1
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Clark JA, Robinson S, Espinoza EM, Bao D, Derr JB, Croft L, O'Mari O, Grover WH, Vullev VI. Poly(dimethylsiloxane) as a room-temperature solid solvent for photophysics and photochemistry. Phys Chem Chem Phys 2024; 26:8062-8076. [PMID: 38372740 DOI: 10.1039/d3cp05413f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Medium viscosity strongly affects the dynamics of solvated species and can drastically alter the deactivation pathways of their excited states. This study demonstrates the utility of poly(dimethylsiloxane) (PDMS) as a room-temperature solid-state medium for optical spectroscopy. As a thermoset elastic polymer, PDMS is transparent in the near ultraviolet, visible, and near infrared spectral regions. It is easy to mould into any shape, forming surfaces with a pronounced smoothness. While PDMS is broadly used for the fabrication of microfluidic devices, it swells in organic solvents, presenting severe limitations for the utility of such devices for applications employing non-aqueous fluids. Nevertheless, this swelling is reversible, which proves immensely beneficial for loading samples into the PDMS solid matrix. Transferring molecular-rotor dyes (used for staining prokaryotic cells and amyloid proteins) from non-viscous solvents into PDMS induces orders-of-magnitude enhancement of their fluorescence quantum yield and excited-state lifetimes, providing mechanistic insights about their deactivation pathways. These findings demonstrate the unexplored potential of PDMS as a solid solvent for optical applications.
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Affiliation(s)
- John A Clark
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Samantha Robinson
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Eli M Espinoza
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Duoduo Bao
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - James B Derr
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Luca Croft
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Omar O'Mari
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - William H Grover
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Valentine I Vullev
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
- Department of Chemistry, University of California, Riverside, CA 92521, USA
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
- Materials Science and Engineering Program, University of California, Riverside, CA 92521, USA
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2
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Yang YX, Yang XH, Huang ML, Wu LW, Liu Z, Cheng J, Huang YF. In Situ Spectroscopic Elucidation of the Electrochemical Potential Drop at Polyelectrolytes/Au Interfaces. J Phys Chem Lett 2024; 15:701-706. [PMID: 38214464 DOI: 10.1021/acs.jpclett.3c03111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Polyelectrolytes have been widely applied in electrochemical devices. Understanding the polyelectrolyte/electrode interfaces is pivotal for polyelectrolyte-based applications. Here, we measured the electrochemical potential drop and the local activity of the mobile ion of H+ or OH- at the polyelectrolytes/Au interfaces by in situ electrochemical surface-enhanced Raman spectroscopy and voltammetry in three-electrode cells. We found that the potential dependences of the electrochemical potential drop in polyelectrolytes were smaller than that in conventional electrolyte solutions. The interfacial activity of H+ or OH- was much lower than that of bulk polyelectrolytes. The potential-dependent molecular dynamics simulations showed that the mobility of ionomers of polyelectrolytes in an electrostatic field was limited by a polymer matrix. These results suggested a characteristically thicker compact layer in the electrical double layer of a polyelectrolyte/electrode interface due to the accumulation of mobile H+ or OH- with a thicker hydration layer and immobile ionomers.
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Affiliation(s)
- Yun-Xiao Yang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
| | - Xiao-Hui Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Mo-Li Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
| | - Li-Wen Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
| | - Zhi Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
- Center for Transformative Science, ShanghaiTech University, Shanghai 201210, P. R. China
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, P. R. China
| | - Yi-Fan Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
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3
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Ryan MJ, Yang N, Kwac K, Wilhelm KB, Chi BK, Weix DJ, Cho M, Zanni MT. The hydrogen-bonding dynamics of water to a nitrile-functionalized electrode is modulated by voltage according to ultrafast 2D IR spectroscopy. Proc Natl Acad Sci U S A 2023; 120:e2314998120. [PMID: 38127983 PMCID: PMC10756189 DOI: 10.1073/pnas.2314998120] [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: 08/29/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
We report the hydrogen-bonding dynamics of water to a nitrile-functionalized and plasmonic electrode surface as a function of applied voltage. The surface-enhanced two-dimensional infrared spectra exhibit hydrogen-bonded and non-hydrogen-bonded nitrile features in similar proportions, plus cross peaks between the two. Isotopic dilution experiments show that the cross peaks arise predominantly from chemical exchange between hydrogen-bonded and non-hydrogen-bonded nitriles. The chemical exchange rate depends upon voltage, with the hydrogen bond of the water to the nitriles breaking 2 to 3 times slower (>63 vs. 25 ps) under a positive as compared to a negative potential. Spectral diffusion created by hydrogen-bond fluctuations occurs on a ~1 ps timescale and is moderately potential-dependent. Timescales from molecular dynamics simulations agree qualitatively with the experiment and show that a negative voltage causes a small net displacement of water away from the surface. These results show that the voltage applied to an electrode can alter the timescales of solvent motion at its interface, which has implications for electrochemically driven reactions.
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Affiliation(s)
- Matthew J. Ryan
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Nan Yang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Kijeong Kwac
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul02841, Republic of Korea
| | - Kiera B. Wilhelm
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Benjamin K. Chi
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Daniel J. Weix
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul02841, Republic of Korea
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
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4
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Li K, You W, Wang W, Gong K, Liu Y, Wang L, Ge Q, Ruan X, Ao J, Ji M, Zhang L. Significantly Accelerated Photochemical Perfluorooctanoic Acid Decomposition at the Air-Water Interface of Microdroplets. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21448-21458. [PMID: 38047763 DOI: 10.1021/acs.est.3c05470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
The efficient elimination of per- and polyfluoroalkyl substances (PFASs) from the environment remains a huge challenge and requires advanced technologies. Herein, we demonstrate that perfluorooctanoic acid (PFOA) photochemical decomposition could be significantly accelerated by simply carrying out this process in microdroplets. The almost complete removal of 100 and 500 μg/L PFOA was observed after 20 min of irradiation in microdroplets, while this was achieved after about 2 h in the corresponding bulk phase counterpart. To better compare the defluorination ratio, 10 mg/L PFOA was used typically, and the defluorination rates in microdroplets were tens of times faster than that in the bulk phase reaction system. The high performances in actual water matrices, universality, and scale-up applicability were demonstrated as well. We revealed in-depth that the great acceleration is due to the abundance of the air-water interface in microdroplets, where the reactants concentration enrichment, ultrahigh interfacial electric field, and partial solvation effects synergistically promoted photoreactions responsible for PFOA decomposition, as evidenced by simulated Raman scattering microscopy imaging, vibrational Stark effect measurement, and DFT calculation. This study provides an effective approach and highlights the important roles of air-water interface of microdroplets in PFASs treatment.
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Affiliation(s)
- Kejian Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai 200433, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China
| | - Wenbo You
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Wei Wang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Kedong Gong
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Yangyang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Longqian Wang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Qiuyue Ge
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Xuejun Ruan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
| | - Jianpeng Ao
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, People's Republic of China
| | - Minbiao Ji
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, People's Republic of China
| | - Liwu Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, People's Republic of China
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Fudan University, Shanghai 200433, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China
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5
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Rusciano G, Capaccio A, Sasso A, Capo A, Almuzara CM, Staiano M, D’Auria S, Varriale A. A Surface-Enhanced Raman Spectroscopy-Based Biosensor for the Detection of Biological Macromolecules: The Case of the Lipopolysaccharide Endotoxin Molecules. Int J Mol Sci 2023; 24:12099. [PMID: 37569474 PMCID: PMC10419157 DOI: 10.3390/ijms241512099] [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: 07/09/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
The development of sensitive methods for the detection of endotoxin molecules, such as lipopolysaccharides (LPS), is essential for food safety and health control. Conventional analytical methods used for LPS detection are based on the pyrogen test, plating and culture-based methods, and the limulus amoebocyte lysate method (LAL). Alternatively, the development of reliable biosensors for LPS detection would be highly desirable to solve some critical issues, such as high cost and a long turnaround time. In this work, we present a label-free Surface-Enhanced Raman Spectroscopy (SERS)-based method for LPS detection in its free form. The proposed method combines the benefits of plasmonic enhancement with the selectivity provided by a specific anti-lipid A antibody (Ab). A high-enhancing nanostructured silver substrate was coated with Ab. The presence of LPS was quantitatively monitored by analyzing the changes in the Ab spectra obtained in the absence and presence of LPS. A limit of detection (LOD) and quantification (LOQ) of 12 ng/mL and 41 ng/mL were estimated, respectively. Importantly, the proposed technology could be easily expanded for the determination of other biological macromolecules.
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Affiliation(s)
- Giulia Rusciano
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (G.R.); (A.C.); (A.S.)
| | - Angela Capaccio
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (G.R.); (A.C.); (A.S.)
- Institute of Food Sciences (ISA), CNR, 83100 Avellino, Italy; (A.C.); (C.M.A.); (M.S.)
| | - Antonio Sasso
- Department of Physics “E. Pancini”, University of Naples “Federico II”, 80126 Naples, Italy; (G.R.); (A.C.); (A.S.)
| | - Alessandro Capo
- Institute of Food Sciences (ISA), CNR, 83100 Avellino, Italy; (A.C.); (C.M.A.); (M.S.)
| | | | - Maria Staiano
- Institute of Food Sciences (ISA), CNR, 83100 Avellino, Italy; (A.C.); (C.M.A.); (M.S.)
| | - Sabato D’Auria
- Department of Biology, Agriculture and Food Sciences, CNR, 00185 Rome, Italy
| | - Antonio Varriale
- Institute of Food Sciences, URT-CNR at Department of Biology, University of Naples “Federico II”, 80126 Naples, Italy;
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6
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Zhao J, Ma H, Liu Y, Xu B, Song L, Han X, Liu R, He C, Cheng Z, Zhao B. SERS-based biosensor for detection of f-PSA%: Implications for the diagnosis of prostate cancer. Talanta 2023; 261:124654. [PMID: 37196403 DOI: 10.1016/j.talanta.2023.124654] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/21/2023] [Accepted: 05/05/2023] [Indexed: 05/19/2023]
Abstract
In diagnosing prostate cancer and distinguishing it from other prostate diseases, the ratio of the concentration of free prostate-specific antigen (f-PSA) to total prostate-specific antigen (t-PSA), i.e., (f-PSA%) is more accurate than the concentration of t-PSA alone. Immunoassay based on surface-enhanced Raman scattering (SERS) frequency shift has been proven to be particularly suitable for detecting large biomolecules with high reproducibility. Along similar lines, the present study developed a SERS-based biosensor that simultaneously detects t-PSA and f-PSA. The 4-mercaptobenzoic acid (MBA) on the immunocapture substrate is coupled to the t-PSA antibody through the carboxyl group, and the combination of t-PSA induces the Raman frequency shifts of MBA. The immunocolloidal gold attached with f-PSA antibodies selectively capture the f-PSA that immobilized on the MBA-modified SERS substrates, allowing for f-PSA quantification according to the SERS intensities of the 5, 5'-Dithiobis (succinimidyl-2-nitrobenzoate) (DSNB) probe. The results show that f-PSA and t-PSA have good linear response in the concentration scale of 0.1-20 ng/mL, and 1-200 ng/mL, respectively. The biosensor combines Raman frequency shifts and intensities, which greatly simplifies traditional procedures for f-PSA% detection. All the results demonstrated the great potential of the proposed biosensor in highly reproducible and accurate diagnosis of prostate cancers.
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Affiliation(s)
- Junqi Zhao
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, PR China
| | - Hao Ma
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, PR China
| | - Yawen Liu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, PR China
| | - Baofeng Xu
- Department of Stroke Center, First Hospital of Jilin University, Changchun, China.
| | - Lina Song
- China-Japan Union Hospital of Jilin University, Changchun, 130033, PR China
| | - Xiaoxia Han
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, PR China
| | - Rui Liu
- China-Japan Union Hospital of Jilin University, Changchun, 130033, PR China
| | - Chengyan He
- China-Japan Union Hospital of Jilin University, Changchun, 130033, PR China
| | - Ziyi Cheng
- Key Laboratory of Emergency and Trauma, Ministry of Education, Hainan Medical University, Haikou, 571199, China
| | - Bing Zhao
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, PR China.
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7
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Choi Y, Jeon CS, Kim KB, Kim HJ, Pyun SH, Park YM. Quantitative detection of dopamine in human serum with surface-enhanced Raman scattering (SERS) of constrained vibrational mode. Talanta 2023; 260:124590. [PMID: 37146455 DOI: 10.1016/j.talanta.2023.124590] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/04/2023] [Accepted: 04/23/2023] [Indexed: 05/07/2023]
Abstract
Dopamine (DA) is a crucial neurotransmitter involved in the hormonal, nervous, and vascular systems being considered as an index to diagnose neurodegenerative diseases, including Parkinson's and Alzheimer's disease. Herein, we demonstrate the quantitative sensing of DA using the peak shift in surface-enhanced Raman scattering (SERS) of 4-mercaptophenylboronic acid (4-MPBA), resulting from the concentration of DA. To enable the signal enhancement of Raman scattering, Ag nanostructure was built with one-step gas-flow sputtering. 4-MPBA was then introduced using vapor-based deposition, acting as a reporter molecule for bonding with DA. The gradual peak-shift from 1075.6 cm-1 to 1084.7 cm-1 was observed with the increasing concentration of DA from 1 pM to 100nM. The numerical simulation revealed that DA bonding induced a constrained vibrational mode corresponding to 1084.7 cm-1 instead of a C-S-coupled C-ring in-plane bending mode of 4-MPBA corresponding to 1075.6 cm-1. Proposed SERS sensors depicted reliable DA detection in human serum and good selectivity against other analytes, including glucose, creatinine, and uric acid.
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Affiliation(s)
- Yongheum Choi
- Heat and Surface Technology R&D Department, Korea Institute of Industrial Technology (KITECH), Incheon, 21999, Republic of Korea
| | - Chang Su Jeon
- R&D Center, Speclipse Inc., Seongnam-si, Gyeonggi-do, 13461, Republic of Korea
| | - Kwang Bok Kim
- Digital Health Care R&D Department, Korea Institute of Industrial Technology (KITECH), Cheonan, 31056, Republic of Korea
| | - Hyun-Jong Kim
- Heat and Surface Technology R&D Department, Korea Institute of Industrial Technology (KITECH), Incheon, 21999, Republic of Korea
| | - Sung Hyun Pyun
- R&D Center, Speclipse Inc., Seongnam-si, Gyeonggi-do, 13461, Republic of Korea.
| | - Young Min Park
- Heat and Surface Technology R&D Department, Korea Institute of Industrial Technology (KITECH), Incheon, 21999, Republic of Korea.
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8
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Yang N, Ryan MJ, Son M, Mavrič A, Zanni MT. Voltage-Dependent FTIR and 2D Infrared Spectroscopies within the Electric Double Layer Using a Plasmonic and Conductive Electrode. J Phys Chem B 2023; 127:2083-2091. [PMID: 36821845 DOI: 10.1021/acs.jpcb.2c08431] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Strong electric fields exist between the electric double layer and charged surfaces. These fields impact molecular structures and chemistry at interfaces. We have developed a transparent electrode with infrared plasmonic enhancement sufficient to measure FTIR and two-dimensional infrared spectra at submonolayer coverages on the surface to which a voltage can be applied. Our device consists of an infrared transparent substrate, a 10-20 nm layer of conductive indium tin oxide (ITO), an electrically resistive layer of 3-5 nm Al2O3, and a 3 nm layer of nonconductive plasmonic gold. The materials and thicknesses are set to maximize the surface number density of the monolayer molecules, electrical conductivity, and plasmonic enhancement while minimizing background signals and avoiding Fano line shape distortions. The design was optimized by iteratively characterizing the material roughness and thickness with atomic force microscopy and electron microscopy and by monitoring the plasmon resonance enhancement with spectroscopy. The design is robust to repeated fabrication. This new electrode is tested on nitrile functional groups using a monolayer of 4-mercaptobenzonitrile as well as on CO and CC stretching modes using 4-mercaptobenzoic acid methyl ester. A voltage-dependent Stark shift is observed on both monolayers. We also observe that the transition dipole strength of the CN mode scales linearly with the applied voltage, providing a second way of measuring the surface electric field strength. We anticipate that this cell will enable many new voltage-dependent infrared experiments under applied voltages.
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Affiliation(s)
- Nan Yang
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Matthew J Ryan
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Minjung Son
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Andraž Mavrič
- University of Nova Gorica, Materials Research Laboratory, Vipavska 13, SI-5000 Nova Gorica, Slovenia
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
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9
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Datar A, Wright C, Matthews DA. Theoretical Investigation of the X-ray Stark Effect in Small Molecules. J Phys Chem A 2023; 127:1576-1587. [PMID: 36787229 DOI: 10.1021/acs.jpca.2c08311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We have studied the Stark effect in the soft x-ray region for various small molecules by calculating the field-dependent x-ray absorption spectra. This effect is explained in terms of the response of molecular orbitals (core and valence), the molecular dipole moment, and the molecular geometry to the applied electric field. A number of consistent trends are observed linking the computed shifts in absorption energies and intensities with specific features of the molecular electronic structure. We find that both the virtual molecular orbitals (valence and/or Rydberg) as well as the core orbitals contribute to observed trends in a complementary fashion. This initial study highlights the potential impact of x-ray Stark spectroscopy as a tool to study electronic structure and environmental perturbations at a submolecular scale.
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Affiliation(s)
- Avdhoot Datar
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Catherine Wright
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Devin A Matthews
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
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10
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Stone IB, Starr RL, Hoffmann N, Wang X, Evans AM, Nuckolls C, Lambert TH, Steigerwald ML, Berkelbach TC, Roy X, Venkataraman L. Interfacial electric fields catalyze Ullmann coupling reactions on gold surfaces. Chem Sci 2022; 13:10798-10805. [PMID: 36320717 PMCID: PMC9491086 DOI: 10.1039/d2sc03780g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/23/2022] [Indexed: 10/21/2023] Open
Abstract
The electric fields created at solid-liquid interfaces are important in heterogeneous catalysis. Here we describe the Ullmann coupling of aryl iodides on rough gold surfaces, which we monitor in situ using the scanning tunneling microscope-based break junction (STM-BJ) and ex situ using mass spectrometry and fluorescence spectroscopy. We find that this Ullmann coupling reaction occurs only on rough gold surfaces in polar solvents, the latter of which implicates interfacial electric fields. These experimental observations are supported by density functional theory calculations that elucidate the roles of surface roughness and local electric fields on the reaction. More broadly, this touchstone study offers a facile method to access and probe in real time an increasingly prominent yet incompletely understood mode of catalysis.
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Affiliation(s)
- Ilana B Stone
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Rachel L Starr
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Norah Hoffmann
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Xiao Wang
- Center for Computational Quantum Physics, Flatiron Institute New York New York 10010 USA
| | - Austin M Evans
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University Ithaca New York 14853 USA
| | | | - Timothy C Berkelbach
- Department of Chemistry, Columbia University New York New York 10027 USA
- Center for Computational Quantum Physics, Flatiron Institute New York New York 10010 USA
| | - Xavier Roy
- Department of Chemistry, Columbia University New York New York 10027 USA
| | - Latha Venkataraman
- Department of Chemistry, Columbia University New York New York 10027 USA
- Department of Applied Physics, Columbia University New York New York 10027 USA
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11
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Bhattacharyya D, Videla PE, Palasz JM, Tangen I, Meng J, Kubiak CP, Batista VS, Lian T. Sub-Nanometer Mapping of the Interfacial Electric Field Profile Using a Vibrational Stark Shift Ruler. J Am Chem Soc 2022; 144:14330-14338. [PMID: 35905473 DOI: 10.1021/jacs.2c05563] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The characterization of electrical double layers is important since the interfacial electric field and electrolyte environment directly affect the reaction mechanisms and catalytic rates of electrochemical processes. In this work, we introduce a spectroscopic method based on a Stark shift ruler that enables mapping the electric field strength across the electric double layer of electrode/electrolyte interfaces. We use the tungsten-pentacarbonyl(1,4-phenelenediisocyanide) complex attached to the gold surface as a molecular ruler. The carbonyl (CO) and isocyanide (NC) groups of the self-assembled monolayer (SAM) provide multiple vibrational reporters situated at different distances from the electrode. Measurements of Stark shifts under operando electrochemical conditions and direct comparisons to density functional theory (DFT) simulations reveal distance-dependent electric field strength from the electrode surface. This electric field profile can be described by the Gouy-Chapman-Stern model with Stern layer thickness of ∼4.5 Å, indicating substantial solvent and electrolyte penetration within the SAM. Significant electro-induction effect is observed on the W center that is ∼1.2 nm away from the surface despite rapid decay of the electric field (∼90%) within 1 nm. The applied methodology and reported findings should be particularly valuable for the characterization of a wide range of microenvironments surrounding molecular electrocatalysts at electrode interfaces and the positioning of electrocatalysts at specific distances from the electrode surface for optimal functionality.
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Affiliation(s)
- Dhritiman Bhattacharyya
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
| | - Pablo E Videla
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Joseph M Palasz
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, San Diego, California 92093, United States
| | - Isaac Tangen
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
| | - Jinhui Meng
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
| | - Clifford P Kubiak
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, San Diego, California 92093, United States
| | - Victor S Batista
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Tianquan Lian
- Department of Chemistry, Emory University, 1515 Dickey Drive Northeast, Atlanta, Georgia 30322, United States
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12
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Zhu Q, Wallentine SK, Deng GH, Rebstock JA, Baker LR. The Solvation-Induced Onsager Reaction Field Rather than the Double-Layer Field Controls CO 2 Reduction on Gold. JACS AU 2022; 2:472-482. [PMID: 35252996 PMCID: PMC8889607 DOI: 10.1021/jacsau.1c00512] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Indexed: 06/14/2023]
Abstract
The selectivity and activity of the carbon dioxide reduction (CO2R) reaction are sensitive functions of the electrolyte cation. By measuring the vibrational Stark shift of in situ-generated CO on Au in the presence of alkali cations, we quantify the total electric field present at catalytic active sites and deconvolute this field into contributions from (1) the electrochemical Stern layer and (2) the Onsager (or solvation-induced) reaction field. Contrary to recent theoretical reports, the CO2R kinetics does not depend on the Stern field but instead is closely correlated with the strength of the Onsager reaction field. These results show that in the presence of adsorbed (bent) CO2, the Onsager field greatly exceeds the Stern field and is primarily responsible for CO2 activation. Additional measurements of the cation-dependent water spectra using vibrational sum frequency generation spectroscopy show that interfacial solvation strongly influences the CO2R activity. These combined results confirm that the cation-dependent interfacial water structure and its associated electric field must be explicitly considered for accurate understanding of CO2R reaction kinetics.
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13
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Azimzadeh Sani M, Pavlopoulos NG, Pezzotti S, Serva A, Cignoni P, Linnemann J, Salanne M, Gaigeot M, Tschulik K. Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular‐Level Insights into the Electrical Double Layer. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202112679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mahnaz Azimzadeh Sani
- Analytical Chemistry II Faculty of Chemistry and Biochemistry Ruhr University Bochum 44801 Bochum Germany
| | | | - Simone Pezzotti
- Physical Chemistry II Faculty of Chemistry and Biochemistry Ruhr University Bochum 44780 Bochum Germany
| | - Alessandra Serva
- Sorbonne Université CNRS Physico-chimie des Electrolytes et Nanosystèmes Interfaciaux, PHENIX 75005 Paris France
| | - Paolo Cignoni
- Analytical Chemistry II Faculty of Chemistry and Biochemistry Ruhr University Bochum 44801 Bochum Germany
| | - Julia Linnemann
- Analytical Chemistry II Faculty of Chemistry and Biochemistry Ruhr University Bochum 44801 Bochum Germany
| | - Mathieu Salanne
- Sorbonne Université CNRS Physico-chimie des Electrolytes et Nanosystèmes Interfaciaux, PHENIX 75005 Paris France
- Institut Universitaire de France (IUF) 75231 Paris Cedex 05 France
| | | | - Kristina Tschulik
- Analytical Chemistry II Faculty of Chemistry and Biochemistry Ruhr University Bochum 44801 Bochum Germany
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14
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Stripping away ion hydration shells in electrical double-layer formation: Water networks matter. Proc Natl Acad Sci U S A 2021; 118:2108568118. [PMID: 34782461 PMCID: PMC8617503 DOI: 10.1073/pnas.2108568118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2021] [Indexed: 11/24/2022] Open
Abstract
For centuries the double layer at the solid/electrolyte interface has been a central concept in electrochemistry. Today, it is still crucial for virtually all renewable energy storage and conversion technologies. Here, the double-layer formation is probed by THz spectroscopy with ultrabright synchrotron light as a source. Our results capture the molecular details of double-layer formation at positively/negatively charged Au electrodes for an NaCl electrolyte. We reveal a contrasting response applying positive versus negative bias, which is dictated by the interfacial water network and rationalized by accompanying molecular dynamics simulations and electronic-structure calculations. While Na+ is directly attracted toward the negatively charged electrode, stripping of the Cl− hydration shell is observed only at larger potential values. The double layer at the solid/electrolyte interface is a key concept in electrochemistry. Here, we present an experimental study combined with simulations, which provides a molecular picture of the double-layer formation under applied voltage. By THz spectroscopy we are able to follow the stripping away of the cation/anion hydration shells for an NaCl electrolyte at the Au surface when decreasing/increasing the bias potential. While Na+ is attracted toward the electrode at the smallest applied negative potentials, stripping of the Cl− hydration shell is observed only at higher potential values. These phenomena are directly measured by THz spectroscopy with ultrabright synchrotron light as a source and rationalized by accompanying molecular dynamics simulations and electronic-structure calculations.
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15
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Azimzadeh Sani M, Pavlopoulos NG, Pezzotti S, Serva A, Cignoni P, Linnemann J, Salanne M, Gaigeot M, Tschulik K. Unexpectedly High Capacitance of the Metal Nanoparticle/Water Interface: Molecular-Level Insights into the Electrical Double Layer. Angew Chem Int Ed Engl 2021; 61:e202112679. [PMID: 34796598 PMCID: PMC9300121 DOI: 10.1002/anie.202112679] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Indexed: 11/29/2022]
Abstract
The electrical double‐layer plays a key role in important interfacial electrochemical processes from catalysis to energy storage and corrosion. Therefore, understanding its structure is crucial for the progress of sustainable technologies. We extract new physico‐chemical information on the capacitance and structure of the electrical double‐layer of platinum and gold nanoparticles at the molecular level, employing single nanoparticle electrochemistry. The charge storage ability of the solid/liquid interface is larger by one order‐of‐magnitude than predicted by the traditional mean‐field models of the double‐layer such as the Gouy–Chapman–Stern model. Performing molecular dynamics simulations, we investigate the possible relationship between the measured high capacitance and adsorption strength of the water adlayer formed at the metal surface. These insights may launch the active tuning of solid–solvent and solvent–solvent interactions as an innovative design strategy to transform energy technologies towards superior performance and sustainability.
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Affiliation(s)
- Mahnaz Azimzadeh Sani
- Analytical Chemistry II Faculty of Chemistry and BiochemistryRuhr University Bochum44801BochumGermany
| | | | - Simone Pezzotti
- Physical Chemistry II Faculty of Chemistry and BiochemistryRuhr University Bochum44780BochumGermany
| | - Alessandra Serva
- Sorbonne UniversitéCNRSPhysico-chimie des Electrolytes et Nanosystèmes Interfaciaux, PHENIX75005ParisFrance
| | - Paolo Cignoni
- Analytical Chemistry II Faculty of Chemistry and BiochemistryRuhr University Bochum44801BochumGermany
| | - Julia Linnemann
- Analytical Chemistry II Faculty of Chemistry and BiochemistryRuhr University Bochum44801BochumGermany
| | - Mathieu Salanne
- Sorbonne UniversitéCNRSPhysico-chimie des Electrolytes et Nanosystèmes Interfaciaux, PHENIX75005ParisFrance
- Institut Universitaire de France (IUF)75231Paris Cedex 05France
| | | | - Kristina Tschulik
- Analytical Chemistry II Faculty of Chemistry and BiochemistryRuhr University Bochum44801BochumGermany
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16
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Drexler CI, Cracchiolo OM, Myers RL, Okur HI, Serrano AL, Corcelli SA, Cremer PS. Local Electric Fields in Aqueous Electrolytes. J Phys Chem B 2021; 125:8484-8493. [PMID: 34313130 DOI: 10.1021/acs.jpcb.1c03257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vibrational Stark shifts were explored in aqueous solutions of organic molecules with carbonyl- and nitrile-containing constituents. In many cases, the vibrational resonances from these moieties shifted toward lower frequency as salt was introduced into solution. This is in contrast to the blue-shift that would be expected based upon Onsager's reaction field theory. Salts containing well-hydrated cations like Mg2+ or Li+ led to the most pronounced Stark shift for the carbonyl group, while poorly hydrated cations like Cs+ had the greatest impact on nitriles. Moreover, salts containing I- gave rise to larger Stark shifts than those containing Cl-. Molecular dynamics simulations indicated that cations and anions both accumulate around the probe in an ion- and probe-dependent manner. An electric field was generated by the ion pair, which pointed from the cation to the anion through the vibrational chromophore. This resulted from solvent-shared binding of the ions to the probes, consistent with their positions in the Hofmeister series. The "anti-Onsager" Stark shifts occur in both vibrational spectroscopy and fluorescence measurements.
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Affiliation(s)
| | - Olivia M Cracchiolo
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | | | - Halil I Okur
- Department of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - Arnaldo L Serrano
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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17
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Bhattacharyya D, Videla PE, Cattaneo M, Batista VS, Lian T, Kubiak CP. Vibrational Stark shift spectroscopy of catalysts under the influence of electric fields at electrode-solution interfaces. Chem Sci 2021; 12:10131-10149. [PMID: 34377403 PMCID: PMC8336477 DOI: 10.1039/d1sc01876k] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 07/13/2021] [Indexed: 11/24/2022] Open
Abstract
External control of chemical processes is a subject of widespread interest in chemical research, including control of electrocatalytic processes with significant promise in energy research. The electrochemical double-layer is the nanoscale region next to the electrode/electrolyte interface where chemical reactions typically occur. Understanding the effects of electric fields within the electrochemical double layer requires a combination of synthesis, electrochemistry, spectroscopy, and theory. In particular, vibrational sum frequency generation (VSFG) spectroscopy is a powerful technique to probe the response of molecular catalysts at the electrode interface under bias. Fundamental understanding can be obtained via synthetic tuning of the adsorbed molecular catalysts on the electrode surface and by combining experimental VSFG data with theoretical modelling of the Stark shift response. The resulting insights at the molecular level are particularly valuable for the development of new methodologies to control and characterize catalysts confined to electrode surfaces. This Perspective article is focused on how systematic modifications of molecules anchored to surfaces report information concerning the geometric, energetic, and electronic parameters of catalysts under bias attached to electrode surfaces. Heterogeneous electrocatalysis: characterization of interfacial electric field within the electrochemical double layer.![]()
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Affiliation(s)
- Dhritiman Bhattacharyya
- Department of Chemistry, Emory University 1515 Dickey Drive Northeast Atlanta Georgia 30322 USA
| | - Pablo E Videla
- Department of Chemistry and Energy Sciences Institute, Yale University 225 Prospect Street New Haven Connecticut 06520 USA
| | - Mauricio Cattaneo
- INQUINOA-UNT-CONICET, Facultad de Bioquímica, Química y Farmacia, Instituto de Química Física, Universidad Nacional de Tucumán Ayacucho 471 (4000) San Miguel de Tucumán Argentina
| | - Victor S Batista
- Department of Chemistry and Energy Sciences Institute, Yale University 225 Prospect Street New Haven Connecticut 06520 USA
| | - Tianquan Lian
- Department of Chemistry, Emory University 1515 Dickey Drive Northeast Atlanta Georgia 30322 USA
| | - Clifford P Kubiak
- Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Drive, MC 0358 La Jolla California 92093 USA
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18
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Delley MF, Nichols EM, Mayer JM. Interfacial Acid-Base Equilibria and Electric Fields Concurrently Probed by In Situ Surface-Enhanced Infrared Spectroscopy. J Am Chem Soc 2021; 143:10778-10792. [PMID: 34253024 DOI: 10.1021/jacs.1c05419] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding how applied potentials and electrolyte solution conditions affect interfacial proton (charge) transfers at electrode surfaces is critical for electrochemical technologies. Herein, we examine mixed self-assembled monolayers (SAMs) of 4-mercaptobenzoic acid (4-MBA) and 4-mercaptobenzonitrile (4-MBN) on gold using in situ surface-enhanced infrared absorption spectroscopy (SEIRAS). Measurements as a function of the applied potential, the electrolyte pD, and the electrolyte concentration determined both the relative surface populations of acidic and basic forms of 4-MBA, as well as the local electric fields at the SAM-solution interface by following the Stark shifts of 4-MBN. The effective acidity of the SAM varied with the applied potential, requiring a 600 mV change to move the pKa by one unit. Since this is ca. 10× the Nernstian value of 59 mV/pKa, ∼90% of the applied potential dropped across the SAM layer. This emphasizes the importance of distinguishing applied potentials from the potential experienced at the interface. We use the measured interfacial electric fields to estimate the experienced potential at the SAM edge. The SAM pKa showed a roughly Nernstian dependence on this estimated experienced potential. An analysis of the combined acid-base equilibria and Stark shifts reveals that the interfacial charge density has significant contributions from both SAM carboxylate headgroups and electrolyte components. Ion pairing and ion penetration into the SAM also influence the observed surface acidity. To our knowledge, this study is the first concurrent examination of both effective acidity and electric fields, and highlights the relevance of experienced potentials and specific ion effects at functionalized electrode surfaces.
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Affiliation(s)
- Murielle F Delley
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland.,Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Eva M Nichols
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.,Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - James M Mayer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
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19
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Noriega R. Measuring the Multiscale Dynamics, Structure, and Function of Biomolecules at Interfaces. J Phys Chem B 2021; 125:5667-5675. [PMID: 34042455 DOI: 10.1021/acs.jpcb.1c01546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The individual and collective structure and properties of biomolecules can change dramatically when they are localized at an interface. However, the small spatial extent of interfacial regions poses challenges to the detailed characterization of multiscale processes that dictate the structure and function of large biological units such as peptides, proteins, or nucleic acids. This Perspective surveys a broad set of tools that provide new opportunities to probe complex, dynamic interfaces across the vast range of temporal regimes that connect molecular-scale events to macroscopic observables. An emphasis is placed on the integration over multiple time scales, the use of complementary techniques, and the incorporation of external stimuli to control interfacial properties with spatial, temporal, and chemical specificity.
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Affiliation(s)
- Rodrigo Noriega
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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20
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Montenegro A, Dutta C, Mammetkuliev M, Shi H, Hou B, Bhattacharyya D, Zhao B, Cronin SB, Benderskii AV. Asymmetric response of interfacial water to applied electric fields. Nature 2021; 594:62-65. [PMID: 34079138 DOI: 10.1038/s41586-021-03504-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 03/29/2021] [Indexed: 11/09/2022]
Abstract
Our understanding of the dielectric response of interfacial water, which underlies the solvation properties and reaction rates at aqueous interfaces, relies on the linear response approximation: an external electric field induces a linearly proportional polarization. This implies antisymmetry with respect to the sign of the field. Atomistic simulations have suggested, however, that the polarization of interfacial water may deviate considerably from the linear response. Here we present an experimental study addressing this issue. We measured vibrational sum-frequency generation spectra of heavy water (D2O) near a monolayer graphene electrode, to study its response to an external electric field under controlled electrochemical conditions. The spectra of the OD stretch show a pronounced asymmetry for positive versus negative electrode charge. At negative charge below 5 × 1012 electrons per square centimetre, a peak of the non-hydrogen-bonded OD groups pointing towards the graphene surface is observed at a frequency of 2,700 per centimetre. At neutral or positive electrode potentials, this 'free-OD' peak disappears abruptly, and the spectra display broad peaks of hydrogen-bonded OD species (at 2,300-2,650 per centimetre). Miller's rule1 connects the vibrational sum-frequency generation response to the dielectric constant. The observed deviation from the linear response for electric fields of about ±3 × 108 volts per metre calls into question the validity of treating interfacial water as a simple dielectric medium.
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Affiliation(s)
- Angelo Montenegro
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Chayan Dutta
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | | | - Haotian Shi
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Bingya Hou
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
| | | | - Bofan Zhao
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Stephen B Cronin
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
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21
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Zhu W, Hutchison JA, Dong M, Li M. Frequency Shift Surface-Enhanced Raman Spectroscopy Sensing: An Ultrasensitive Multiplex Assay for Biomarkers in Human Health. ACS Sens 2021; 6:1704-1716. [PMID: 33939402 DOI: 10.1021/acssensors.1c00393] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The sensitive and selective detection of biomarkers for human health remains one of the grand challenges of the analytical sciences. Compared to established methods (colorimetric, (chemi) luminescent), surface-enhanced Raman spectroscopy (SERS) is an emerging alternative with enormous potential for ultrasensitive biological detection. Indeed even attomolar (10-18 M) detection limits are possible for SERS due to an orders-of-magnitude boosting of Raman signals at the surface of metallic nanostructures by surface plasmons. However, challenges remain for SERS assays of large biomolecules, as the largest enhancements require the biomarker to enter a "hot spot" nanogap between metal nanostructures. The frequency-shift SERS method has gained popularity in recent years as an alternative assay that overcomes this drawback. It measures frequency shifts in intense SERS peaks of a Raman reporter during binding events on biomolecules (protein coupling, DNA hybridization, etc.) driven by mechanical transduction, charge transfer, or local electric field effects. As such, it retains the excellent multiplexing capability of SERS, with multiple analytes being identifiable by a spectral fingerprint in a single read-out. Meanwhile, like refractive index surface plasmon resonance methods, frequency-shift SERS measures the shift of an intense signal rather than resolving a peak above noise, easing spectroscopic resolution requirements. SERS frequency-shift assays have proved particularly suitable for sensing large, highly charged biomolecules that alter hydrogen-bonding networks upon specific binding. Herein we discuss the frequency-shift SERS method and promising applications in (multiplex) biomarker sensing as well as extensions to ion and gas sensing and much more.
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Affiliation(s)
- Wenfeng Zhu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing 100049, China
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - James Andell Hutchison
- School of Chemistry, University of Melbourne, 30 Flemington Road, Parkville 3052, Victoria, Australia
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C 8000, Denmark
| | - Min Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, the Chinese Academy of Sciences, Beijing 100049, China
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22
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Li S, Zhao B, Aguirre A, Wang Y, Li R, Yang S, Aravind I, Cai Z, Chen R, Jensen L, Cronin SB. Monitoring Reaction Intermediates in Plasma-Driven SO 2, NO, and NO 2 Remediation Chemistry Using In Situ SERS Spectroscopy. Anal Chem 2021; 93:6421-6427. [PMID: 33855854 DOI: 10.1021/acs.analchem.0c05413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In situ surface-enhanced Raman scattering (SERS) spectroscopy is used to identify the key reaction intermediates during the plasma-based removal of NO and SO2 under dry and wet conditions on Ag nanoparticles. Density functional theory (DFT) calculations are used to confirm the experimental observations by calculating the vibrational modes of the surface-bound intermediate species. Here, we provide spectroscopic evidence that the wet plasma increases the SO2 and the NOx removal through the formation of highly reactive OH radicals, driving the reactions to H2SO4 and HNO3, respectively. We observed the formation of SO3 and SO4 species in the SO2 wet-plasma-driven remediation, while in the dry plasma, we only identified SO3 adsorbed on the Ag surface. During the removal of NO in the dry and wet plasma, both NO2 and NO3 species were observed on the Ag surface; however, the concentration of NO3 species was enhanced under wet-plasma conditions. By closing the loop between the experimental and DFT-calculated spectra, we identified not only the adsorbed species associated with each peak in the SERS spectra but also their orientation and adsorption site, providing a detailed atomistic picture of the chemical reaction pathway and surface interaction chemistry.
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Affiliation(s)
- Shujin Li
- Mork Family Department of Chemical Engineering and Materials Science and Daniel J. Epstein Department of Industrial & System Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Bofan Zhao
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Alejo Aguirre
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC), Universidad Nacional del Litoral, CONICET, Güemes 3450, S3000GLN Santa Fe, Argentina
| | - Yu Wang
- Mork Family Department of Chemical Engineering and Materials Science and Daniel J. Epstein Department of Industrial & System Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Ruoxi Li
- Mork Family Department of Chemical Engineering and Materials Science and Daniel J. Epstein Department of Industrial & System Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Sisi Yang
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
| | - Indu Aravind
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
| | - Zhi Cai
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Ran Chen
- Department of Chemistry Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Lasse Jensen
- Department of Chemistry Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Stephen B Cronin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States.,Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States
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23
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Yang TT, Patil RB, McKone JR, Saidi WA. Revisiting trends in the exchange current for hydrogen evolution. Catal Sci Technol 2021. [DOI: 10.1039/d1cy01170g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Nørskov and collaborators proposed a simple kinetic model to explain the volcano relation for hydrogen evolution reaction. Our new model decreases the discrepancy between calculated and experimental exchange current density values.
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Affiliation(s)
- Timothy T. Yang
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Rituja B. Patil
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - James R. McKone
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Wissam A. Saidi
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15260, USA
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24
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Khan MR, Singh H, Sharma S, Asetre Cimatu KL. Direct Observation of Adsorption Morphologies of Cationic Surfactants at the Gold Metal-Liquid Interface. J Phys Chem Lett 2020; 11:9901-9906. [PMID: 33170701 DOI: 10.1021/acs.jpclett.0c02517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Understanding interfacial phenomena is important in processes like corrosion, catalysis, and electrochemical reactions. Specifically, in corrosion inhibition, the assembly of adsorbed surfactants at metal-water interfaces in well-packed, ordered layers is desired. We provide direct evidence of the role of alkyl tails of surfactants in the formation of ordered adsorbed layers at metal-water interfaces. We have employed surface-specific sum frequency generation (SFG) spectroscopy to probe the in situ adsorption and self-assembly of cationic surfactants, alkyldimethylbenzyl ammonium bromides of tail lengths n = 4 (C4) and 12 (C12), without any applied potential or stimulus, at the gold-water interface. Our SFG measurements show that C12 Quat adsorbs as an ordered monolayer, whereas C4 Quat adsorbs in a disordered monolayer. All-atom molecular dynamics (MD) simulations of these surfactants corroborate with SFG results. These findings provide new insights on how hydrophobic interactions between alkyl tails of surfactants affect their self-assembly at metal-water interfaces.
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Affiliation(s)
- Md Rubel Khan
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, Ohio 45701-2979, United States
| | - Himanshu Singh
- Department of Chemical and Biomolecular Engineering, Ohio University, Athens, Ohio 45701, United States
| | - Sumit Sharma
- Department of Chemical and Biomolecular Engineering, Ohio University, Athens, Ohio 45701, United States
| | - Katherine Leslee Asetre Cimatu
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, Ohio 45701-2979, United States
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25
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Wallentine S, Bandaranayake S, Biswas S, Baker LR. Direct Observation of Carbon Dioxide Electroreduction on Gold: Site Blocking by the Stern Layer Controls CO 2 Adsorption Kinetics. J Phys Chem Lett 2020; 11:8307-8313. [PMID: 32946241 DOI: 10.1021/acs.jpclett.0c02628] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Directly observing active surface intermediates represents a major challenge in electrocatalysis, especially for CO2 electroreduction on Au. We use in-situ, plasmon-enhanced vibrational sum frequency generation spectroscopy, which has detection limits of <1% of a monolayer and can access the Au/electrolyte interface during active electrocatalysis in the absence of mass transport limitations. Measuring the potential-dependent surface coverage of atop CO confirms that the rate-determining step for this reaction is CO2 adsorption. An analysis of the interfacial electric field reveals the formation of a dense cation layer at the electrode surface, which is correlated to the onset of CO production. The Tafel slope increases in conjunction with the field saturation due to active site blocking by adsorbed cations. These findings show that CO2 reduction is extremely sensitive to the potential-dependent structure of the electrochemical double layer and provides direct observation of the interfacial processes that govern these kinetics.
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Affiliation(s)
- Spencer Wallentine
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Savini Bandaranayake
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Somnath Biswas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - L Robert Baker
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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26
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Wallentine S, Bandaranayake S, Biswas S, Baker LR. Plasmon-Resonant Vibrational Sum Frequency Generation of Electrochemical Interfaces: Direct Observation of Carbon Dioxide Electroreduction on Gold. J Phys Chem A 2020; 124:8057-8064. [DOI: 10.1021/acs.jpca.0c04268] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Spencer Wallentine
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Savini Bandaranayake
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Somnath Biswas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - L. Robert Baker
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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Goldsmith Z, Secor M, Hammes-Schiffer S. Inhomogeneity of Interfacial Electric Fields at Vibrational Probes on Electrode Surfaces. ACS CENTRAL SCIENCE 2020; 6:304-311. [PMID: 32123749 PMCID: PMC7047426 DOI: 10.1021/acscentsci.9b01297] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Indexed: 05/06/2023]
Abstract
Electric fields control chemical reactivity in a wide range of systems, including enzymes and electrochemical interfaces. Characterizing the electric fields at electrode-solution interfaces is critical for understanding heterogeneous catalysis and associated energy conversion processes. To address this challenge, recent experiments have probed the response of the nitrile stretching frequency of 4-mercaptobenzonitrile (4-MBN) attached to a gold electrode to changes in the solvent and applied electrode potential. Herein, this system is modeled with periodic density functional theory using a multilayer dielectric continuum treatment of the solvent and at constant applied potentials. The impact of the solvent dielectric constant and the applied electrode potential on the nitrile stretching frequency computed with a grid-based method is in qualitative agreement with the experimental data. In addition, the interfacial electrostatic potentials and electric fields as a function of applied potential were calculated directly with density functional theory. Substantial spatial inhomogeneity of the interfacial electric fields was observed, including oscillations in the region of the molecular probe attached to the electrode. These simulations highlight the microscopic inhomogeneity of the electric fields and the role of molecular polarizability at electrode-solution interfaces, thereby demonstrating the limitations of mean-field models and providing insights relevant to the interpretation of vibrational Stark effect experiments.
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28
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Sarkar S, Maitra A, Banerjee S, Thoi VS, Dawlaty JM. Electric Fields at Metal-Surfactant Interfaces: A Combined Vibrational Spectroscopy and Capacitance Study. J Phys Chem B 2020; 124:1311-1321. [PMID: 31985221 DOI: 10.1021/acs.jpcb.0c00560] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Surfactants modulate interfacial processes. In electrochemical CO2 reduction, cationic surfactants promote carbon product formation and suppress hydrogen evolution. The interfacial field produced by the surfactants affects the energetics of electrochemical intermediates, mandating their detailed understanding. We have used two complementary tools-vibrational Stark shift spectroscopy which probes interfacial fields at molecular length scales and electrochemical impedance spectroscopy (EIS) which probes the entire double layer-to study the electric fields at metal-surfactant interfaces. Using a nitrile as a probe, we found that at open-circuit potentials, cationic surfactants produce larger effective interfacial fields (∼-1.25 V/nm) when compared to anionic surfactants (∼0.4 V/nm). At a high bulk surfactant concentration, the surface field reaches a terminal value, suggesting the formation of a full layer, which is also supported by EIS. We propose an electrostatic model that explains these observations. Our results help in designing tailored surfactants for influencing electrochemical reactions via the interfacial field effect.
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Affiliation(s)
- Sohini Sarkar
- Department of Chemistry , University of Southern California , Los Angeles , California 90007 , United States
| | - Anwesha Maitra
- Department of Chemistry , University of Southern California , Los Angeles , California 90007 , United States
| | - Soumyodip Banerjee
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - V Sara Thoi
- Department of Chemistry , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Jahan M Dawlaty
- Department of Chemistry , University of Southern California , Los Angeles , California 90007 , United States
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29
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Shi H, Zhao B, Ma J, Bronson MJ, Cai Z, Chen J, Wang Y, Cronin M, Jensen L, Cronin SB. Measuring Local Electric Fields and Local Charge Densities at Electrode Surfaces Using Graphene-Enhanced Raman Spectroscopy (GERS)-Based Stark-Shifts. ACS APPLIED MATERIALS & INTERFACES 2019; 11:36252-36258. [PMID: 31498591 DOI: 10.1021/acsami.9b11892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report spectroscopic measurements of the local electric fields and local charge densities at electrode surfaces using graphene-enhanced Raman spectroscopy (GERS) based on the Stark-shifts of surface-bound molecules and the G band frequency shift in graphene. Here, monolayer graphene is used as the working electrode in a three-terminal potentiostat while Raman spectra are collected in situ under applied electrochemical potentials using a water immersion lens. First, a thin layer (1 Å) of copper(II) phthalocyanine (CuPc) molecules are deposited on monolayer graphene by thermal evaporation. GERS spectra are then taken in an aqueous solution as a function of the applied electrochemical potential. The shifts in vibrational frequencies of the graphene G band and CuPc are obtained simultaneously and correlated. The upshifts in the G band Raman mode are used to determine the free carrier density in the graphene sheet under these applied potentials. Of the three dominant peaks in the Raman spectra of CuPc (i.e., 1531, 1450, and 1340 cm-1), only the 1531 cm-1 peak exhibits Stark-shifts and can, thus, be used to report the local electric field strength at the electrode surface under electrochemical working conditions. Between applied electrochemical potentials from -0.8 V to 0.8 V vs NHE, the free carrier density in the graphene electrode spans a range from -4 × 1012 cm-2 to 2 × 1012 cm-2. Corresponding Stark-shifts in the CuPc peak around 1531 cm-1 are observed up to 1.0 cm-1 over a range of electric field strengths between -3.78 × 106 and 1.85 × 106 V/cm. Slightly larger Stark-shifts are observed in a 1 M KCl solution, compared to those observed in DI water, as expected based on the higher ion concentration of the electrolyte. Based on our data, we determine the Stark shift tuning rate to be 0.178 cm-1/ (106 V/cm), which is relatively small due to the planar nature of the CuPc molecule, which largely lies perpendicular to the electric field at this electrode surface. Computational simulations using density functional theory (DFT) predict similar Stark shifts and provide a detailed atomistic picture of the electric field-induced perturbations to the surface-bound CuPc molecules.
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Affiliation(s)
| | | | | | - Mark J Bronson
- Department of Chemistry , Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | | | | | | | | | - Lasse Jensen
- Department of Chemistry , Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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Biswas S, Wallentine S, Bandaranayake S, Baker LR. Controlling polaron formation at hematite surfaces by molecular functionalization probed by XUV reflection-absorption spectroscopy. J Chem Phys 2019; 151:104701. [DOI: 10.1063/1.5115163] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Somnath Biswas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Spencer Wallentine
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Savini Bandaranayake
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - L. Robert Baker
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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