation(s)
- Foad Raji
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Ngoc N Nguyen
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Cuong V Nguyen
- Department of Water and Environmental Regulation, Joondalup, WA 6027, Australia
| | - Anh V Nguyen
- School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia
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8
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Lee SE, Carr AJ, Kumal RR, Uysal A. Monovalent ion-graphene oxide interactions are controlled by carboxylic acid groups: Sum frequency generation spectroscopy studies. J Chem Phys 2024; 160:084707. [PMID: 38415831 DOI: 10.1063/5.0189203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/05/2024] [Indexed: 02/29/2024] Open
Abstract
Graphene oxide (GO) is a two-dimensional, mechanically strong, and chemically tunable material for separations. Elucidating GO-ion-water interactions at the molecular scale is highly important for predictive understanding of separation systems. However, direct observations of the nanometer region by GO surfaces under operando conditions are not trivial. Therefore, thin films of GO at the air/water interface can be used as model systems. With this approach, we study the effects of alkali metal ions on water organization near graphene oxide films at the air/water interface using vibrational sum frequency generation (SFG) spectroscopy. We also use an arachidic acid Langmuir monolayer as a benchmark for a pure carboxylic acid surface. Theoretical modeling of the concentration-dependent sum frequency signal from graphene oxide and arachidic acid surfaces reveals that the adsorption of monovalent ions is mainly controlled by the carboxylic acid groups on graphene oxide. An in-depth analysis of sum frequency spectra reveals at least three distinct water populations with different hydrogen bonding strengths. The origin of each population can be identified from concentration dependent variations of their SFG signal. Interestingly, an interfacial water structure seemed mostly insensitive to the character of the alkali cation, in contrast to similar studies conducted at the silica/water interface. However, we observed an ion-specific effect with lithium, whose strong hydration prevented direct interactions with the graphene oxide film.
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Affiliation(s)
- Seung Eun Lee
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Amanda J Carr
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Raju R Kumal
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ahmet Uysal
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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9
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Olivieri JF, Hynes JT, Laage D. Water dynamics and sum-frequency generation spectra at electrode/aqueous electrolyte interfaces. Faraday Discuss 2024; 249:289-302. [PMID: 37791579 DOI: 10.1039/d3fd00103b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The dynamics of water at interfaces between an electrode and an electrolyte is essential for the transport of redox species and for the kinetics of charge transfer reactions next to the electrode. However, while the effects of electrode potential and ion concentration on the electric double layer structure have been extensively studied, a comparable understanding of dynamical aspects is missing. Interfacial water dynamics presents challenges since it is expected to result from the complex combination of water-water, water-electrode and water-ion interactions. Here we perform molecular dynamics simulations of aqueous NaCl solutions at the interface with graphene electrodes, and examine the impact of both ion concentration and electrode potential on interfacial water reorientational dynamics. We show that for all salt concentrations water dynamics exhibits strongly asymmetric behavior: it slows down at increasingly positively charged electrodes but it accelerates at increasingly negatively charged electrodes. At negative potentials water dynamics is determined mostly by the electrode potential value, but in contrast at positive potentials it is governed both by ion-water and electrode-water interactions. We show how these strikingly different behaviors are determined by the interfacial hydrogen-bond network structure and by the ions' surface affinity. Finally, we indicate how the structural rearrangements impacting water dynamics can be probed via vibrational sum-frequency generation spectroscopy.
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Affiliation(s)
- Jean-François Olivieri
- PASTEUR, Department of Chemistry, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - James T Hynes
- PASTEUR, Department of Chemistry, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Damien Laage
- PASTEUR, Department of Chemistry, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
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10
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Xu P, Wang R, Zhang H, Carnevale V, Borguet E, Suntivich J. Cation Modifies Interfacial Water Structures on Platinum during Alkaline Hydrogen Electrocatalysis. J Am Chem Soc 2024; 146:2426-2434. [PMID: 38228289 DOI: 10.1021/jacs.3c09128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The molecular details of an electrocatalytic interface play an essential role in the production of sustainable fuels and value-added chemicals. Many electrochemical reactions exhibit strong cation-dependent activities, but how cations affect reaction kinetics is still elusive. We report the effect of cations (K+, Li+, and Ba2+) on the interfacial water structure using second-harmonic generation (SHG) and classical molecular dynamics (MD) simulation. The second- (χH2O(2)) and third-order (χH2O(3)) optical susceptibilities of water on Pt are smaller in the presence of Ba2+ compared to those of K+, suggesting that cations can affect the interfacial water orientation. MD simulation reproduces experimental SHG observations and further shows that the competition between cation hydration and interfacial water alignment governs the net water orientation. The impact of cations on interfacial water supports a cation hydration-mediated mechanism for hydrogen electrocatalysis; i.e., the reaction occurs via water dissociation followed by cation-assisted hydroxide/water exchange on Pt. Our study highlights the role of interfacial water in electrocatalysis and how innocent additives (such as cations) can affect the local electrochemical environment.
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Affiliation(s)
- Pengtao Xu
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Ruiyu Wang
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
- Center for Complex Materials from First-Principles (CCM), Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Haojian Zhang
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, United States
| | - Vincenzo Carnevale
- Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States
- Department of Biology, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Eric Borguet
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
- Center for Complex Materials from First-Principles (CCM), Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Jin Suntivich
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14850, United States
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11
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Becker M, Loche P, Rezaei M, Wolde-Kidan A, Uematsu Y, Netz RR, Bonthuis DJ. Multiscale Modeling of Aqueous Electric Double Layers. Chem Rev 2024; 124:1-26. [PMID: 38118062 PMCID: PMC10785765 DOI: 10.1021/acs.chemrev.3c00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 11/17/2023] [Accepted: 11/30/2023] [Indexed: 12/22/2023]
Abstract
From the stability of colloidal suspensions to the charging of electrodes, electric double layers play a pivotal role in aqueous systems. The interactions between interfaces, water molecules, ions and other solutes making up the electrical double layer span length scales from Ångströms to micrometers and are notoriously complex. Therefore, explaining experimental observations in terms of the double layer's molecular structure has been a long-standing challenge in physical chemistry, yet recent advances in simulations techniques and computational power have led to tremendous progress. In particular, the past decades have seen the development of a multiscale theoretical framework based on the combination of quantum density functional theory, force-field based simulations and continuum theory. In this Review, we discuss these theoretical developments and make quantitative comparisons to experimental results from, among other techniques, sum-frequency generation, atomic-force microscopy, and electrokinetics. Starting from the vapor/water interface, we treat a range of qualitatively different types of surfaces, varying from soft to solid, from hydrophilic to hydrophobic, and from charged to uncharged.
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Affiliation(s)
| | - Philip Loche
- Fachbereich
Physik, Freie Universität Berlin, 14195 Berlin, Germany
- Laboratory
of Computational Science and Modeling, IMX, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Majid Rezaei
- Fachbereich
Physik, Freie Universität Berlin, 14195 Berlin, Germany
- Institute
of Theoretical Chemistry, Ulm University, 89081 Ulm, Germany
| | | | - Yuki Uematsu
- Department
of Physics and Information Technology, Kyushu
Institute of Technology, 820-8502 Iizuka, Japan
- PRESTO,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Roland R. Netz
- Fachbereich
Physik, Freie Universität Berlin, 14195 Berlin, Germany
| | - Douwe Jan Bonthuis
- Institute
of Theoretical and Computational Physics, Graz University of Technology, 8010 Graz, Austria
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12
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Tan J, Wang M, Zhang J, Ye S. Determination of the Thickness of Interfacial Water by Time-Resolved Sum-Frequency Generation Vibrational Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18573-18580. [PMID: 38051545 DOI: 10.1021/acs.langmuir.3c02906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The physics and chemistry of a charged interface are governed by the structure of the electrical double layer (EDL). Determination of the interfacial water thickness (diw) of the charged interface is crucial to quantitatively describe the EDL structure, but it can be utilized with very scarce experimental methods. Here, we propose and verify that the vibrational relaxation time (T1) of the OH stretching mode at 3200 cm-1, obtained by time-resolved sum frequency generation vibrational spectroscopy with ssp polarizations, provides an effective tool to determine diw. By investigating the T1 values at the SiO2/NaCl solution interface, we established a time-space (T1-diw) relationship. We find that water has a T1 lifetime of ≥0.5 ps for diw ≤ 3 Å, while it displays bulk-like dynamics with T1 ≤ 0.2 ps for diw ≥ 9 Å. T1 decreases as diw increases from ∼3 Å to 9 Å. The hydration water at the DPPG lipid bilayer and LK15β protein interfaces has a thickness of ≥9 Å and shows a bulk-like feature. The time-space relationship will provide a novel tool to pattern the interfacial topography and heterogeneity in Ångstrom-depth resolution by imaging the T1 values.
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Affiliation(s)
- Junjun Tan
- Hefei National Research Center for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
| | - Mengmeng Wang
- Hefei National Research Center for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Jiahui Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Shuji Ye
- Hefei National Research Center for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
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Sam S, Sung S, Kim D. Sensitive Detection of Biomolecular Adsorption by a Low-Density Surfactant Layer Using Sum-Frequency Vibrational Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:17412-17419. [PMID: 38050679 DOI: 10.1021/acs.langmuir.3c02546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Small molecules or proteins interact with a biomembrane in various ways for molecular recognition, structure stabilization, and transmembrane signaling. In this study, 1,2-dipalmitoyl-3-trimethylammonium-propane (DPTAP), having a choline group, was used to investigate this interaction by using sum-frequency vibrational spectroscopy. The sum-frequency spectrum characteristic of a neat monolayer changed to that of a bare air/water interface at a larger molecular area of the DPTAP molecules due to local laser heating. Upon introduction of the aromatic molecules in the subphase at around 120 Å2 per molecule, the sum-frequency signal suddenly reappeared due to molecular adhesion, and this was utilized to probe the adsorption of the aromatic ring molecules in the water subphase to the choline headgroup of the DPTAP by cation-π interaction. The onset concentrations of this sum-frequency signal change allowed a comparison of the relative interaction strengths between different aromatic molecules. A zwitterionic surfactant molecule (DPPC) was found to interact weakly compared to the cationic DPTAP molecule.
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Affiliation(s)
- Sokhuoy Sam
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul, 04107, Korea
| | - Siheon Sung
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul, 04107, Korea
| | - Doseok Kim
- Department of Physics, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul, 04107, Korea
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Nayak S, Kumal RR, Lee SE, Uysal A. Elucidating Trivalent Ion Adsorption at Floating Carboxylic Acid Monolayers: Charge Reversal or Water Reorganization? J Phys Chem Lett 2023; 14:3685-3690. [PMID: 37036360 DOI: 10.1021/acs.jpclett.3c00225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
We study the adsorption of trivalent neodymium on floating arachidic acid films at the air-water interface by two complementary surface specific probes, sum frequency generation spectroscopy and X-ray fluorescence near total reflection. In the absence of background ions, neodymium ions compensate for the surface charge of the arachidic acid film at a bulk concentration of 50 μM without any charge reversal. Increasing the bulk concentration to 1 mM does not change the neodymium surface coverage but affects the interfacial water structure significantly. In the presence of a high concentration of NaCl, there is overcharging at 1 mM Nd3+, i.e., 30% more Nd3+ than needed to compensate for the surface charge. These results show that the total coverage of neodymium ions is not enough to describe the complete picture at the interface, and interfacial water and ion coverage needs to be considered together to understand more complex ion adsorption and transport processes.
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Affiliation(s)
- Srikanth Nayak
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Raju R Kumal
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Seung Eun Lee
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ahmet Uysal
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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Penschke C, Thomas J, Bertram C, Michaelides A, Morgenstern K, Saalfrank P, Bovensiepen U. Hydration at Highly Crowded Interfaces. PHYSICAL REVIEW LETTERS 2023; 130:106202. [PMID: 36962030 DOI: 10.1103/physrevlett.130.106202] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/08/2022] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
Understanding the molecular and electronic structure of solvated ions at surfaces requires an analysis of the interactions between the surface, the ions, and the solvent environment on equal footing. Here, we tackle this challenge by exploring the initial stages of Cs^{+} hydration on a Cu(111) surface by combining experiment and theory. Remarkably, we observe "inside-out" solvation of Cs^{+} ions, i.e., their preferential location at the perimeter of the water clusters on the metal surface. In addition, water-Cs complexes containing multiple Cs^{+} ions are observed to form at these surfaces. Established models based on maximum ion-water coordination and conventional solvation models cannot account for this situation, and the complex interplay of microscopic interactions is the key to a fundamental understanding.
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Affiliation(s)
- Christopher Penschke
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - John Thomas
- Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, D-47048 Duisburg, Germany
| | - Cord Bertram
- Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, D-47048 Duisburg, Germany
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Angelos Michaelides
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Karina Morgenstern
- Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Peter Saalfrank
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
- Department of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - Uwe Bovensiepen
- Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, D-47048 Duisburg, Germany
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Zheng RH, Wei WM, Zhang SC. Sum-frequency vibrational spectroscopy of centrosymmetric molecule at interfaces. J Chem Phys 2023; 158:074701. [PMID: 36813719 DOI: 10.1063/5.0139895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The centrosymmetric benzene molecule has zero first-order electric dipole hyperpolarizability, which results in no sum-frequency vibrational spectroscopy (SFVS) signal at interfaces, but it shows very strong SFVS experimentally. We perform a theoretical study on its SFVS, which is in good agreement with the experimental results. Its strong SFVS mainly comes from the interfacial electric quadrupole hyperpolarizability rather than the symmetry-breaking electric dipole, bulk electric quadrupole, and interfacial and bulk magnetic dipole hyperpolarizabilities, which provides a novel and completely unconventional point of view.
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Affiliation(s)
- Ren-Hui Zheng
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, People's Republic of China
| | - Wen-Mei Wei
- Department of Chemistry, College of Basic Medicine, Anhui Medical University, Hefei, Anhui 230032, People's Republic of China
| | - Shuo-Cang Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, People's Republic of China
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