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Lins E, Andvaag IR, Read S, Rosendahl SM, Burgess IJ. Dual-Frequency Comb Spectroscopy Studies of Ionic Strength Effects in Time-Resolved ATR-SEIRAS. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Wang H, Abruña HD. New insights into methanol and formic acid electro-oxidation on Pt: Simultaneous DEMS and ATR-SEIRAS study under well-defined flow conditions and simulations of CO spectra. J Chem Phys 2022; 156:034703. [DOI: 10.1063/5.0071463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Hongsen Wang
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | - Héctor D. Abruña
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
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Thuy Thi Phan V, Andvaag IR, Boyle ND, Flaman GT, Unni B, Burgess IJ. Surface Sensitive Infrared Spectroelectrochemistry using Palladium Electrodeposited on ITO-Modified Internal Reflection Elements. Phys Chem Chem Phys 2022; 24:2925-2933. [DOI: 10.1039/d1cp05130j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Palladium nanoparticles have been electrodeposited on the surfaces of conductive indium tin oxide (ITO) modified silicon internal reflection elements. The resulting films are shown to be excellent platforms for attenuated...
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Kas R, Ayemoba O, Firet NJ, Middelkoop J, Smith WA, Cuesta A. In-Situ Infrared Spectroscopy Applied to the Study of the Electrocatalytic Reduction of CO 2 : Theory, Practice and Challenges. Chemphyschem 2019; 20:2904-2925. [PMID: 31441195 DOI: 10.1002/cphc.201900533] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 08/22/2019] [Indexed: 11/11/2022]
Abstract
The field of electrochemical CO2 conversion is undergoing significant growth in terms of the number of publications and worldwide research groups involved. Despite improvements of the catalytic performance, the complex reaction mechanisms and solution chemistry of CO2 have resulted in a considerable amount of discrepancies between theoretical and experimental studies. A clear identification of the reaction mechanism and the catalytic sites are of key importance in order to allow for a qualitative breakthrough and, from an experimental perspective, calls for the use of in-situ or operando spectroscopic techniques. In-situ infrared spectroscopy can provide information on the nature of intermediate species and products in real time and, in some cases, with relatively high time resolution. In this contribution, we review key theoretical aspects of infrared reflection spectroscopy, followed by considerations of practical implementation. Finally, recent applications to the electrocatalytic reduction of CO2 are reviewed, including challenges associated with the detection of reaction intermediates.
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Affiliation(s)
- Recep Kas
- Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Onagie Ayemoba
- School of Natural and Computing Sciences, University of Aberdeen, Aberdeen, AB24 3UE, Scotland, UK
| | - Nienke J Firet
- Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Joost Middelkoop
- Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Wilson A Smith
- Department of Chemical Engineering, Delft University of Technology, 2629 HZ, Delft, The Netherlands
| | - Angel Cuesta
- School of Natural and Computing Sciences, University of Aberdeen, Aberdeen, AB24 3UE, Scotland, UK
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Spalding A, Shanks K, Bennie J, Potter U, Ffrench-Constant R. Optical Modelling and Phylogenetic Analysis Provide Clues to the Likely Function of Corneal Nipple Arrays in Butterflies and Moths. INSECTS 2019; 10:insects10090262. [PMID: 31443396 PMCID: PMC6780202 DOI: 10.3390/insects10090262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/11/2019] [Accepted: 08/19/2019] [Indexed: 11/21/2022]
Abstract
The lenses in compound eyes of butterflies and moths contain an array of nipple-shaped protuberances, or corneal nipples. Previous work has suggested that these nipples increase light transmittance and reduce the eye glare of moths that are inactive during the day. This work builds on but goes further than earlier analyses suggesting a functional role for these structures including, for the first time, an explanation of why moths are attracted to UV light. Using a phylogenetic approach and 3D optical modelling, we show empirically that these arrays have been independently lost from different groups of moths and butterflies and vary within families. We find differences in the shape of nipples between nocturnal and diurnal species, and that anti-glow reflectance levels are different at different wave-lengths, a result thereby contradicting the currently accepted theory of eye glow for predator avoidance. We find that there is reduced reflectance, and hence greater photon absorption, at UV light, which is probably a reason why moths are attracted to UV. We note that the effective refractive index at the end of the nipples is very close to the refractive index of water, allowing almost all the species with nipples to see without distortion when the eye is partially or completely wet and providing the potential to keep eyes dry. These observations provide a functional explanation for these arrays. Of special interest is the finding that their repeated and independent loss across lepidopteran phylogeny is inconsistent with the explanation that they are being lost in the ‘higher’, more active butterflies.
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Affiliation(s)
- Adrian Spalding
- Centre for Ecology and Conservation, University of Exeter in Cornwall, Penryn Campus, Penryn TR10 9FE, UK.
- Spalding Associates (Environmental) Ltd., 10 Walsingham Place, Truro TR1 2RP, UK.
| | - Katie Shanks
- Environment and Sustainability Institute, University of Exeter Penryn Campus, Penryn TR10 9FE, UK
| | - Jon Bennie
- Centre for Geography and Environmental Science, Peter Lanyon Building, Penryn Campus, Treliever Road, Penryn, Cornwall, PenrynTR10 9FE, UK
| | - Ursula Potter
- Microscopy & Analysis Suite, Faculty of Science, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Richard Ffrench-Constant
- Centre for Ecology and Conservation, University of Exeter in Cornwall, Penryn Campus, Penryn TR10 9FE, UK
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McPherson IJ, Ash PA, Jones L, Varambhia A, Jacobs RMJ, Vincent KA. Electrochemical CO Oxidation at Platinum on Carbon Studied through Analysis of Anomalous in Situ IR Spectra. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:17176-17187. [PMID: 28845207 PMCID: PMC5563840 DOI: 10.1021/acs.jpcc.7b02166] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/21/2017] [Indexed: 05/29/2023]
Abstract
The oxidation of adsorbed CO is a key reaction in electrocatalysis. It has been studied extensively on both extended model surfaces and on nanoparticles; however, correlation between the two is far from simple. Molecular insight into the reaction is often provided using in situ IR spectroscopy; however, practical challenges mean in situ studies on nanoparticles have yet to provide the same level of detail as those on model surfaces. Here we use a new approach to in situ IR spectroscopy to study the mechanism of CO adlayer oxidation on a commercial carbon-supported Pt catalyst. We observe bipolar IR absorption bands but develop a simple model to enable fitting. Quantitative analysis of band behavior during the oxidation prepeak using the model agrees well with previous analysis based on conventional absorption bands. A second linear CO band is observed during the main oxidation region and is assigned to the distinct contribution of CO on step as opposed to terrace sites. Analysis of the step and terrace CO bands during oxidation shows that oxidation begins on the terraces of the nanoparticles before CO on steps is removed. Further correlation of this behavior with the current shows that step CO is only lost in the first of the two main oxidation peaks.
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Affiliation(s)
- Ian J. McPherson
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
| | - Philip A. Ash
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
| | - Lewys Jones
- Department
of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, U.K.
| | - Aakash Varambhia
- Department
of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, U.K.
| | - Robert M. J. Jacobs
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Kylie A. Vincent
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
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McPherson IJ, Ash PA, Jacobs RMJ, Vincent KA. Formate adsorption on Pt nanoparticles during formic acid electro-oxidation: insights from in situ infrared spectroscopy. Chem Commun (Camb) 2016; 52:12665-12668. [PMID: 27722249 DOI: 10.1039/c6cc05955d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Adsorbed formate is observed on a supported Pt nanoparticle for the first time during formic acid electro-oxidation. Bands assigned to OCO stretching and CH bending reveal some OCO but little CH bond weakening on adsorption compared to the free anion. The formate potential dependence is similar to polycrystalline electrodes while adsorbed CO persists up to +1.2 V, 0.5 V higher than on polycrystalline Pt.
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Affiliation(s)
- Ian J McPherson
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK.
| | - Philip A Ash
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK.
| | - Robert M J Jacobs
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Kylie A Vincent
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK.
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Wuttig A, Liu C, Peng Q, Yaguchi M, Hendon CH, Motobayashi K, Ye S, Osawa M, Surendranath Y. Tracking a Common Surface-Bound Intermediate during CO2-to-Fuels Catalysis. ACS CENTRAL SCIENCE 2016; 2:522-8. [PMID: 27610413 PMCID: PMC4999975 DOI: 10.1021/acscentsci.6b00155] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Indexed: 05/22/2023]
Abstract
Rational design of selective CO2-to-fuels electrocatalysts requires direct knowledge of the electrode surface structure during turnover. Metallic Cu is the most versatile CO2-to-fuels catalyst, capable of generating a wide array of value-added products, including methane, ethylene, and ethanol. All of these products are postulated to form via a common surface-bound CO intermediate. Therefore, the kinetics and thermodynamics of CO adsorption to Cu play a central role in determining fuel-formation selectivity and efficiency, highlighting the need for direct observation of CO surface binding equilibria under catalytic conditions. Here, we synthesize nanostructured Cu films adhered to IR-transparent Si prisms, and we find that these Cu surfaces enhance IR absorption of bound molecules. Using these films as electrodes, we examine Cu-catalyzed CO2 reduction in situ via IR spectroelectrochemistry. We observe that Cu surfaces bind electrogenerated CO, derived from CO2, beginning at -0.60 V vs RHE with increasing surface population at more negative potentials. Adsorbed CO is in dynamic equilibrium with dissolved (13)CO and exchanges rapidly under catalytic conditions. The CO adsorption profiles are pH independent, but adsorbed CO species undergo a reversible transformation on the surface in modestly alkaline electrolytes. These studies establish the potential, concentration, and pH dependencies of the CO surface population on Cu, which serve to maintain a pool of this vital intermediate primed for further reduction to higher order fuel products.
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Affiliation(s)
- Anna Wuttig
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
| | - Can Liu
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Qiling Peng
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Momo Yaguchi
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
- Graduate
School of Environmental Science, Hokkaido
University, Sapporo 060-0810, Japan
| | - Christopher H. Hendon
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
| | - Kenta Motobayashi
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Shen Ye
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Masatoshi Osawa
- Institute
for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Yogesh Surendranath
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
- E-mail:
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10
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Distortion of the amide-I and -II bands of an α-helical membrane protein, pharaonis halorhodopsin, depends on thickness of gold films utilized for surface-enhanced infrared absorption spectroscopy. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2012.11.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Iafisco M, Palazzo B, Ito T, Otsuka M, Senna M, Delgado-Lopez JM, Gomez-Morales J, Tampieri A, Prat M, Rimondini L. Preparation of core-shell poly(L-lactic) acid-nanocrystalline apatite hollow microspheres for bone repairing applications. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:2659-2669. [PMID: 22864504 DOI: 10.1007/s10856-012-4732-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 07/23/2012] [Indexed: 06/01/2023]
Abstract
In this paper, hybrid inorganic-organic core-shell hollow microspheres, made of poly(L-lactic acid) (PLLA) and biomimetic nano apatites (HA), were prepared from biodegradable and biocompatible substances, suitable for bone tissue applications. Preparation is started from Pickering emulsification, i.e., solid particle-stabilized emulsions in the absence of any molecular surfactant, where solid particles adsorbed to an oil-water interface. Stable oil-in-water emulsions were produced using biomimetic 20 nm sized HA nanocrystals as particulate emulsifier and a dichloromethane (CH(2)Cl(2)) solution of PLLA as oil phase. Hybrid hollow PLLA microspheres at three different HA nanocrystals surface coverage, ranging from 10 to 50 μm, were produced. The resulting materials were completely characterized with spectroscopic, calorimetric and microscopic techniques and the cytocompatibility was established by indirect contact tests with both fibroblasts and osteoblasts and direct contact with these latter. They displayed a high level of cytocompatibility and thus represent promising materials for drug delivery systems, cell carriers and scaffolds for regeneration of bone useful in the treatment of orthopaedic, maxillofacial and dental fields.
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Affiliation(s)
- Michele Iafisco
- Dipartimento di Scienze della Salute, Università del Piemonte Orientale, Novara, Italy.
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Li JT, Zhou ZY, Broadwell I, Sun SG. In-situ infrared spectroscopic studies of electrochemical energy conversion and storage. Acc Chem Res 2012; 45:485-94. [PMID: 22264174 DOI: 10.1021/ar200215t] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With their ability to convert chemical energy of fuels directly into electrical power or reversibly store electrical energy, systems such as fuel cells and lithium ion batteries are of great importance in managing energy use. In these electrochemical energy conversion and storage (EECS) systems, controlled electrochemical redox reactions generate or store the electrical energy, ideally under conditions that avoid or kinetically suppress side reactions. A comprehensive understanding of electrode reactions is critical for the exploration and optimization of electrode materials and is therefore the key issue for developing advanced EECS systems. Based on its fingerprint and surface selection rules, electrochemical in-situ FTIR spectroscopy (in-situ FTIRS) can provide real-time information about the chemical nature of adsorbates and solution species as well as intermediate/product species involved in the electrochemical reactions. These unique features make this technique well-suited for insitu studies of EECS. In this Account, we review the characterization of electrode materials and the investigation of interfacial reaction processes involved in EECS systems by using state-of-the-art in-situ FTIR reflection technologies, primarily with an external configuration. We introduce the application of in-situ FTIRS to EECS systems and describe relevant technologies including in-situ microscope FTIRS, in-situ time-resolved FTIRS, and the combinatorial FTIRS approach. We focus first on the in-situ steady-state and time-resolved FTIRS studies on the electrooxidation of small organic molecules. Next, we review the characterization of electrocatalysts through the IR properties of nanomaterials, such as abnormal IR effects (AIREs) and surface enhanced infrared absorption (SEIRA). Finally, we introduce the application of in-situ FTIRS to demonstrate the decomposition of electrolyte and (de)lithiation processes involved in lithium ion batteries. The body of work summarized here has substantially advanced the knowledge of electrode processes and represents the forefront in studies of EECS at the molecular level.
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Affiliation(s)
- Jun-Tao Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005, China
| | - Zhi-You Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005, China
| | - Ian Broadwell
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005, China
| | - Shi-Gang Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005, China
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Su Z, Climent V, Leitch J, Zamlynny V, Feliu JM, Lipkowski J. Quantitative SNIFTIRS studies of (bi)sulfate adsorption at the Pt(111) electrode surface. Phys Chem Chem Phys 2010; 12:15231-9. [PMID: 21046024 DOI: 10.1039/c0cp00860e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Subtractively normalized interfacial Fourier transform infrared reflection spectroscopy (SNIFTIRS) was applied to study (bi)sulfate adsorption on a Pt(111) surface in solutions of variable pH while maintaining a constant total bisulfate/sulfate ((bi)sulfate) concentration without the addition of an inert supporting electrolyte. The spectra were recorded for both the p- and s-polarizations of the IR radiation in order to differentiate between the IR bands of the (bi)sulfate species adsorbed on the electrode surface from those species located in the thin layer of electrolyte. The spectra recorded with p-polarized light consist of the IR bands from both the species adsorbed at the electrode surface and those present in the thin layer of electrolyte between the electrode surface and ZnSe window whereas the s-polarized spectra contain only the IR bands from the species located in the thin layer of electrolyte. A new procedure was developed to calculate the angle of incidence and thickness of the electrolyte between the Pt(111) electrode surface and the ZnSe IR transparent window. By combining these values with the knowledge of the optical constants for Pt, H(2)O and ZnSe, the mean square electric field strength (MSEFS) at the Pt(111) electrode surface and for thin layer of solution were accurately calculated. The spectra recorded using s-polarization were multiplied by the ratio of the average MSEFS for p- and s-polarizations and subtracted from the spectra recorded using p-polarization in order to remove the IR bands that arise from the species present within the thin layer cavity. In this manner, the resulting IR spectra contain only the IR bands for the anions adsorbed on the Pt(111) electrode surface. The spectra of adsorbed anions show little change with respect to the pH ranging from 1 to 5.6. This behavior indicates that the same species is predominantly adsorbed on the metal surface for this broad range of pH values and the results suggest that sulfate is the most likely candidate for this adsorbate.
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Affiliation(s)
- Zhangfei Su
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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