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Kowalska K, Skwarek E, Demianenko E, Paientko V. Composites with Immobilized Bioactive Spirulina on an Inorganic Substrate (Yellow Clay, Hydroxyapatite, SiO 2, TiO 2, ZnO). Chemphyschem 2024; 25:e202400251. [PMID: 38679578 DOI: 10.1002/cphc.202400251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
In order to improve the structural properties of clays and composites of powdered spirulina, clay, nanosilica, hydroxyapatite, TiO2 and ZnO were used as an additive for mechanical processing. As a result, composites with natural nanostructured materials (NNM) are prepared with improved structural properties and bioactivity. The mixtures based on NNM with crystalline kaolinite, clays and admixtures were processed in a knife mill. The materials were characterized using FTIR spectroscopy, nitrogen adsorption and desorption, SEM release of bioactive components (anthocyanin 0,004-0,07 mg/g; chlorophyll 20-29 mg/g), composite toxicity level (below 25%), particle size measurement and surface charge density, zeta potential. Adsorption enthalpies during the formation of an intermolecular complex during the interactions of an anthocyanin molecule with the appropriate component of the composite were also calculated. There are regularities in the characteristics depending on the type of NNM, particle morphology and textural features of solids. The morphological and structural properties of the components changed slighty in the blends because the processing was conducted under relatively low mechanical stress. The morphological, textural and structural characteristics of the composites as well as the transformation to a nanostructured state, assume great bioactive activity of the composites, interesting for practical applications in medicine and cosmetics.
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Affiliation(s)
- Klaudia Kowalska
- Department of Radiochemistry and Environmental Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, 3 Maria Curie-Skłodowska Sq., 20-031, Lublin, Poland
| | - Ewa Skwarek
- Department of Radiochemistry and Environmental Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, 3 Maria Curie-Skłodowska Sq., 20-031, Lublin, Poland
| | - Evgeny Demianenko
- Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164, Kyiv, Ukraine
| | - Victoria Paientko
- Department of Radiochemistry and Environmental Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, 3 Maria Curie-Skłodowska Sq., 20-031, Lublin, Poland
- Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164, Kyiv, Ukraine
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2
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Kobayashi T, Ikeda T, Nakayama A. Long-range proton and hydroxide ion transfer dynamics at the water/CeO 2 interface in the nanosecond regime: reactive molecular dynamics simulations and kinetic analysis. Chem Sci 2024; 15:6816-6832. [PMID: 38725504 PMCID: PMC11077578 DOI: 10.1039/d4sc01422g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/02/2024] [Indexed: 05/12/2024] Open
Abstract
The structural properties, dynamical behaviors, and ion transport phenomena at the interface between water and cerium oxide are investigated by reactive molecular dynamics (MD) simulations employing neural network potentials (NNPs). The NNPs are trained to reproduce density functional theory (DFT) results, and DFT-based MD (DFT-MD) simulations with enhanced sampling techniques and refinement schemes are employed to efficiently and systematically acquire training data that include diverse hydrogen-bonding configurations caused by proton hopping events. The water interfaces with two low-index surfaces of (111) and (110) are explored with these NNPs, and the structure and long-range proton and hydroxide ion transfer dynamics are examined with unprecedented system sizes and long simulation times. Various types of proton hopping events at the interface are categorized and analyzed in detail. Furthermore, in order to decipher the proton and hydroxide ion transport phenomena along the surface, a counting analysis based on the semi-Markov process is formulated and applied to the MD trajectories to obtain reaction rates by considering the transport as stochastic jump processes. Through this model, the coupling between hopping events, vibrational motions, and hydrogen bond networks at the interface are quantitatively examined, and the high activity and ion transport phenomena at the water/CeO2 interface are unequivocally revealed in the nanosecond regime.
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Affiliation(s)
- Taro Kobayashi
- Department of Chemical System Engineering, The University of Tokyo Tokyo 113-8656 Japan
| | - Tatsushi Ikeda
- Department of Chemical System Engineering, The University of Tokyo Tokyo 113-8656 Japan
| | - Akira Nakayama
- Department of Chemical System Engineering, The University of Tokyo Tokyo 113-8656 Japan
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3
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Ren G, Zhou M, Hu P, Chen JF, Wang H. Bubble-water/catalyst triphase interface microenvironment accelerates photocatalytic OER via optimizing semi-hydrophobic OH radical. Nat Commun 2024; 15:2346. [PMID: 38490989 PMCID: PMC10943107 DOI: 10.1038/s41467-024-46749-z] [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: 08/22/2023] [Accepted: 03/06/2024] [Indexed: 03/18/2024] Open
Abstract
Photocatalytic water splitting (PWS) as the holy grail reaction for solar-to-chemical energy conversion is challenged by sluggish oxygen evolution reaction (OER) at water/catalyst interface. Experimental evidence interestingly shows that temperature can significantly accelerate OER, but the atomic-level mechanism remains elusive in both experiment and theory. In contrast to the traditional Arrhenius-type temperature dependence, we quantitatively prove for the first time that the temperature-induced interface microenvironment variation, particularly the formation of bubble-water/TiO2(110) triphase interface, has a drastic influence on optimizing the OER kinetics. We demonstrate that liquid-vapor coexistence state creates a disordered and loose hydrogen-bond network while preserving the proton transfer channel, which greatly facilitates the formation of semi-hydrophobic •OH radical and O-O coupling, thereby accelerating OER. Furthermore, we propose that adding a hydrophobic substance onto TiO2(110) can manipulate the local microenvironment to enhance OER without additional thermal energy input. This result could open new possibilities for PWS catalyst design.
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Affiliation(s)
- Guanhua Ren
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China
| | - Min Zhou
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China
| | - Peijun Hu
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, UK
| | - Jian-Fu Chen
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China
| | - Haifeng Wang
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China.
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4
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Li Z, Chen L, Wu Z, Jia A, Shi S, Zhang H, Wang J, Liu Z, Shao WP, Yang F, Wu XP, Gong XQ, Huang W. Surface Oxygen Vacancy and Hydride Species on Ceria Are Detrimental to Acetylene Semihydrogenation Reaction. ACS Catal 2023. [DOI: 10.1021/acscatal.3c00248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Affiliation(s)
- Zhaorui Li
- Key Laboratory of Precise and Intelligent Chemistry, iChEM, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Lu Chen
- Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Zongfang Wu
- Hefei National Research Center for Physical Science at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei 230026, China
| | - AiPing Jia
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Shucheng Shi
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Hui Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Jia Wang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Zhi Liu
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Wei-Peng Shao
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Fan Yang
- School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Xin-Ping Wu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xue-Qing Gong
- Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Weixin Huang
- Key Laboratory of Precise and Intelligent Chemistry, iChEM, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
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5
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Chen H, Blatnik MA, Ritterhoff CL, Sokolović I, Mirabella F, Franceschi G, Riva M, Schmid M, Čechal J, Meyer B, Diebold U, Wagner M. Water Structures Reveal Local Hydrophobicity on the In 2O 3(111) Surface. ACS NANO 2022; 16:21163-21173. [PMID: 36449748 PMCID: PMC9798908 DOI: 10.1021/acsnano.2c09115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Clean oxide surfaces are generally hydrophilic. Water molecules anchor at undercoordinated surface metal atoms that act as Lewis acid sites, and they are stabilized by H bonds to undercoordinated surface oxygens. The large unit cell of In2O3(111) provides surface atoms in various configurations, which leads to chemical heterogeneity and a local deviation from this general rule. Experiments (TPD, XPS, nc-AFM) agree quantitatively with DFT calculations and show a series of distinct phases. The first three water molecules dissociate at one specific area of the unit cell and desorb above room temperature. The next three adsorb as molecules in the adjacent region. Three more water molecules rearrange this structure and an additional nine pile up above the OH groups. Despite offering undercoordinated In and O sites, the rest of the unit cell is unfavorable for adsorption and remains water-free. The first water layer thus shows ordering into nanoscopic 3D water clusters separated by hydrophobic pockets.
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Affiliation(s)
- Hao Chen
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
- State
Key Laboratory of Catalysis, Dalian Institute
of Chemical Physics, Chinese Academy of Sciences, Dalian116023, China
- University
of the Chinese Academy of Sciences, Beijing100049, China
| | - Matthias A. Blatnik
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
- Central
European Institute of Technology (CEITEC), Brno University of Technology, 61200Brno, Czech
Republic
| | - Christian L. Ritterhoff
- Interdisciplinary
Center for Molecular Materials (ICMM) and Computer Chemistry Center
(CCC), Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), 91052Erlangen, Germany
| | - Igor Sokolović
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
| | | | | | - Michele Riva
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
| | - Michael Schmid
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
| | - Jan Čechal
- Central
European Institute of Technology (CEITEC), Brno University of Technology, 61200Brno, Czech
Republic
| | - Bernd Meyer
- Interdisciplinary
Center for Molecular Materials (ICMM) and Computer Chemistry Center
(CCC), Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), 91052Erlangen, Germany
| | - Ulrike Diebold
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
| | - Margareta Wagner
- Institute
of Applied Physics, TU Wien, 1040Vienna, Austria
- Central
European Institute of Technology (CEITEC), Brno University of Technology, 61200Brno, Czech
Republic
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6
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Sun Y, Zhang J, Zhou D, Wang D, Wang Q, Tan X, Shao X. Tailoring the Dispersion of Metals on ZnO with Preadsorbed Water. J Phys Chem Lett 2022; 13:10207-10215. [PMID: 36287143 DOI: 10.1021/acs.jpclett.2c03031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The dispersity of metal particles over oxide surfaces is generally critical for the applications of the metal/oxide hybridized systems. In this work, we have experimentally investigated the hydration effect of preadsorbed water species over the Cu and Pd particles deposited on the ZnO(10-10) surface. Using scanning tunneling microscopy (STM), we clearly saw that both Cu and Pd grow as three-dimensional particles on the clean ZnO(10-10) surface but disperse into single atoms and few-atom clusters on the water-covered surfaces. Moreover, X-ray photoelectron spectroscopy (XPS) measurements revealed that Cu is readily oxidized by interacting with the molecular water while Pd tends to bind the surface hydroxyls and keep neutral status. Our work has demonstrated the effective role of the surface water in tuning the morphologies as well as electronic states of the supported metals, which may bring new insights to a number of important surface processes with water in presence.
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Affiliation(s)
- Yuniu Sun
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jiefu Zhang
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dandan Zhou
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dan Wang
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qingqing Wang
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaolin Tan
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiang Shao
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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7
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Li X, Cheng X, Zhang H. Modeling of laser-pulse induced small water cluster-(H 2O) N ( N = 1-10) decomposition on suitable metal cluster catalysts. Phys Chem Chem Phys 2022; 24:17623-17631. [PMID: 35833491 DOI: 10.1039/d2cp02387c] [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
Understanding the microscopic mechanisms of electronic excitation in water clusters is a very important and challenging problem in a series of solar energy applications, such as solar water evaporation, photolysis, etc. Here we employ real time-time-dependent density functional theory (RT-TDDFT) and Ehrenfest dynamics to investigate the photodissociation dynamic process of (H2O)N=1-10 clusters and photoinduced charge transfer in them. The research presented here confirms that the plane tetramer, (H2O)4, is the most difficult one to be dissociated under laser irradiation in the ten clusters for its high (S4) symmetry; the overall order of the ease of decomposition is as follows: (H2O)6-p > (H2O)8 > (H2O)6-c > (H2O)7 > (H2O)10 > (H2O)1 > (H2O)3 > (H2O)2 > (H2O)9 > (H2O)5 > (H2O)4. Plasmon catalyst-induced water splitting is a promising and feasible way to efficiently convert solar to chemical energy via reducing the laser amplitude threshold significantly; and among the Ag6, Au6, Cu6, Al6 chains and several Cu6 clusters with Oh symmetry, the Cu6 chain seems to be the most cost-effective one. This article aims at unraveling the fundamental mechanisms and providing valuable physical insights into the behavior of water splitting to pave the way for the theoretical and experimental design of the photolysis process.
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Affiliation(s)
- Xiaojuan Li
- College of Physics, Sichuan University, Chengdu 610065, China.
| | - Xinlu Cheng
- Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610065, China
| | - Hong Zhang
- College of Physics, Sichuan University, Chengdu 610065, China. .,Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610065, China
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8
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Sun Y, Shi H, Yuan H, Li Z, Zhang J, Zhou D, Li Z, Shao X. Unveiling the Atomic Structure and Growth Dynamics of One-Dimensional Water on ZnO(10-10). J Phys Chem Lett 2022; 13:1554-1562. [PMID: 35137584 DOI: 10.1021/acs.jpclett.1c04203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The adsorption and organization state of water on the metal oxide surface is of critical importance for wide fields where interface chemistry dominates. On the technically important ZnO(10-10) surface, we found water assembles into an one-dimensional (1D) chain structure at submonolayer coverage instead of the well-known half-dissociated two-dimensional (2D) island. With a combination of high resolution scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we clearly distinguished the single and double water chains, which are composed of dissociated monomers and half-dissociated dimers, respectively. Moreover, we unambiguously determined that single water molecules dissociate spontaneously before agglomerating into ordered phase, which is contrary to the proposition of previous studies. These results have deepened our understandings of the adsorbed water species on the ZnO surface, which may bring new insights into the mechanisms of water-stimulated surface reactions.
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Affiliation(s)
- Yuniu Sun
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Hong Shi
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Hao Yuan
- HFNL, University of Science and Technology of China, Hefei 230026, China
| | - Zhe Li
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Jiefu Zhang
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Dandan Zhou
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
| | - Zhenyu Li
- HFNL, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
| | - Xiang Shao
- Department of Chemical Physics, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
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9
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Biliškov N. Infrared spectroscopic monitoring of solid-state processes. Phys Chem Chem Phys 2022; 24:19073-19120. [DOI: 10.1039/d2cp01458k] [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
We put a spotlight on IR spectroscopic investigations in materials science by providing a critical insight into the state of the art, covering both fundamental aspects, examples of its utilisation, and current challenges and perspectives focusing on the solid state.
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Affiliation(s)
- Nikola Biliškov
- Rudjer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada
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10
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Comparative Study of Cold Sintering Process and Autoclave Thermo-Vapor Treatment on a ZnO Sample. CRYSTALS 2021. [DOI: 10.3390/cryst11010071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Analysis of scanning electron microscopy images was used to study the changes in the crystal size distribution of ZnO, which occurred during its processing in an aqueous medium at 220–255 °C and an equilibrium vapor pressure in an autoclave. The results were compared with those of ZnO placed in a die for treatment under similar conditions supplemented with mechanical pressure application in the cold sintering process. In both cases, ZnO was treated in the presence of an activating additive: either zinc acetate or ammonium chloride. During autoclaving, a powder consisting of fine ZnO monocrystals was obtained, while the cold sintering process led to ceramics formation. Under vapor pressure and mechanical pressure, the aqueous medium affected ZnO transformation by the same mechanism of solid-phase mobility activation due to the additives’ influence. The higher the content of additives in the medium, and the higher the mechanical pressure, the more pronounced activating effect was observed. Mass transfer during the cold sintering process occurred mainly by the coalescence of crystals, while without mechanical pressure, the predominance of surface spreading was revealed. In the initial ZnO powder, the average crystal size was 0.193 μm. It grew up to 0.316–0.386 μm in a fine-crystalline powder formed in the autoclave and to an average grain size of 0.244–0.799 μm in the ceramics, which relative density reached 0.82–0.96. A scheme explaining the influence of an aqueous medium on the solid-phase mobility of ZnO structure was proposed. It was found that the addition of 7.6 mol% ammonium chloride to the reaction medium causes the processes of compaction and grain growth similar to those observed in ZnO Cold Sintering Process with the addition of 0.925 mol% zinc acetate.
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11
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Yu X, Roth JP, Wang J, Sauter E, Nefedov A, Heißler S, Pacchioni G, Wang Y, Wöll C. Chemical Reactivity of Supported ZnO Clusters: Undercoordinated Zinc and Oxygen Atoms as Active Sites. Chemphyschem 2020; 21:2553-2564. [PMID: 33118300 PMCID: PMC7756222 DOI: 10.1002/cphc.202000747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/21/2020] [Indexed: 11/06/2022]
Abstract
The growth of ZnO clusters supported by ZnO-bilayers on Ag(111) and the interaction of these oxide nanostructures with water have been studied by a multi-technique approach combining temperature-dependent infrared reflection absorption spectroscopy (IRRAS), grazing-emission X-ray photoelectron spectroscopy, and density functional theory calculations. Our results reveal that the ZnO bilayers exhibiting graphite-like structure are chemically inactive for water dissociation, whereas small ZnO clusters formed on top of these well-defined, yet chemically passive supports show extremely high reactivity - water is dissociated without an apparent activation barrier. Systematic isotopic substitution experiments using H2 16 O/D2 16 O/D2 18 O allow identification of various types of acidic hydroxyl groups. We demonstrate that a reliable characterization of these OH-species is possible via co-adsorption of CO, which leads to a red shift of the OD frequency due to the weak interaction via hydrogen bonding. The theoretical results provide atomic-level insight into the surface structure and chemical activity of the supported ZnO clusters and allow identification of the presence of under-coordinated Zn and O atoms at the edges and corners of the ZnO clusters as the active sites for H2 O dissociation.
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Affiliation(s)
- Xiaojuan Yu
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Jannik P. Roth
- Dipartimento di Scienza dei MaterialiUniversità Milano-BicoccaVia R. Cozzi 5520125MilanoItaly
| | - Junjun Wang
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Eric Sauter
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Alexei Nefedov
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Stefan Heißler
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei MaterialiUniversità Milano-BicoccaVia R. Cozzi 5520125MilanoItaly
| | - Yuemin Wang
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
| | - Christof Wöll
- Institute of Functional InterfacesKarlsruhe Institute of TechnologyEggenstein-Leopoldshafen76344Germany
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12
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Deskins NA, Kimmel GA, Petrik NG. Observation of Molecular Hydrogen Produced from Bridging Hydroxyls on Anatase TiO 2(101). J Phys Chem Lett 2020; 11:9289-9297. [PMID: 33090788 DOI: 10.1021/acs.jpclett.0c02735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Anatase TiO2 is used extensively in a wide range of catalytic and photocatalytic processes and is a promising catalyst for hydrogen production. Here, we show that molecular hydrogen was produced from bridging hydroxyls (HOb) on the (101) surface of single-crystal anatase (TiO2(101)). This stands in contrast to rutile TiO2(110), where HOb pairs react to form H2O. Electron bombardment at 30 K produced bridging oxygen vacancies in the surface. Deuterated bridging hydroxyls (DOb) were subsequently formed via dissociation of adsorbed D2O and confirmed by infrared reflection-absorption spectroscopy. During temperature-programmed desorption (TPD) spectroscopy, D2 desorption was observed at 520 K. Density functional theory calculations show that both H2 and H2O production from HOb are endothermic at 0 K on TiO2(101), but H2 (H2O) desorption is entropically driven above 230 K (800 K). The calculated activation barrier for H2 desorption is 1.40 eV, which is similar to the desorption energy obtained from analysis of the D2 TPD spectra. The H2 desorption likely proceeds in two steps: H atom diffusion on the surface and then recombination.
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Affiliation(s)
- N Aaron Deskins
- Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609, United States
| | - Greg A Kimmel
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Nikolay G Petrik
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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13
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Gerrard N, Mistry K, Darling GR, Hodgson A. Formation of Linear Water Chains on Ni(110). J Phys Chem Lett 2020; 11:2121-2126. [PMID: 32109072 DOI: 10.1021/acs.jpclett.0c00407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Materials that bind strongly to water structure the contact layer, modifying its chemical and physical properties in a manner that depends on the symmetry and reactivity of the surface. Although detailed models have been developed for several inert surfaces, much less is known about reactive surfaces, particularly those with a symmetry different from that of ice. Here we investigate water adsorption on a rectangular surface, Ni(110), an active re-forming catalyst that interacts strongly with water. Instead of forming a network of H-bonded cyclic rings, water forms flat 1D water chains, leaving half the Ni atoms exposed. Second layer water also follows the surface symmetry, forming chains of alternating pentamer and heptamer rings in preference to an extended 2D structure. This behavior is different from that found on other surfaces studied previously and is driven by the short lattice spacing of the solid and the strength of the Ni-water bond.
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Affiliation(s)
- Nikki Gerrard
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
| | - Kallum Mistry
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
| | - George R Darling
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
| | - Andrew Hodgson
- Surface Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
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Yu X, Schwarz P, Nefedov A, Meyer B, Wang Y, Wöll C. Structural Evolution of Water on ZnO(10 1 ‾ 0): From Isolated Monomers via Anisotropic H-Bonded 2D and 3D Structures to Isotropic Multilayers. Angew Chem Int Ed Engl 2019; 58:17751-17757. [PMID: 31637780 PMCID: PMC6899783 DOI: 10.1002/anie.201910191] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Indexed: 11/07/2022]
Abstract
The surface chemistry of water on zinc oxides is an important topic in catalysis and photocatalysis. Interaction of D2O with anisotropic ZnO(101‾
0) surfaces was studied by IR reflection absorption spectroscopy using s‐ and p‐polarized light incident along different directions. Interpretation of the experimental data is aided using isotopologues and DFT calculations. The presence of numerous species is revealed: intact monomers, a mixed 2D D2O/OD adlayer, an anisotropic bilayer, and H‐bonded 3D structures. The isolated water monomers are identified unambiguously at low temperatures. The thermally induced diffusion of water monomers occurs at elevated temperatures, forming dimers that undergo autocatalytic dissociation via proton transfer. Polarization‐ and azimuth‐resolved IR data provide information on the orientation and strength of H‐bonds within the 2D and 3D structures. Ab initio molecular dynamics simulations reveal strong anharmonic couplings within the H‐bond network.
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Affiliation(s)
- Xiaojuan Yu
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Paul Schwarz
- Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91052, Erlangen, Germany
| | - Alexei Nefedov
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Bernd Meyer
- Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander University Erlangen-Nürnberg (FAU), 91052, Erlangen, Germany
| | - Yuemin Wang
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Christof Wöll
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
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