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An in-situ electrochemical IR investigation of solution CO electro-oxidation on a polycrystalline Au surface in an alkaline electrolyte: Identification of active reaction intermediates. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.04.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Structures and ultrafast dynamics of interfacial water assemblies on smooth hydrophobic surfaces. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.01.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Xu Y, Dibble CJ, Petrik NG, Smith RS, Kay BD, Kimmel GA. Complete Wetting of Pt(111) by Nanoscale Liquid Water Films. J Phys Chem Lett 2016; 7:541-547. [PMID: 26785059 DOI: 10.1021/acs.jpclett.5b02748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The melting and wetting of nanoscale crystalline ice films on Pt(111) that are transiently heated above the melting point in ultrahigh vacuum (UHV) using nanosecond laser pulses are studied with infrared reflection absorption spectroscopy and Kr temperature-programmed desorption. The as-grown crystalline ice films consist of nanoscale ice crystallites embedded in a hydrophobic water monolayer. Upon heating, these crystallites melt to form nanoscale droplets of liquid water. Rapid cooling after each pulse quenches the films, allowing them to be interrogated with UHV surface science techniques. With each successive heat pulse, these liquid drops spread across the surface until it is entirely covered with a multilayer water film. These results, which show that nanoscale water films completely wet Pt(111), are in contrast to molecular dynamics simulations predicting partial wetting of water drops on a hydrophobic water monolayer. The results provide valuable insights into the wetting characteristics of nanoscale water films on a clean, well-characterized, single-crystal surface.
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Affiliation(s)
- Yuntao Xu
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - Collin J Dibble
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - Nikolay G Petrik
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - R Scott Smith
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - Bruce D Kay
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
| | - Greg A Kimmel
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States
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Shorokhov D, Zewail AH. New Light on Molecular and Materials Complexity: 4D Electron Imaging. J Am Chem Soc 2009; 131:17998-8015. [DOI: 10.1021/ja907432p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dmitry Shorokhov
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, California 91125
| | - Ahmed H. Zewail
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory for Chemical Physics, California Institute of Technology, Pasadena, California 91125
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Ordered water structure at hydrophobic graphite interfaces observed by 4D, ultrafast electron crystallography. Proc Natl Acad Sci U S A 2009; 106:4122-6. [PMID: 19246378 DOI: 10.1073/pnas.0812409106] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interfacial water has unique properties in various functions. Here, using 4-dimensional (4D), ultrafast electron crystallography with atomic-scale spatial and temporal resolution, we report study of structure and dynamics of interfacial water assembly on a hydrophobic surface. Structurally, vertically stacked bilayers on highly oriented pyrolytic graphite surface were determined to be ordered, contrary to the expectation that the strong hydrogen bonding of water on hydrophobic surfaces would dominate with suppressed interfacial order. Because of its terrace morphology, graphite plays the role of a template. The dynamics is also surprising. After the excitation of graphite by an ultrafast infrared pulse, the interfacial ice structure undergoes nonequilibrium "phase transformation" identified in the hydrogen-bond network through the observation of structural isosbestic point. We provide the time scales involved, the nature of ice-graphite structural dynamics, and relevance to properties related to confined water.
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Frischkorn C, Wolf M. Femtochemistry at metal surfaces: nonadiabatic reaction dynamics. Chem Rev 2007; 106:4207-33. [PMID: 17031984 DOI: 10.1021/cr050161r] [Citation(s) in RCA: 274] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Christian Frischkorn
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany.
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Kubota J, Domen K. Study of the dynamics of surface molecules by time-resolved sum-frequency generation spectroscopy. Anal Bioanal Chem 2007; 388:17-27. [PMID: 17200849 DOI: 10.1007/s00216-006-0957-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 10/19/2006] [Accepted: 10/19/2006] [Indexed: 11/26/2022]
Abstract
Sum-frequency generation (SFG) is a nonlinear laser-spectroscopy technique suitable for analysis of adsorbed molecules. The sub-monolayer sensitivity of SFG spectroscopy enables vibrational spectra to be obtained with high specificity for a variety of molecules on a range of surfaces, including metals, oxides, and semiconductors. The use of ultra-short laser pulses on time-scales of picoseconds also makes time-resolved measurements possible; this can reveal ultrafast transient changes in molecular arrangements. This article reviews recent time-resolved SFG spectroscopy studies revealing site-hopping of adsorbed CO on metal surfaces and the dynamics of energy relaxation at water/metal interfaces.
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Affiliation(s)
- Jun Kubota
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuda, Midori-ku, Yokohama, 226-8503, Japan.
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Mizutani G, Koyama T, Tomizawa S, Sano H. Distinction between some saccharides in scattered optical sum frequency intensity images. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2005; 62:845-9. [PMID: 16303630 DOI: 10.1016/j.saa.2005.03.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Accepted: 03/15/2005] [Indexed: 05/05/2023]
Abstract
Using an optical sum frequency (SF) microscope with visible and infrared light pulses for excitation, we have attempted to distinguish among four saccharide species. The saccharides we studied were d-glucose, amylopectin, beta-cyclodextrin, and amylose. The wavelength of the infrared light was resonant to CH vibration. Amylose showed very weak sum frequency scattering for CH vibration among the four saccharides. As for the other three saccharides, we found a big difference in the sum frequency spectra of their CH stretching vibration near 2900 cm-1, when the incident visible and infrared light pulses were p- and s-polarized, respectively. Based on these facts, we have demonstrated a distinction between these three saccharides in the scattered SF intensity images.
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Affiliation(s)
- G Mizutani
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi-shi, Ishikawa 923-1292, Japan.
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Kubota J, Wada A, Domen K. Time-Resolved Sum-Frequency Generation Spectroscopy of Cyclohexane Adsorbed on Ni(111) under Ultrashort NIR Laser Pulse Irradiation. J Phys Chem B 2005; 109:20973-8. [PMID: 16853719 DOI: 10.1021/jp0536706] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The adsorption of cyclohexane on Ni(111) was studied by infrared-visible sum-frequency generation (SFG) spectroscopy with and without near-infrared (NIR) pump pulse irradiation. Two adsorption states of cyclohexane were found in the monolayer region, a low-coverage state showing SFG peaks at 2740, 2815, and 2865 cm(-1), and a high-coverage state showing peaks at 2740, 2815, and 2905 cm(-1). Both states coexisted on the saturated Ni(111) surface. The broad peak at 2740 cm(-1) was due to the softened CH stretching mode of the axial CH groups of cyclohexane that point toward the Ni(111) surface. The peaks at 2815 and 2865 (or 2905) cm(-1) were due to the symmetric and asymmetric stretching modes of CH(2) groups, respectively, that were free from the surface. Irradiation with NIR pulses caused a temporary jump in temperature at the Ni(111) surface and enhanced the intensity of the 2905 cm(-1) peak, but weakened the other peaks. This indicates that the temperature jump excited the cyclohexane molecules from the low-coverage state to the high-coverage state. The dynamics of the structural change observed in the adsorbed cyclohexane on NIR irradiation is discussed.
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Affiliation(s)
- Jun Kubota
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuda, Midori-ku, Yokohama 226-8503, Japan.
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Ruan CY, Lobastov VA, Vigliotti F, Chen S, Zewail AH. Ultrafast electron crystallography of interfacial water. Science 2004; 304:80-4. [PMID: 15064414 DOI: 10.1126/science.1094818] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report direct determination of the structures and dynamics of interfacial water on a hydrophilic surface with atomic-scale resolution using ultrafast electron crystallography. On the nanometer scale, we observed the coexistence of ordered surface water and crystallite-like ice structures, evident in the superposition of Bragg spots and Debye-Scherrer rings. The structures were determined to be dominantly cubic, but each undergoes different dynamics after the ultrafast substrate temperature jump. From changes in local bond distances (OH.O and O.O) with time, we elucidated the structural changes in the far-from-equilibrium regime at short times and near-equilibration at long times.
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Affiliation(s)
- Chong-Yu Ruan
- Laboratory for Molecular Sciences, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA
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