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Adsorption behavior of uracil on external surface of MgO nanotubes: A new class of hybrid nano-bio materials. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Souda R, Aizawa T, Sugiyama N, Takeguchi M. Nucleation and growth of water ice on oxide surfaces: the influence of a precursor to water dissociation. Phys Chem Chem Phys 2020; 22:20515-20523. [PMID: 32966413 DOI: 10.1039/d0cp01897j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have investigated how nucleation and growth processes of ice are influenced by interfacial molecular interactions on some oxide surfaces, such as rutile TiO2(110), TiO2(100), MgO(100), and Al2O3(0001), based on the diffraction patterns of electrons transmitted through ice crystallites under the experimental configuration of reflection high energy electron diffraction (RHEED). The cubic ice Ic grows on the TiO2(110) surface with the epitaxial relationship of (110)Ic//(110)TiO2 and [001]Ic//[11[combining macron]0]TiO2. The epitaxial ice growth tends to be disturbed on the TiO2(110) surface under the presence of oxygen vacancies and adatoms. The result is not simply ascribable to small misfit values between TiO2 and ice Ic lattices (∼2%) because ice grains are formed randomly on TiO2(100). No template effects are identified during ice nucleation on the pristine MgO(100) and Al2O3(0001) surfaces either. The water molecules are chemisorbed weakly on these surfaces as a precursor to dissociation via the acid-base interaction. Such anchored water species act as an inhibitor of epitaxial ice growth because the orientation flexibility of physisorbed water during nucleation is hampered at the interface by the preferential formation of hydrogen bonds.
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Affiliation(s)
- Ryutaro Souda
- Transmission Electron Microscopy Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
| | - Takashi Aizawa
- Center for Functional Sensor & Actuator, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Naoyuki Sugiyama
- Transmission Electron Microscopy Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan. and Toray Research Center Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567, Japan
| | - Masaki Takeguchi
- Transmission Electron Microscopy Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
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Man IC, Soriga SG, Parvulescu V. Effect of Ca and Sr in MgO(100) on the activation of methanol and methyl acetate. Catal Today 2018. [DOI: 10.1016/j.cattod.2017.03.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Souda R. Interactions of methanol, ethanol, and 1-propanol with polar and nonpolar species in water at cryogenic temperatures. Phys Chem Chem Phys 2017; 19:2583-2590. [PMID: 28059424 DOI: 10.1039/c6cp07313a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methanol is known as a strong inhibitor of hydrate formation, but clathrate hydrates of ethanol and 1-propanol can be formed in the presence of help gases. To elucidate the hydrophilic and hydrophobic effects of alcohols, their interactions with simple solute species are investigated in glassy, liquid, and crystalline water using temperature-programmed desorption and time-of-flight secondary ion mass spectrometry. Nonpolar solute species embedded underneath amorphous solid water films are released during crystallization, but they tend to withstand water crystallization under the coexistence of methanol additives. The CO2 additives are released after crystallization along with methanol desorption. These results suggest strongly that nonpolar species that are hydrated (i.e., caged) associatively with methanol can withstand water crystallization. In contrast, ethanol and 1-propanol additives weakly affect the dehydration of nonpolar species during water crystallization, suggesting that the former tend to be caged separately from the latter. The hydrophilic vs. hydrophobic behavior of alcohols, which differs according to the aliphatic group length, also manifests itself in the different abilities of surface segregation of alcohols and their effects on the water crystallization kinetics.
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Affiliation(s)
- Ryutaro Souda
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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Spirkl FM, Kunz S, Schweinberger FF, Farnbacher AN, Schröter R, Heiz U. Improving metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy signals by means of a modified time-of-flight separation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:013114. [PMID: 22299936 DOI: 10.1063/1.3677648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The separation of ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) is usually performed by a time-of-flight (ToF) separation using pre-set ToF for both types of signal. In this work, we present a new, improved ex situ signal separation method for the separation of MIES and UPS for every single measurement. Signal separation issues due to changes of system parameters can be overcome by changing the ToF separation and therefore allowing for the application of a wider range of measuring conditions. The method also enables to identify and achieve separation of the two signals without any time consuming calibration and the use of any special material for the calibration. Furthermore, changes made to the discharge source are described that enable to operate an existing MIES/UPS source over a broader range of conditions. This allows for tuning of the yield of UV photons and metastable rare gas atoms leading to an improved signal to noise ratio. First results of this improved setup are well in agreement with spectra reported in literature and show increased resolution and higher signal intensities for both MIE and UP spectra compared to the previous, non-optimized setup.
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Affiliation(s)
- Florian M Spirkl
- Technische Universität München, Department Chemie, Garching b. München, Germany.
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Zhu J, Farmer JA, Ruzycki N, Xu L, Campbell CT, Henkelman G. Calcium Adsorption on MgO(100): Energetics, Structure, and Role of Defects. J Am Chem Soc 2008; 130:2314-22. [DOI: 10.1021/ja077865y] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Junfa Zhu
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
| | - Jason A. Farmer
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
| | - Nancy Ruzycki
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
| | - Lijun Xu
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
| | - Charles T. Campbell
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
| | - Graeme Henkelman
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712-0165
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Wang Y, Nguyen HN, Truong TN. Mechanisms of and Effect of Coadsorption on Water Dissociation on an Oxygen Vacancy of the MgO(100) Surface. Chemistry 2006; 12:5859-67. [PMID: 16729339 DOI: 10.1002/chem.200600027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The dissociation mechanism of a water molecule at an oxygen vacancy on the MgO(100) surface was studied by using the embedded cluster method at the DFT/B3 LYP level, while the energetic information was refined by using the IMOMO method at the CCSD level. We found that a water molecule initially adsorbs on one of the magnesium ions surrounding the vacancy site with a binding energy of 15.98 kcal mol(-1). It then can dissociate on the MgO(100) surface along two possible dissociation pathways. One pathway produces a hydroxyl group bonded to the original magnesium with a proton filling the vacancy via a transition state with a barrier of 4.67 kcal mol(-1) relative to the adsorbed water configuration. The other pathway yields two hydroxy groups; the hydroxy group originally belonging to the water molecule fills the vacancy, while the hydrogen atom binds with the surface oxygen to form the other hydroxy group. Hydrogen atoms of these hydroxy groups can recombine to form a hydrogen molecule and the surface is healed. Although the barrier (14.09 kcal mol(-1)) of the rate-controlling step of the latter pathway is higher than that of the former one, the energies of all of its stationary points are lower than that of the separated reactants (H(2)O+cluster). The effects of water coadsorption are modeled by placing an additional water molecule near the active center, which suggests that the more coadsorbed water molecules further stabilize the hydroxy species and prevent the hydrogen molecule formation through the latter pathway. The results support the photoemission spectral evidence of water dissociation on the defective MgO(100) surface at low water coverage.
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Affiliation(s)
- Yan Wang
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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Souda R. A temperature-programed time-of-flight secondary ion mass spectroscopy study of intermixing of amorphous ethanol and heavy-water films at 15–200 K. J Chem Phys 2005; 122:134711. [PMID: 15847493 DOI: 10.1063/1.1869372] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
On the basis of time-of-flight secondary ion mass spectrometry, the intermolecular interactions of amorphous ethanol and heavy-water films have been investigated in terms of the translational molecular diffusion, hydrogen-bond reorganization, and isotope scrambling. The morphology of the ethanol film (heavy-water film) changes at 120 K (165 K), and the isotope scrambling takes place between the ethanol and heavy-water molecules above 140 K. The intermixing of the layered binary films of ethanol and heavy water is induced at 120 K as a consequence of the increased mobility of the ethanol molecules but the mixing is incomplete at the molecular level. The complete mixing occurs above 140-150 K provided that the highly mobile water molecules emerge. It is concluded that the viscous liquid phase evolves above the conventional glass-transition temperatures (97 and 136 K for ethanol and heavy water, respectively), which is followed by the drastic morphological change (120 and 165 K) as a consequence of the increased fluidity of the films.
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Affiliation(s)
- Ryutaro Souda
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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Al-Abadleh HA, Al-Hosney HA, Grassian VH. Oxide and carbonate surfaces as environmental interfaces: the importance of water in surface composition and surface reactivity. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2004.09.059] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Rudberg J, Foster M. Adsorption of Methanol on the MgO(100) Surface: An Infrared Study at Room Temperature. J Phys Chem B 2004. [DOI: 10.1021/jp0468713] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jennifer Rudberg
- Department of Chemistry, University of Massachusetts-Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125
| | - Michelle Foster
- Department of Chemistry, University of Massachusetts-Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125
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Affiliation(s)
- Ryutaro Souda
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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Souda R, Kawanowa H, Kondo M, Gotoh Y. Hydrogen bonding between water and methanol studied by temperature-programmed time-of-flight secondary ion mass spectrometry. J Chem Phys 2003. [DOI: 10.1063/1.1602055] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Al-Abadleh HA, Grassian VH. Phase Transitions in Magnesium Nitrate Thin Films: A Transmission FT-IR Study of the Deliquescence and Efflorescence of Nitric Acid Reacted Magnesium Oxide Interfaces. J Phys Chem B 2003. [DOI: 10.1021/jp0275692] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hind A. Al-Abadleh
- Departments of Chemistry and Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242
| | - V. H. Grassian
- Departments of Chemistry and Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242
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