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Ilgen AG, Borguet E, Geiger FM, Gibbs JM, Grassian VH, Jun YS, Kabengi N, Kubicki JD. Bridging molecular-scale interfacial science with continuum-scale models. Nat Commun 2024; 15:5326. [PMID: 38909017 PMCID: PMC11193788 DOI: 10.1038/s41467-024-49598-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 06/07/2024] [Indexed: 06/24/2024] Open
Abstract
Solid-water interfaces are crucial for clean water, conventional and renewable energy, and effective nuclear waste management. However, reflecting the complexity of reactive interfaces in continuum-scale models is a challenge, leading to oversimplified representations that often fail to predict real-world behavior. This is because these models use fixed parameters derived by averaging across a wide physicochemical range observed at the molecular scale. Recent studies have revealed the stochastic nature of molecular-level surface sites that define a variety of reaction mechanisms, rates, and products even across a single surface. To bridge the molecular knowledge and predictive continuum-scale models, we propose to represent surface properties with probability distributions rather than with discrete constant values derived by averaging across a heterogeneous surface. This conceptual shift in continuum-scale modeling requires exponentially rising computational power. By incorporating our molecular-scale understanding of solid-water interfaces into continuum-scale models we can pave the way for next generation critical technologies and novel environmental solutions.
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Affiliation(s)
- Anastasia G Ilgen
- Geochemistry Department, Sandia National Laboratories, Albuquerque, NM, 87123, USA.
| | - Eric Borguet
- Department of Chemistry, Temple University, Philadelphia, PA, 19122, USA
| | - Franz M Geiger
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Julianne M Gibbs
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry, University of California, La Jolla, CA, 92093, USA
| | - Young-Shin Jun
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Nadine Kabengi
- Department of Geosciences, Georgia State University, Atlanta, GA, 30302, USA
| | - James D Kubicki
- Department of Earth, Environmental and Resource Sciences, The University of Texas at El Paso, El Paso, TX, 79968, USA
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2
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Mapile AN, LeRoy MA, Fabrizio K, Scatena LF, Brozek CK. The Surface of Colloidal Metal-Organic Framework Nanoparticles Revealed by Vibrational Sum Frequency Scattering Spectroscopy. ACS NANO 2024; 18:13406-13414. [PMID: 38722052 DOI: 10.1021/acsnano.4c03758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Solvation shells strongly influence the interfacial chemistry of colloidal systems, from the activity of proteins to the colloidal stability and catalysis of nanoparticles. Despite their fundamental and practical importance, solvation shells have remained largely undetected by spectroscopy. Furthermore, their ability to assemble at complex but realistic interfaces with heterogeneous and rough surfaces remains an open question. Here, we apply vibrational sum frequency scattering spectroscopy (VSFSS), an interface-specific technique, to colloidal nanocrystals with porous metal-organic frameworks (MOFs) as a case study. Due to the porous nature of the solvent-particle boundary, MOF particles challenge conventional models of colloidal and interfacial chemistry. Their multiweek colloidal stability in the absence of conventional surface ligands suggests that stability may arise in part from solvation forces. Spectra of colloidally stable Zn(2-methylimidazolate)2 (ZIF-8) in polar solvents indicate the presence of ordered solvation shells, solvent-metal binding, and spontaneous ordering of organic bridging linkers within the MOF. These findings help explain the unexpected colloidal stability of MOF colloids, while providing a roadmap for applying VSFSS to wide-ranging colloidal nanocrystals in general.
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Affiliation(s)
- Ashley N Mapile
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States
| | - Michael A LeRoy
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States
| | - Kevin Fabrizio
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States
| | - Lawrence F Scatena
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States
| | - Carl K Brozek
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon, Eugene, Oregon 97403, United States
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3
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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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4
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Uddin MM, Azam MS, Hore DK. Variable-Angle Surface Spectroscopy Reveals the Water Structure in the Stern Layer at Charged Aqueous Interfaces. J Am Chem Soc 2024; 146:11756-11763. [PMID: 38600700 DOI: 10.1021/jacs.3c14836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
At charged aqueous interfaces, the second-order nonlinear optical response originates from water molecules within the diffuse part of the electrical double layer, which are ordered by the surface field and from water that additionally experiences chemical and physical interactions with the surface in the Stern layer. These two environments can either reinforce or diminish the overall signal and can be disentangled by varying the coherence length of their interaction with external laser fields. Here, we demonstrate a method in which the angle of incidence is varied to afford a significant change in the coherence length. When this technique was applied to the silica-water interface, it was observed that water molecules in the Stern and diffuse layers direct their hydrogen atoms toward the mineral surface at a low ionic strength and neutral pH. A decrease in the signal with increasing ionic strength is attributed to hydrated cation adsorption that competes with free water for deprotonated silanol sites.
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Affiliation(s)
- Md Mosfeq Uddin
- Department of Chemistry, University of Victoria, Victoria V8W 3 V6, British Columbia, Canada
| | - Md Shafiul Azam
- Department of Chemistry, University of Victoria, Victoria V8W 3 V6, British Columbia, Canada
| | - Dennis K Hore
- Department of Chemistry, University of Victoria, Victoria V8W 3 V6, British Columbia, Canada
- Department of Computer Science, University of Victoria, Victoria V8W 3P6, British Columbia, Canada
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Lyu D, Märker K, Zhou Y, Zhao EW, Gunnarsdóttir AB, Niblett SP, Forse AC, Grey CP. Understanding Sorption of Aqueous Electrolytes in Porous Carbon by NMR Spectroscopy. J Am Chem Soc 2024; 146:9897-9910. [PMID: 38560816 PMCID: PMC11009947 DOI: 10.1021/jacs.3c14807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
Ion adsorption at solid-water interfaces is crucial for many electrochemical processes involving aqueous electrolytes including energy storage, electrochemical separations, and electrocatalysis. However, the impact of the hydronium (H3O+) and hydroxide (OH-) ions on the ion adsorption and surface charge distributions remains poorly understood. Many fundamental studies of supercapacitors focus on non-aqueous electrolytes to avoid addressing the role of functional groups and electrolyte pH in altering ion uptake. Achieving microscopic level characterization of interfacial mixed ion adsorption is particularly challenging due to the complex ion dynamics, disordered structures, and hierarchical porosity of the carbon electrodes. This work addresses these challenges starting with pH measurements to quantify the adsorbed H3O+ concentrations, which reveal the basic nature of the activated carbon YP-50F commonly used in supercapacitors. Solid-state NMR spectroscopy is used to study the uptake of lithium bis(trifluoromethanesulfonyl)-imide (LiTFSI) aqueous electrolyte in the YP-50F carbon across the full pH range. The NMR data analysis highlights the importance of including the fast ion-exchange processes for accurate quantification of the adsorbed ions. Under acidic conditions, more TFSI- ions are adsorbed in the carbon pores than Li+ ions, with charge compensation also occurring via H3O+ adsorption. Under neutral and basic conditions, when the carbon's surface charge is close to zero, the Li+ and TFSI- ions exhibit similar but lower affinities toward the carbon pores. Our experimental approach and evidence of H3O+ uptake in pores provide a methodology to relate the local structure to the function and performance in a wide range of materials for energy applications and beyond.
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Affiliation(s)
- Dongxun Lyu
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | | | - Yuning Zhou
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | | | | | - Samuel P. Niblett
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Alexander C. Forse
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Clare P. Grey
- Yusuf Hamied Department of
Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
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6
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Kim S, Ji S, Jeong S, Yang H, Lee S, Choi H, Li OL. Switching Electric Double Layer Potential by Phase Structure Control for Advanced Oxygen Reduction Reaction of Cobalt@Nitrogen Doped Carbon Core-Shell. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307483. [PMID: 38150612 DOI: 10.1002/smll.202307483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/04/2023] [Indexed: 12/29/2023]
Abstract
The key to design an advanced oxygen reduction reaction (ORR) electrocatalyst is a well-balance between the adsorption and desorption of oxygen intermediates. This study systematically evaluated the ORR activity of HCP and FCC cobalt core-shell cobalt/N-doped carbon (Cobalt@NC) catalyst via theoretical and experimental studies. The electronic structure calculations using density functional theory (DFT) calculations revealed that the ORR activity of carbon layer can be improved by 1) switching the electrostatic potential in the electrical double layer due to the polarization induced at the carbon-cobalt interface and 2) modulating the electron population in the bonding orbital in the C-O bonds in an ORR. The results revealed that an O atom is bounded stronger to the outer NC shell with FCC Cobalt than HCP Cobalt, which hindered the desorption steps of OH*. Experimentally, plasma-engineered HCP Cobalt@NC also showed remarkably advanced performance toward ORR compared to that FCC Cobalt@NC. The kinetic current density of HCP Cobalt@NC at 0.85 V versus RHE is calculated as 6.24 mA cm-2, which is six folds higher than FCC Cobalt@NC and even outperform 20 wt.% Pt/C. In a practical Aluminium-air battery, HCP Cobalt@NC also exhibited slightly higher peak power density (110.57 mW cm-2) compared to 20 wt.% Pt/C.
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Affiliation(s)
- Seonghee Kim
- School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Seulgi Ji
- Institute of Inorganic Chemistry, University of Cologne, Greinstr. 6, 50939, Cologne, Germany
| | - Soyoon Jeong
- School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Hyeonsu Yang
- School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
- Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-Koen, Kasuga-shi, Fukuoka, 816-8580, Japan
| | - Sungho Lee
- School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Heechae Choi
- Institute of Inorganic Chemistry, University of Cologne, Greinstr. 6, 50939, Cologne, Germany
- Department of Chemistry, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Oi Lun Li
- School of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan, 46241, Republic of Korea
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Olson AL, Alghamdi AO, Geiger FM. NaCl, MgCl 2, and AlCl 3 Surface Coverages on Fused Silica and Adsorption Free Energies at pH 4 from Nonlinear Optics. J Phys Chem A 2024; 128:2162-2168. [PMID: 38470438 DOI: 10.1021/acs.jpca.4c00514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
We employ amplitude- and phase-resolved second harmonic generation experiments to probe interactions of fused silica:aqueous interfaces with Al3+, Mg2+, and Na+ cations at pH 4 and as a function of metal cation concentration. We quantify the second-order nonlinear susceptibility and the total interfacial potential in the presence and absence of a 10 mM screening electrolyte to understand the influence of charge screening on cation adsorption. Strong cation:surface interactions are observed in the absence of the screening electrolyte. The total potential is then employed to estimate the total number of absorbed cations cm-2. The contributions to the total potential from the bound and mobile charges were separated using Gouy-Chapman-Stern model estimates. All three cations bind fully reversibly, indicating physisorption as the mode of interaction. Of the isotherm models tested, the Kd adsorption model fits the data with binding constants of 3-30 and ∼300 mol-1 for the low (<0.1 mM) and high (0.1-3 mM) concentration regimes, corresponding to adsorption free energies of -13 to -18 and -24 kJ mol-1 at room temperature, respectively. The maximum surface coverages are around 1013 cations cm-2, matching the number of deprotonated silanol groups on silica at pH 4. Clear signs of decoupled Stern and diffuse layer nonlinear optical responses are observed and found to be cation-specific.
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Affiliation(s)
- Alyssa L Olson
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
| | - Amani O Alghamdi
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
| | - Franz M Geiger
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60202, United States
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8
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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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9
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Wang Y, Nagata Y, Bonn M. Substrate effect on charging of electrified graphene/water interfaces. Faraday Discuss 2024; 249:303-316. [PMID: 37772472 DOI: 10.1039/d3fd00107e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Graphene, a transparent two-dimensional (2D) conductive electrode, has brought extensive new perspectives and prospects to electrochemical systems, such as chemical sensors, energy storage, and energy conversion devices. In many of these applications, graphene, supported on a substrate, is in contact with an aqueous solution. An increasing number of studies indicate that the substrate, rather than graphene, determines the organization of water in contact with graphene, i.e., the electric double layer (EDL) structure near the electrified graphene, and the wetting behavior of the graphene: the graphene sheet is transparent in terms of its supporting substrate. By applying surface-specific heterodyne-detected sum-frequency generation (HD-SFG) spectroscopy to the silicon dioxide (SiO2)-supported graphene electrode/aqueous electrolyte interface and comparing the data with those for the calcium fluoride (CaF2)-supported graphene [Y. Wang et al., Angew. Chem., Int. Ed., 2023, 62, e202216604], we discuss the impact of the different substrates on the charging of both the graphene and the substrate upon applying potentials. The SiO2-supported graphene shows pseudocapacitive behavior, consistent with the CaF2-supported graphene case, although the surface charges on SiO2 and CaF2 differ substantially. The SiO2 surface is already negatively charged at +0.57 V (vs. Pd/H2), and the negative surface charge is doubled when negative potentials are applied, in contrast with the CaF2 case, where the positive charge is reduced when negative potentials are applied. Interestingly, the charging of the graphene sheet is almost identical between the negatively charged SiO2 surface and positively charged CaF2 surface, demonstrating that the graphene charging is decoupled from the charging of the substrates.
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Affiliation(s)
- Yongkang Wang
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Yuki Nagata
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
| | - Mischa Bonn
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
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10
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Raciti D, Cockayne E, Vinson J, Schwarz K, Hight Walker AR, Moffat TP. SHINERS Study of Chloride Order-Disorder Phase Transition and Solvation of Cu(100). J Am Chem Soc 2024; 146:1588-1602. [PMID: 38170994 DOI: 10.1021/jacs.3c11812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS) and density functional theory (DFT) are used to probe Cl- adsorption and the order-disorder phase transition associated with the c(2 × 2) Cl- adlayer on Cu(100) in acid media. A two-component ν(Cu-Cl) vibrational band centered near 260 ± 1 cm-1 is used to track the potential dependence of Cl- adsorption. The potential dependence of the dominant 260 cm-1 component tracks the coverage of the fluctional c(2 × 2) Cl- phase on terraces in good agreement with the normalized intensity of the c(2 × 2) superstructure rods in prior surface X-ray diffraction (SXRD) studies. As the c(2 × 2) Cl- coverage approaches saturation, a second ν(Cu-Cl) component mode emerges between 290 and 300 cm-1 that coincides with the onset and stiffening of step faceting where Cl- occupies the threefold hollow sites to stabilize the metal kink saturated Cu <100> step edge. The formation of the c(2 × 2) Cl- adlayer is accompanied by the strengthening of ν(O-H) stretching modes in the adjacent non-hydrogen-bonded water at 3600 cm-1 and an increase in hydronium concentration evident in the flanking H2O modes at 3100 cm-1. The polarization of the water molecules and enrichment of hydronium arise from the combination of Cl- anionic character and lateral templating provided by the c(2 × 2) adlayer, consistent with SXRD studies. At negative potentials, Cl- desorption occurs followed by development of a sulfate νs(S═O) band. Below -1.1 V vs Hg/HgSO4, a new 200 cm-1 mode emerges congruent with hydride formation and surface reconstruction reported in electrochemical scanning tunneling microscopy studies.
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Affiliation(s)
- David Raciti
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Eric Cockayne
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - John Vinson
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Kathleen Schwarz
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Angela R Hight Walker
- Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Thomas P Moffat
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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11
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Doan TKD, Umezawa M, Okubo K, Kamimura M, Soga K. Enhancing near-infrared fluorescence intensity and stability of PLGA-b-PEG micelles by introducing Gd-DOTA at the core boundary. J Biomed Mater Res B Appl Biomater 2024; 112:e35327. [PMID: 37732480 DOI: 10.1002/jbm.b.35327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 07/16/2023] [Accepted: 09/07/2023] [Indexed: 09/22/2023]
Abstract
Micelles have been extensively used in biomedicine as potential carriers of hydrophobic fluorescent dyes. Their small diameters can potentially enable them to evade recognition by the reticuloendothelial system, resulting in prolonged circulation. Nevertheless, their lack of stability in physiological environments limits the imaging utility of micelles. In particular, when a dye sensitive to water, such as IR-1061, is encapsulated in the micelle core, the destabilized structure leads to interactions between water and dye, degrading the fluorescence. In this study, we investigated a method to improve micelle stability utilizing the electrical effect of gadolinium (Gd3+ ) and tetraazacyclododecane tetraacetic acid (DOTA), introduced into the micelles. Three micellar structures, one containing a poly(lactic-co-glycolic acid)-block-poly(ethylene glycol) (PLGA-b-PEG) block copolymer, and two other structures, including PLGA-b-PEG with DOTA or Gd-DOTA introduced at the boundary of PLGA and PEG, were prepared with IR-1061 in the core. Structures that contained DOTA at the border of the PLGA core and PEG shell exhibited much higher fluorescence intensity than probes without DOTA. With Gd3+ ions at the DOTA center, fluorescence stability was enhanced remarkably in physiological environments. Most interesting is the finding that fluorescence is enhanced with increased Gd-DOTA concentrations. In conclusion, we found that overall fluorescence and stability are improved by introducing Gd-DOTA at the boundary of the PLGA core and PEG shell. Improving micelle stability is crucial for further biomedical applications of micellar probes such as bimodal fluorescence and magnetic resonance imaging.
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Affiliation(s)
- Thi Kim Dung Doan
- Research Institute for Biomedical Science, Tokyo University of Science, Chiba, Japan
- Division of Functional Imaging, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Kashiwa, Japan
| | - Masakazu Umezawa
- Department of Material Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Kyohei Okubo
- Department of Material Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Masao Kamimura
- Department of Material Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Kohei Soga
- Research Institute for Biomedical Science, Tokyo University of Science, Chiba, Japan
- Department of Material Science and Technology, Tokyo University of Science, Tokyo, Japan
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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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13
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Parshotam S, Rehl B, Brown A, Gibbs JM. Relating the phase in vibrational sum frequency spectroscopy and second harmonic generation with the maximum entropy method. J Chem Phys 2023; 159:204707. [PMID: 38014784 DOI: 10.1063/5.0172667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/03/2023] [Indexed: 11/29/2023] Open
Abstract
Nonlinear optical methods, such as vibrational sum frequency generation (vSFG) and second harmonic generation (SHG), are powerful techniques to study elusive structures at charged buried interfaces. However, for the separation and determination of the Stern and diffuse layer spectra at these charged interfaces, complex vSFG spectra and, hence, the absolute phase need to be retrieved. The maximum entropy method is a useful tool for the retrieval of complex spectra from the intensity spectra; however, one caveat is that an understanding of the error phase is required. Here, for the first time, we provide a physically motivated understanding of the error phase. Determining the error phase from simulated spectra of oscillators with a spectral overlap, we show that for broadband vSFG spectra, such as for the silica/water interface, the diffuse and Stern layers' spectral overlap within the O-H stretching window results in a correlation between the error phase and the phase shift between the responses of these layers. This correlation makes the error phase sensitive to changes in Debye length from varying the ionic strength among other variations at the interface. Furthermore, the change in the magnitude of the error phase can be related to the absolute SHG phase, permitting the use of an error phase model that can utilize the SHG phase to predict the error phase and, hence, the complex vSFG spectra. Finally, we highlight limitations of this model for vSFG spectra with a poor overlap between the diffuse and Stern layer spectra (silica/HOD in D2O system).
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Affiliation(s)
- Shyam Parshotam
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Benjamin Rehl
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Alex Brown
- 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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14
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Lake WR, Meng J, Dawlaty JM, Lian T, Hammes-Schiffer S. Electro-inductive Effect Dominates Vibrational Frequency Shifts of Conjugated Probes on Gold Electrodes. J Am Chem Soc 2023; 145:22548-22554. [PMID: 37795975 DOI: 10.1021/jacs.3c07489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
Interfacial electric fields play a critical role in electrocatalysis and are often characterized by using vibrational probes attached to an electrode surface. Understanding the physical principles dictating the impact of the applied electrode potential on the vibrational probe frequency is important. Herein, a comparative study is performed for two molecular probes attached to a gold electrode. Both probes contain a nitrile (CN) group, but 4-mercaptobenzonitrile (4-MBN) exhibits continuous conjugation from the electrode through the nitrile group, whereas this conjugation is interrupted for 2-(4-mercaptophenyl)acetonitrile (4-MPCN). Periodic density functional theory calculations predict that the CN vibrational frequency shift of the 4-MBN system is dominated by induction, which is a through-bond polarization effect, leading to a strong potential dependence that does not depend significantly on the orientation of the CN bond relative to the surface. In contrast, the CN vibrational frequency shift of the 4-MPCN system is influenced less by induction and more by through-space electric field effects, leading to a weaker potential dependence and a greater orientation dependence. These theoretical predictions were confirmed by surface-enhanced Raman spectroscopy experiments. Balancing through-bond and through-space electrostatic effects may assist in the fundamental understanding and design of electrocatalytic systems.
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Affiliation(s)
- William R Lake
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Jinhui Meng
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jahan M Dawlaty
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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15
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Chang H, Lozier EH, Ma E, Geiger FM. Quantification of Stern Layer Water Molecules, Total Potentials, and Energy Densities at Fused Silica:Water Interfaces for Adsorbed Alkali Chlorides, CTAB, PFOA, and PFAS. J Phys Chem A 2023; 127:8404-8414. [PMID: 37775181 DOI: 10.1021/acs.jpca.3c04434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
We have employed amplitude- and phase-resolved second-harmonic generation spectroscopy to investigate ion-specific effects of monovalent cations at the fused silica:water interface maintained under acidic, neutral, and alkaline conditions. We find a negligible dependence of the total potential (as negative as -400 mV at pH 14), the second-order nonlinear susceptibility (as large as 1.5 × 10-21 m2 V-1 at pH 14), the number of Stern layer water molecules (1 × 1015 cm-2 at pH 5.8), and the energy associated with water alignment upon going from neutral to high pH (ca. -24 kJ mol-1 to -48 kJ mol-1 at pH 13 and 14, close to the cohesive energy of liquid water but smaller than that of ice) on chlorides of the alkali series (M+ = Li+, Na+, K+, Rb+, and Cs+). Attempts are presented to provide estimates for the molecular hyperpolarizability of the cations and anions in the Stern layer at high pH, which arrive at ca. 20-fold larger values for αtotal ions(2) = αM+(2) + αOH-(2) + αCl-(2) when compared to water's molecular hyperpolarizability estimate from theory and point to a sizable contribution of deprotonated silanol groups at high pH. In contrast to the alkali series, a pronounced dependence of the total potential and the second-order nonlinear susceptibility on monovalent cationic (cetrimonium bromide, CTAB) and anionic (perfluorooctanoic and perfluorooctanesulfonic acid, PFOA and PFOS) surfactants was quantifiable. Our findings are consistent with a low surface coverage of the alkali cations and a high surface coverage of the surfactants. Moreover, they underscore the important contribution of Stern layer water molecules to the total potential and second-order nonlinear susceptibility. Finally, they demonstrate the applicability of heterodyne-detected second-harmonic generation spectroscopy for identifying perfluorinated acids at mineral:water interfaces.
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Affiliation(s)
- HanByul Chang
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Emilie H Lozier
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Emily Ma
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Franz M Geiger
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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16
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Nguyen TTP, Raji F, Nguyen CV, Nguyen NN, Nguyen AV. Effects of Charged Surfactants on Interfacial Water Structure and Macroscopic Properties of the Air-Water Interface. Chemphyschem 2023:e202300062. [PMID: 37679310 DOI: 10.1002/cphc.202300062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/09/2023]
Abstract
Surfactants are used to control the macroscopic properties of the air-water interface. However, the link between the surfactant molecular structure and the macroscopic properties remains unclear. Using sum-frequency generation spectroscopy and molecular dynamics simulations, two ionic surfactants (dodecyl trimethylammonium bromide, DTAB, and sodium dodecyl sulphate, SDS) with the same carbon chain lengths and charge magnitude (but different signs) of head groups interact and reorient interfacial water molecules differently. DTAB forms a thicker but sparser interfacial layer than SDS. It is due to the deep penetration into the adsorption zone of Br- counterions compared to smaller Na+ ones, and also due to the flip-flop orientation of water molecules. SDS alters two distinctive interfacial water layers into a layer where H+ points to the air, forming strong hydrogen bonding with the sulphate headgroup. In contrast, only weaker dipole-dipole interactions with the DTAB headgroup are formed as they reorient water molecules with H+ point down to the aqueous phase. Hence, with more molecules adsorbed at the interface, SDS builds up a higher interfacial pressure than DTAB, producing lower surface tension and higher foam stability at a similar bulk concentration. Our findings offer improved knowledge for understanding various processes in the industry and nature.
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Affiliation(s)
- Thao T P Nguyen
- School of Chemical Engineering and UQ Node of the ARC Centre of Excellence for Enabling Eco-efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Foad Raji
- School of Chemical Engineering and UQ Node of the ARC Centre of Excellence for Enabling Eco-efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Cuong V Nguyen
- School of Chemical Engineering and UQ Node of the ARC Centre of Excellence for Enabling Eco-efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ngoc N Nguyen
- School of Chemical Engineering and UQ Node of the ARC Centre of Excellence for Enabling Eco-efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Anh V Nguyen
- School of Chemical Engineering and UQ Node of the ARC Centre of Excellence for Enabling Eco-efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
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17
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Bañuelos JL, Borguet E, Brown GE, Cygan RT, DeYoreo JJ, Dove PM, Gaigeot MP, Geiger FM, Gibbs JM, Grassian VH, Ilgen AG, Jun YS, Kabengi N, Katz L, Kubicki JD, Lützenkirchen J, Putnis CV, Remsing RC, Rosso KM, Rother G, Sulpizi M, Villalobos M, Zhang H. Oxide- and Silicate-Water Interfaces and Their Roles in Technology and the Environment. Chem Rev 2023; 123:6413-6544. [PMID: 37186959 DOI: 10.1021/acs.chemrev.2c00130] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Interfacial reactions drive all elemental cycling on Earth and play pivotal roles in human activities such as agriculture, water purification, energy production and storage, environmental contaminant remediation, and nuclear waste repository management. The onset of the 21st century marked the beginning of a more detailed understanding of mineral aqueous interfaces enabled by advances in techniques that use tunable high-flux focused ultrafast laser and X-ray sources to provide near-atomic measurement resolution, as well as by nanofabrication approaches that enable transmission electron microscopy in a liquid cell. This leap into atomic- and nanometer-scale measurements has uncovered scale-dependent phenomena whose reaction thermodynamics, kinetics, and pathways deviate from previous observations made on larger systems. A second key advance is new experimental evidence for what scientists hypothesized but could not test previously, namely, interfacial chemical reactions are frequently driven by "anomalies" or "non-idealities" such as defects, nanoconfinement, and other nontypical chemical structures. Third, progress in computational chemistry has yielded new insights that allow a move beyond simple schematics, leading to a molecular model of these complex interfaces. In combination with surface-sensitive measurements, we have gained knowledge of the interfacial structure and dynamics, including the underlying solid surface and the immediately adjacent water and aqueous ions, enabling a better definition of what constitutes the oxide- and silicate-water interfaces. This critical review discusses how science progresses from understanding ideal solid-water interfaces to more realistic systems, focusing on accomplishments in the last 20 years and identifying challenges and future opportunities for the community to address. We anticipate that the next 20 years will focus on understanding and predicting dynamic transient and reactive structures over greater spatial and temporal ranges as well as systems of greater structural and chemical complexity. Closer collaborations of theoretical and experimental experts across disciplines will continue to be critical to achieving this great aspiration.
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Affiliation(s)
- José Leobardo Bañuelos
- Department of Physics, The University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Eric Borguet
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Gordon E Brown
- Department of Earth and Planetary Sciences, The Stanford Doerr School of Sustainability, Stanford University, Stanford, California 94305, United States
| | - Randall T Cygan
- Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas 77843, United States
| | - James J DeYoreo
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Patricia M Dove
- Department of Geosciences, Department of Chemistry, Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24060, United States
| | - Marie-Pierre Gaigeot
- Université Paris-Saclay, Univ Evry, CNRS, LAMBE UMR8587, 91025 Evry-Courcouronnes, France
| | - Franz M Geiger
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Julianne M Gibbs
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2Canada
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Anastasia G Ilgen
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Young-Shin Jun
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Nadine Kabengi
- Department of Geosciences, Georgia State University, Atlanta, Georgia 30303, United States
| | - Lynn Katz
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - James D Kubicki
- Department of Earth, Environmental & Resource Sciences, The University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Johannes Lützenkirchen
- Karlsruher Institut für Technologie (KIT), Institut für Nukleare Entsorgung─INE, Eggenstein-Leopoldshafen 76344, Germany
| | - Christine V Putnis
- Institute for Mineralogy, University of Münster, Münster D-48149, Germany
| | - Richard C Remsing
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Kevin M Rosso
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Gernot Rother
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Marialore Sulpizi
- Department of Physics, Ruhr Universität Bochum, NB6, 65, 44780, Bochum, Germany
| | - Mario Villalobos
- Departamento de Ciencias Ambientales y del Suelo, LANGEM, Instituto De Geología, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Huichun Zhang
- Department of Civil and Environmental Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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18
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Wei F, Urashima SH, Nihonyanagi S, Tahara T. Elucidation of the pH-Dependent Electric Double Layer Structure at the Silica/Water Interface Using Heterodyne-Detected Vibrational Sum Frequency Generation Spectroscopy. J Am Chem Soc 2023; 145:8833-8846. [PMID: 37068781 PMCID: PMC10143621 DOI: 10.1021/jacs.2c11344] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Indexed: 04/19/2023]
Abstract
The silica/water interface is one of the most abundant charged interfaces in natural environments, and the elucidation of the water structure at the silica/water interface is essential. In the present study, we measured the interface-selective vibrational (χ(2)) spectra in the OH stretch region of the silica/water interface in a wide pH range of pH 2.0-12.0 while changing the salt concentration by heterodyne-detected vibrational sum-frequency generation spectroscopy. With the help of singular value decomposition analysis, it is shown that the imaginary part of the χ(2) (Imχ(2)) spectra can be decomposed into the spectra of the diffuse Gouy-Chapman layer (DL) and the compact Stern layer (SL), which enables us to quantitatively analyze the spectra of DL and SL separately. The salt-concentration dependence of the DL spectra at different pH values is analyzed using the modified Gouy-Chapman theory, and the pH-dependent surface charge density and the pKa value (4.8 ± 0.2) of the silica/water interface are evaluated. Furthermore, it is found that the pH-dependent change of the SL spectra is quantitatively explained by three spectral components that represent the three characteristic water species appearing in different pH regions in SL. The quantitative understanding obtained from the analysis of each spectral component in the Imχ(2) spectra provides a clear molecular-level picture of the electric double layer at the silica/water interface.
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Affiliation(s)
- Feng Wei
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Shu-hei Urashima
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Satoshi Nihonyanagi
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Ultrafast
Spectroscopy Research Team, RIKEN Center
for Advanced Photonics (RAP), Wako, Saitama 351-0198, Japan
| | - Tahei Tahara
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Ultrafast
Spectroscopy Research Team, RIKEN Center
for Advanced Photonics (RAP), Wako, Saitama 351-0198, Japan
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19
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Chu B, Marchioro A, Roke S. Size dependence of second-harmonic scattering from nanoparticles: Disentangling surface and electrostatic contributions. J Chem Phys 2023; 158:094711. [PMID: 36889968 DOI: 10.1063/5.0135157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
Polarimetric angle-resolved second-harmonic scattering (AR-SHS) is an all-optical tool enabling the study of unlabeled interfaces of nano-sized particles in an aqueous solution. As the second harmonic signal is modulated by interference between nonlinear contributions originating at the particle's surface and those originating in the bulk electrolyte solution due to the presence of a surface electrostatic field, the AR-SHS patterns give insight into the structure of the electrical double layer. The mathematical framework of AR-SHS has been previously established, in particular regarding changes in probing depth with ionic strength. However, other experimental factors may influence the AR-SHS patterns. Here, we calculate the size dependence of the surface and electrostatic geometric form factors for nonlinear scattering, together with their relative contribution to the AR-SHS patterns. We show that the electrostatic term is stronger in the forward scattering direction for smaller particle sizes, while the ratio of the electrostatic to surface terms decreases with increasing size. Besides this competing effect, the total AR-SHS signal intensity is also weighted by the particle's surface characteristics, given by the surface potential Φ0 and the second-order surface susceptibility χs,2 2. The weighting effect is experimentally demonstrated by comparing SiO2 particles of different sizes in NaCl and NaOH solutions of varying ionic strengths. For NaOH, the larger χs,2 2 values generated by deprotonation of surface silanol groups prevail over the electrostatic screening occurring at high ionic strengths; however, only for larger particle sizes. This study establishes a better connection between the AR-SHS patterns and surface properties and predicts trends for arbitrarily-sized particles.
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Affiliation(s)
- Bingxin Chu
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Arianna Marchioro
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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20
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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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21
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Rashwan M, Rehl B, Romaniuk N, Gibbs JM. Probing Silica-Kaolinite Interactions with Sum Frequency Generation Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:15984-15994. [PMID: 36519947 DOI: 10.1021/acs.langmuir.2c02414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Treating the oil sands tailings ponds is a major challenge because of the vast amounts of tailings and the need for a reliable treatment technique for releasing water and generating the highly consolidated material required for land reclamation. Treatment with chemicals such as lime (calcium (hydr)oxide) is a promising technology for tailings dewatering and consolidation, particularly at higher pH. Given that kaolinite and silica minerals are the main constituents of many oil sands, we have investigated the influence of lime and NaOH addition on the silica/aqueous kaolinite interface over the pH range 7.4-12.4 using vibrational sum frequency generation spectroscopy (SFG). With lime addition, at pH 12.0 and above we observe a complete disappearance of the vibrational features of the interfacial water molecules for planar silica in contact with an aqueous dispersion of kaolinite particles. A concurrent increase in the amount of adsorbed kaolinite on the silica surface at pH 12.0 and above is observed, shown in the increased intensity of the kaolinite SFG peak at 3694 cm-1. This suggests that the absence of water features in the SFG spectra is associated with conditions that facilitate dewatering. With NaOH addition, however, the interfacial water SF intensity is still significant even under highly alkaline conditions despite the increase in adsorbed kaolinite at high pH. To better understand the SFG observations and get a deeper insight into the chemistry of the silica/aqueous kaolinite interface, we measure the ζ-potential on the planar silica/aqueous interface and kaolinite aqueous dispersions under the same pH conditions with NaOH and lime addition.
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Affiliation(s)
- Mokhtar Rashwan
- Department of Chemistry, University of Alberta, Edmonton, AlbertaT6G 2G2, Canada
| | - Benjamin Rehl
- Department of Chemistry, University of Alberta, Edmonton, AlbertaT6G 2G2, Canada
| | - Nikolas Romaniuk
- Graymont Inc. 200-10991, Shelbridge Way, Richmond, British ColumbiaV6X 3C6, Canada
| | - Julianne M Gibbs
- Department of Chemistry, University of Alberta, Edmonton, AlbertaT6G 2G2, Canada
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22
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Kraka E, Quintano M, La Force HW, Antonio JJ, Freindorf M. The Local Vibrational Mode Theory and Its Place in the Vibrational Spectroscopy Arena. J Phys Chem A 2022; 126:8781-8798. [DOI: 10.1021/acs.jpca.2c05962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elfi Kraka
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Mateus Quintano
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Hunter W. La Force
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Juliana J. Antonio
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Marek Freindorf
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
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