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Iwai H, Nishino F, Yamamoto T, Kudo M, Tsushida M, Yoshida H, Machida M, Ohyama J. Atomic-Scale 3D Structure of a Supported Pd Nanoparticle Revealed by Electron Tomography with Convolution Neural Network-Based Image Inpainting. SMALL METHODS 2024; 8:e2301163. [PMID: 38044263 DOI: 10.1002/smtd.202301163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/07/2023] [Indexed: 12/05/2023]
Abstract
Electron tomography based on scanning transmission electron microscopy (STEM) is used to analyze 3D structures of metal nanoparticles on the atomic scale. However, in the case of supported metal nanoparticle catalysts, the supporting material may interfere with the 3D reconstruction of metal nanoparticles. In this study, a deep learning-based image inpainting method is applied to high-angle annular dark field (HAADF)-STEM images of a supported metal nanoparticle to predict and remove the background image of the support. The inpainting method can separate an 11 nm Pd nanoparticle from the θ-Al2O3 support in HAADF-STEM images of the θ-Al2O3-supported Pd catalyst. 3D reconstruction of the extracted images of the Pd nanoparticle reveals that the Pd nanoparticle adopts a deformed structure of the cuboctahedron model particle, resulting in high index surfaces, which account for the high catalytic activity for methane combustion. Using the xyz coordinate of each Pd atom, the local Pd-Pd bond distance and its variance in a real supported Pd nanoparticle are visualized, showing large strain and disorder at the Pd-Al2O3 interface. The results demonstrate that 3D atomic-scale analysis enables atomic structure-based understanding and design of supported metal catalysts.
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Affiliation(s)
- Hiroki Iwai
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Fumiya Nishino
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Tomokazu Yamamoto
- The Ultramicroscopy Research Center, Kyushu University, Fukuoka, 819-0395, Japan
| | - Masaki Kudo
- The Ultramicroscopy Research Center, Kyushu University, Fukuoka, 819-0395, Japan
| | | | - Hiroshi Yoshida
- Institute of Science and Engineering, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Masato Machida
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Junya Ohyama
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
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2
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Groppe P, Reichstein J, Carl S, Cuadrado Collados C, Niebuur BJ, Zhang K, Apeleo Zubiri B, Libuda J, Kraus T, Retzer T, Thommes M, Spiecker E, Wintzheimer S, Mandel K. Catalyst Supraparticles: Tuning the Structure of Spray-Dried Pt/SiO 2 Supraparticles via Salt-Based Colloidal Manipulation to Control their Catalytic Performance. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2310813. [PMID: 38700050 DOI: 10.1002/smll.202310813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/10/2024] [Indexed: 05/05/2024]
Abstract
The structure of supraparticles (SPs) is a key parameter for achieving advanced functionalities arising from the combination of different nanoparticle (NP) types in one hierarchical entity. However, whenever a droplet-assisted forced assembly approach is used, e.g., spray-drying, the achievable structure is limited by the inherent drying phenomena of the method. In particular, mixed NP dispersions of differently sized colloids are heavily affected by segregation during the assembly. Herein, the influence of the colloidal arrangement of Pt and SiO2 NPs within a single supraparticulate entity is investigated. A salt-based electrostatic manipulation approach of the utilized NPs is proposed to customize the structure of spray-dried Pt/SiO2 SPs. By this, size-dependent separation phenomena of NPs during solvent evaporation, that limit the catalytic performance in the reduction of 4-nitrophenol, are overcome by achieving even Pt NP distribution. Additionally, the textural properties (pore size and distribution) of the SiO2 pore framework are altered to improve the mass transfer within the material leading to increased catalytic activity. The suggested strategy demonstrates a powerful, material-independent, and universally applicable approach to deliberately customize the structure and functionality of multi-component SP systems. This opens up new ways of colloidal material combinations and structural designs in droplet-assisted forced assembly approaches like spray-drying.
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Affiliation(s)
- Philipp Groppe
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Jakob Reichstein
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
| | - Simon Carl
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058, Erlangen, Germany
| | - Carlos Cuadrado Collados
- Institute of Separation Science and Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany
| | - Bart-Jan Niebuur
- INM - Leibniz-Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany
| | - Kailun Zhang
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany
| | - Benjamin Apeleo Zubiri
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058, Erlangen, Germany
| | - Jörg Libuda
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany
| | - Tobias Kraus
- INM - Leibniz-Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany
- Colloid and Interface Chemistry, Saarland University, Campus D2 2, 66123, Saarbrücken, Germany
| | - Tanja Retzer
- Interface Research and Catalysis, Erlangen Center for Interface Research and Catalysis (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany
| | - Matthias Thommes
- Institute of Separation Science and Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 3, 91058, Erlangen, Germany
| | - Erdmann Spiecker
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058, Erlangen, Germany
| | - Susanne Wintzheimer
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
- Fraunhofer-Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
| | - Karl Mandel
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058, Erlangen, Germany
- Fraunhofer-Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
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3
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Ding R, Padilla Espinosa IM, Loevlie D, Azadehranjbar S, Baker AJ, Mpourmpakis G, Martini A, Jacobs TDB. Size-dependent shape distributions of platinum nanoparticles. NANOSCALE ADVANCES 2022; 4:3978-3986. [PMID: 36133342 PMCID: PMC9470057 DOI: 10.1039/d2na00326k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
While it is well established that nanoparticle shape can depend on equilibrium thermodynamics or growth kinetics, recent computational work has suggested the importance of thermal energy in controlling the distribution of shapes in populations of nanoparticles. Here, we used transmission electron microscopy to characterize the shapes of bare platinum nanoparticles and observed a strong dependence of shape distribution on particle size. Specifically, the smallest nanoparticles (<2.5 nm) had a truncated octahedral shape, bound by 〈111〉 and 〈100〉 facets, as predicted by lowest-energy thermodynamics. However, as particle size increased, the higher-energy 〈110〉 facets became increasingly common, leading to a large population of non-equilibrium truncated cuboctahedra. The observed trends were explained by combining atomistic simulations (both molecular dynamics and an empirical square-root bond-cutting model) with Boltzmann statistics. Overall, this study demonstrates experimentally how thermal energy leads to shape variation in populations of metal nanoparticles, and reveals the dependence of shape distributions on particle size. The prevalence of non-equilibrium facets has implications for metal nanoparticles applications from catalysis to solar energy.
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Affiliation(s)
- Ruikang Ding
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh PA 15261 USA
| | | | - Dennis Loevlie
- Department of Chemical and Petroleum Engineering, University of Pittsburgh Pittsburgh PA 15261 USA
| | - Soodabeh Azadehranjbar
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh PA 15261 USA
| | - Andrew J Baker
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh PA 15261 USA
| | - Giannis Mpourmpakis
- Department of Chemical and Petroleum Engineering, University of Pittsburgh Pittsburgh PA 15261 USA
| | - Ashlie Martini
- Department of Mechanical Engineering, University of California, Merced Merced CA 95343 USA
| | - Tevis D B Jacobs
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh PA 15261 USA
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4
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Chrouda A, Mahmoud Ali Ahmed S, Babiker Elamin M. Preparation of Nanocatalysts Using Deposition Precipitation with Urea: Mechanism, Advantages and Results. CHEMBIOENG REVIEWS 2022. [DOI: 10.1002/cben.202100054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Amani Chrouda
- Majmaah University Departement of Chemistry College of Science Al-Zulfi 11952 Zulfi Saudi Arabia
| | | | - Manahil Babiker Elamin
- Majmaah University Departement of Chemistry College of Science Al-Zulfi 11952 Zulfi Saudi Arabia
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5
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Wen H, Xu X, Cheong S, Lo SC, Chen JH, Chang SLY, Dwyer C. Metrology of convex-shaped nanoparticles via soft classification machine learning of TEM images. NANOSCALE ADVANCES 2021; 3:6956-6964. [PMID: 36132371 PMCID: PMC9417281 DOI: 10.1039/d1na00524c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 10/11/2021] [Indexed: 06/15/2023]
Abstract
The shape of nanoparticles is a key performance parameter for many applications, ranging from nanophotonics to nanomedicines. However, the unavoidable shape variations, which occur even in precision-controlled laboratory synthesis, can significantly impact on the interpretation and reproducibility of nanoparticle performance. Here we have developed an unsupervised, soft classification machine learning method to perform metrology of convex-shaped nanoparticles from transmission electron microscopy images. Unlike the existing methods, which are based on hard classification, soft classification provides significantly greater flexibility in being able to classify both distinct shapes, as well as non-distinct shapes where hard classification fails to provide meaningful results. We demonstrate the robustness of our method on a range of nanoparticle systems, from laboratory-scale to mass-produced synthesis. Our results establish that the method can provide quantitative, accurate, and meaningful metrology of nanoparticle ensembles, even for ensembles entailing a continuum of (possibly irregular) shapes. Such information is critical for achieving particle synthesis control, and, more importantly, for gaining deeper understanding of shape-dependent nanoscale phenomena. Lastly, we also present a method, which we coin the "binary DoG", which achieves significant progress on the challenging problem of identifying the shapes of aggregated nanoparticles.
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Affiliation(s)
- Haotian Wen
- School of Materials Science and Engineering, University of New South Wales Sydney NSW 2052 Australia
| | - Xiaoxue Xu
- School of Mathematical and Physical Sciences, University of Technology, Sydney Ultimo NSW 2007 Australia
| | - Soshan Cheong
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales Sydney NSW 2052 Australia
| | - Shen-Chuan Lo
- Material and Chemical Research Laboratories, Industrial Technology Research Institute Hsinchu Taiwan
| | - Jung-Hsuan Chen
- Material and Chemical Research Laboratories, Industrial Technology Research Institute Hsinchu Taiwan
| | - Shery L Y Chang
- School of Materials Science and Engineering, University of New South Wales Sydney NSW 2052 Australia
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales Sydney NSW 2052 Australia
| | - Christian Dwyer
- Electron Imaging and Spectroscopy Tools PO Box 506 Sans Souci NSW 2219 Australia
- Physics, School of Science, RMIT University Melbourne Victoria 3001 Australia
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6
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Huang K, Shin K, Henkelman G, Crooks RM. Correlating Surface Structures and Electrochemical Activity Using Shape-Controlled Single-Pt Nanoparticles. ACS NANO 2021; 15:17926-17937. [PMID: 34730934 DOI: 10.1021/acsnano.1c06281] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report a method for synthesizing and studying shape-controlled, single Pt nanoparticles (NPs) supported on carbon nanoelectrodes. The key advance is that the synthetic method makes it possible to produce single, electrochemically active NPs with a vast range of crystal structures and sizes. Equally important, the NPs can be fully characterized, and, therefore, the electrochemical properties of the NPs can be directly correlated to the size and structure of a single shape. This makes it possible to directly correlate experimental results to first-principles theory. Because just one well-characterized NP is analyzed at a time, the difficulty of applying a theoretical analysis to an ensemble of NPs having different sizes and structures is avoided. In this article, we report on two specific Pt NP shapes having sizes on the order of 200 nm: concave hexoctahedral (HOH) and concave trapezohedral (TPH). The former has {15 6 1} facets and the latter {10 1 1} facets. The electrochemical properties of these single NPs for the formic acid oxidation (FAO) reaction are compared to those of a single, spherical polycrystalline Pt NP of the same size. Finally, density functional theory, performed prior to the electrochemical studies, were used to interpret the experimental results of the FAO experiments.
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7
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In-situ electrosynthesis Cu-PtBTC MOF-derived nanocomposite modified glassy carbon electrode for highly performance electrocatalysis of hydrogen evolution reaction. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115716] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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8
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Wen H, Luna-Romera JM, Riquelme JC, Dwyer C, Chang SLY. Statistically Representative Metrology of Nanoparticles via Unsupervised Machine Learning of TEM Images. NANOMATERIALS 2021; 11:nano11102706. [PMID: 34685147 PMCID: PMC8539342 DOI: 10.3390/nano11102706] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/07/2021] [Accepted: 10/06/2021] [Indexed: 11/16/2022]
Abstract
The morphology of nanoparticles governs their properties for a range of important applications. Thus, the ability to statistically correlate this key particle performance parameter is paramount in achieving accurate control of nanoparticle properties. Among several effective techniques for morphological characterization of nanoparticles, transmission electron microscopy (TEM) can provide a direct, accurate characterization of the details of nanoparticle structures and morphology at atomic resolution. However, manually analyzing a large number of TEM images is laborious. In this work, we demonstrate an efficient, robust and highly automated unsupervised machine learning method for the metrology of nanoparticle systems based on TEM images. Our method not only can achieve statistically significant analysis, but it is also robust against variable image quality, imaging modalities, and particle dispersions. The ability to efficiently gain statistically significant particle metrology is critical in advancing precise particle synthesis and accurate property control.
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Affiliation(s)
- Haotian Wen
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Correspondence: (H.W.); (S.L.Y.C.)
| | - José María Luna-Romera
- Software and Computing Systems, Universidad de Sevilla, 41004 Seville, Spain; (J.M.L.-R.); (J.C.R.)
| | - José C. Riquelme
- Software and Computing Systems, Universidad de Sevilla, 41004 Seville, Spain; (J.M.L.-R.); (J.C.R.)
| | - Christian Dwyer
- Electron Imaging and Spectroscopy Tools, Sydney, NSW 2219, Australia;
| | - Shery L. Y. Chang
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Mark Wainwright Analytical Centre, Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052, Australia
- Correspondence: (H.W.); (S.L.Y.C.)
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9
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Weber ML, Wilhelm M, Jin L, Breuer U, Dittmann R, Waser R, Guillon O, Lenser C, Gunkel F. Exsolution of Embedded Nanoparticles in Defect Engineered Perovskite Layers. ACS NANO 2021; 15:4546-4560. [PMID: 33635643 DOI: 10.1021/acsnano.0c08657] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Exsolution phenomena are highly debated as efficient synthesis routes for nanostructured composite electrode materials for the application in solid oxide cells (SOCs) and the development of next-generation electrochemical devices for energy conversion. Utilizing the instability of perovskite oxides, doped with electrocatalytically active elements, highly dispersed nanoparticles can be prepared at the perovskite surface under the influence of a reducing heat treatment. For the systematic study of the mechanistic processes governing metal exsolution, epitaxial SrTi0.9Nb0.05Ni0.05O3-δ thin films of well-defined stoichiometry are synthesized and employed as model systems to investigate the interplay of defect structures and exsolution behavior. Spontaneous phase separation and the formation of dopant-rich features in the as-synthesized thin film material is revealed by high-resolution transmission electron microscopy (HR-TEM) investigations. The resulting nanostructures are enriched by nickel and serve as preformed nuclei for the subsequent exsolution process under reducing conditions, which reflects a so far unconsidered process drastically affecting the understanding of nanoparticle exsolution phenomena. Using an approach of combined morphological, chemical, and structural analysis of the exsolution response, a limitation of the exsolution dynamics for nonstoichiometric thin films is found to be correlated to a distortion of the perovskite host lattice. Consequently, the incorporation of defect structures results in a reduced particle density at the perovskite surface, presumably by trapping of nanoparticles in the oxide bulk.
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Affiliation(s)
- Moritz L Weber
- Peter Gruenberg Institute (PGI-7), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Institute of Energy and Climate Research (IEK-1), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Juelich-Aachen Research Alliance (JARA-FIT), 52425 Juelich, Germany
- Institute of Mineral Engineering (GHI), RWTH Aachen University, 52062 Aachen, Germany
| | - Marek Wilhelm
- Peter Gruenberg Institute (PGI-6), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Lei Jin
- Juelich-Aachen Research Alliance (JARA-FIT), 52425 Juelich, Germany
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Uwe Breuer
- Central Institute for Engineering, Electronics and Analytics (ZEA-3), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Regina Dittmann
- Peter Gruenberg Institute (PGI-7), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Juelich-Aachen Research Alliance (JARA-FIT), 52425 Juelich, Germany
| | - Rainer Waser
- Peter Gruenberg Institute (PGI-7), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Juelich-Aachen Research Alliance (JARA-FIT), 52425 Juelich, Germany
- Institute for Electronic Materials II (IWE II), RWTH Aachen University, 52056 Aachen, Germany
| | - Olivier Guillon
- Institute of Energy and Climate Research (IEK-1), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Institute of Mineral Engineering (GHI), RWTH Aachen University, 52062 Aachen, Germany
- Juelich-Aachen Research Alliance (JARA-Energy), 52425 Juelich, Germany
| | - Christian Lenser
- Institute of Energy and Climate Research (IEK-1), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Felix Gunkel
- Peter Gruenberg Institute (PGI-7), Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Juelich-Aachen Research Alliance (JARA-FIT), 52425 Juelich, Germany
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10
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Parker AJ, Motevalli B, Opletal G, Barnard AS. The pure and representative types of disordered platinum nanoparticles from machine learning. NANOTECHNOLOGY 2021; 32:095404. [PMID: 33212430 DOI: 10.1088/1361-6528/abcc23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The development of interpretable structure/property relationships is a cornerstone of nanoscience, but can be challenging when the structural diversity and complexity exceeds our ability to characterise it. This is often the case for imperfect, disordered and amorphous nanoparticles, where even the nomenclature can be unspecific. Disordered platinum nanoparticles have exhibited superior performance for some reactions, which makes a systematic way of describing them highly desirable. In this study we have used a diverse set of disorder platinum nanoparticles and machine learning to identify the pure and representative structures based on their similarity in 121 dimensions. We identify two prototypes that are representative of separable classes, and seven archetypes that are the pure structures on the convex hull with which all other possibilities can be described. Together these nine nanoparticles can explain all of the variance in the set, and can be described as either single crystal, twinned, spherical or branched; with or without roughened surfaces. This forms a robust sub-set of platinum nanoparticle upon which to base further work, and provides a theoretical basis for discussing structure/property relationships of platinum nanoparticles that are not geometrically ideal.
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Affiliation(s)
| | | | | | - Amanda S Barnard
- ANU Research School of Computer Science, Acton ACT 2601, Australia
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11
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Kim S, Kwag J, Machello C, Kang S, Heo J, Reboul CF, Kang D, Kang S, Shim S, Park SJ, Kim BH, Hyeon T, Ercius P, Elmlund H, Park J. Correlating 3D Surface Atomic Structure and Catalytic Activities of Pt Nanocrystals. NANO LETTERS 2021; 21:1175-1183. [PMID: 33416334 DOI: 10.1021/acs.nanolett.0c04873] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Active sites and catalytic activity of heterogeneous catalysts is determined by their surface atomic structures. However, probing the surface structure at an atomic resolution is difficult, especially for solution ensembles of catalytic nanocrystals, which consist of heterogeneous particles with irregular shapes and surfaces. Here, we constructed 3D maps of the coordination number (CN) and generalized CN (CN_) for individual surface atoms of sub-3 nm Pt nanocrystals. Our results reveal that the synthesized Pt nanocrystals are enclosed by islands of atoms with nonuniform shapes that lead to complex surface structures, including a high ratio of low-coordination surface atoms, reduced domain size of low-index facets, and various types of exposed high-index facets. 3D maps of CN_ are directly correlated to catalytic activities assigned to individual surface atoms with distinct local coordination structures, which explains the origin of high catalytic performance of small Pt nanocrystals in important reactions such as oxygen reduction reactions and CO electro-oxidation.
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Affiliation(s)
- Sungin Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Jimin Kwag
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Chiara Machello
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- ARC Centre of Excellence for Advanced Molecular Imaging, Clayton, Victoria 3800, Australia
| | - Sungsu Kang
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Junyoung Heo
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Cyril F Reboul
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- ARC Centre of Excellence for Advanced Molecular Imaging, Clayton, Victoria 3800, Australia
| | - Dohun Kang
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Seulki Kang
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Sangdeok Shim
- Department of Chemistry, Sunchon National University, Suncheon 57922, Republic of Korea
| | - So-Jung Park
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Byung Hyo Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
- Department of Organic Materials and Fiber Engineering, Soongsil University, Seoul 06978, Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Peter Ercius
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Hans Elmlund
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- ARC Centre of Excellence for Advanced Molecular Imaging, Clayton, Victoria 3800, Australia
| | - Jungwon Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
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12
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Plodinec M, Nerl HC, Farra R, Willinger MG, Stotz E, Schlögl R, Lunkenbein T. Versatile Homebuilt Gas Feed and Analysis System for Operando TEM of Catalysts at Work. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:220-228. [PMID: 32115001 DOI: 10.1017/s143192762000015x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding how catalysts work during chemical reactions is crucial when developing efficient catalytic materials. The dynamic processes involved are extremely sensitive to changes in pressure, gas environment and temperature. Hence, there is a need for spatially resolved operando techniques to investigate catalysts under working conditions and over time. The use of dedicated operando techniques with added detection of catalytic conversion presents a unique opportunity to study the mechanisms underlying the catalytic reactions systematically. Herein, we report on the detailed setup and technical capabilities of a modular, homebuilt gas feed system directly coupled to a quadrupole mass spectrometer, which allows for operando transmission electron microscopy (TEM) studies of heterogeneous catalysts. The setup is compatible with conventional, commercially available gas cell TEM holders, making it widely accessible and reproducible by the community. In addition, the operando functionality of the setup was tested using CO oxidation over Pt nanoparticles.
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Affiliation(s)
- Milivoj Plodinec
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Hannah C Nerl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Ramzi Farra
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Marc G Willinger
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Eugen Stotz
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Robert Schlögl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
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13
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Plodinec M, Nerl HC, Girgsdies F, Schlögl R, Lunkenbein T. Insights into Chemical Dynamics and Their Impact on the Reactivity of Pt Nanoparticles during CO Oxidation by Operando TEM. ACS Catal 2020. [DOI: 10.1021/acscatal.9b03692] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Milivoj Plodinec
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Hannah C. Nerl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Frank Girgsdies
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Robert Schlögl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
- Max Planck Institute for Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany
| | - Thomas Lunkenbein
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
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14
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Kamiński M, Jurkiewicz K, Burian A, Bródka A. The structure of gold nanoparticles: molecular dynamics modeling and its verification by X-ray diffraction. J Appl Crystallogr 2020. [DOI: 10.1107/s1600576719014511] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Noble metal nanoparticles exhibit unique physical, chemical, biomedical, catalytic and optical properties. Understanding these properties and further development of production methods entail detailed knowledge of the structure at the atomic scale. Gold nanoparticles with multimodal size distribution were synthesized on porous silica and their atomic scale structure was studied by X-ray diffraction. The obtained experimental data are compared with molecular dynamics simulations. Spherical models of the Au nanoparticles, defined by ensembles of the Cartesian coordinates of constituent atoms, were generated and their geometry was optimized by applying theLAMMPSsoftware. The comparison was performed in both reciprocal and real space. A good agreement is achieved for the models with disorder that can be related to surface relaxation effects and vacancy defects. The approach adopted here may have wider applications for further structural studies of other nanomaterials, offering direct verification of simulation results by experiment.
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15
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Investigation of selective chemisorption of fcc and hcp Ru nanoparticles using X-ray photoelectron spectroscopy analysis. J Catal 2019. [DOI: 10.1016/j.jcat.2019.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Long W, Mu X, Wang JY, Xu F, Yang J, Wang J, Sun S, Chen J, Sun YM, Wang H, Zhang XD. Dislocation Engineered PtPdMo Alloy With Enhanced Antioxidant Activity for Intestinal Injury. Front Chem 2019; 7:784. [PMID: 31803720 PMCID: PMC6873609 DOI: 10.3389/fchem.2019.00784] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 10/30/2019] [Indexed: 12/30/2022] Open
Abstract
Radiotherapy is the mainstay for abdomen and pelvis cancers treatment. However, high energy ray would inflict gastrointestinal (GI) system and adversely disrupt the treatment. The anti-oxidative agents provide a potential route for protecting body from radiation-induced injuries. Herein, highly catalytic nanocubes with dislocation structure are developed for treatment of intestinal injury. Structural and catalytic properties show that Mo incorporation can enhance antioxidant activity by dislocation structure in the alloy. In vitro studies showed that PtPdMo improved cell survival by scavenging radiation-induced ROS accumulation. Furthermore, after animals were exposed to lethal dose of radiation, the survival was increased by 50% with the PtPdMo i.p. treatment. Radioprotection mechanism revealed that PtPdMo alleviated the oxidative stress in multi-organs especially the small intestine by inhibiting intestinal epithelium apoptosis, reducing DNA strands breaks and enhancing repairing ability. In addition, PtPdMo protected hematopoietic system by improving the number of bone marrow and peripheral blood cells.
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Affiliation(s)
- Wei Long
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Xiaoyu Mu
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
| | - Jun-Ying Wang
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
| | - Fujuan Xu
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
| | - Jiang Yang
- State Key Laboratory of Oncology in South China Collaborative Innovation Center for Cancer Medicine Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jingya Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Si Sun
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
| | - Jing Chen
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
| | - Yuan-Ming Sun
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Hao Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Xiao-Dong Zhang
- Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin, China
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17
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Zhang Y, McDonnell M, Liu W, Tucker MG. Reverse Monte Carlo modeling for low-dimensional systems. J Appl Crystallogr 2019. [DOI: 10.1107/s160057671901080x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Reverse Monte Carlo (RMC) is one of the commonly used approaches for modeling total scattering data. However, to extend the capability of the RMC method for refining the structure of nanomaterials, the dimensionality and finite size need to be considered when calculating the pair distribution function (PDF). To achieve this, the simulation box must be set up to remove the periodic boundary condition in one, two or three of the dimensions. This then requires a correction to be applied for the difference in number density between the real system and the simulation box. In certain circumstances an analytical correction for the uncorrelated pairings of atoms is also applied. The validity and applicability of our methodology is demonstrated by applying the algorithms to simulate the PDF patterns of carbon systems with various dimensions, and also by using them to fit experimental data of CuO nanoparticles. This alternative approach for characterizing the local structure of nano-systems with the total scattering technique will be made available via the RMCProfile package. The theoretical formulation and detailed explanation of the analytical corrections for low-dimensional systems – 2D nanosheets, 1D nanowires and 0D nanoparticles – is also given.
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18
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Yan T, Sun B, Barnard AS. Predicting archetypal nanoparticle shapes using a combination of thermodynamic theory and machine learning. NANOSCALE 2018; 10:21818-21826. [PMID: 30452032 DOI: 10.1039/c8nr07341d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Machine learning is a useful way of identifying representative or pure nanoparticle shapes as part of a larger ensemble, but its predictive capabilities can be limited when a large dataset of candidate structures must already exist. Ideally one would like to use machine learning to define the ideal dataset for future, more computationally intensive, studies before a significant amount of resources are consumed. In this work we combine an established analytical phenomenological model and statistical machine learning to predict the archetypes and prototypes of a diverse ensemble of 2380 platinum nanoparticle morphologies developed with less than twenty input electronic structure simulations. By parameterising a size- and shape-dependent thermodynamic model, probabilities are assigned to seventeen different shapes between three and thirty nanometres, which together with structural features such as nanoparticle diameter, surface area, sphericity and facet configuration form the basis for archetypal analysis and K-means clustering. Using this approach we rapidly identify six "pure" archetypes and twelve "representative" prototypes that can be used in future computational studies of properties such as catalysis.
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Affiliation(s)
- Tao Yan
- Molecular and Materials Modelling, Data61 CSIRO, Door 34 Goods Shed, Village St, Docklands, VIC 3008, Australia.
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19
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A Review of Dendrimer-Encapsulated Metal Nanocatalysts Applied in the Fine Chemical Transformations. Catal Letters 2018. [DOI: 10.1007/s10562-018-2584-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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20
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Longbottom BW, Bon SAF. Improving the engine power of a catalytic Janus-sphere micromotor by roughening its surface. Sci Rep 2018; 8:4622. [PMID: 29545556 PMCID: PMC5854611 DOI: 10.1038/s41598-018-22917-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 02/28/2018] [Indexed: 12/13/2022] Open
Abstract
Microspheres with catalytic caps have become a popular model system for studying self-propelled colloids. Existing experimental studies involve predominantly "smooth" particle surfaces. In this study we determine the effect of irregular surface deformations on the propulsive mechanism with a particular focus on speed. The particle surfaces of polymer microspheres were deformed prior to depositing a layer of platinum which resulted in the formation of nanoscopic pillars of catalyst. Self-propulsion was induced upon exposure of the micromotors to hydrogen peroxide, whilst they were dispersed in water. The topological surface features were shown to boost speed (~2×) when the underlying deformations are small (nanoscale), whilst large deformations afforded little difference despite a substantial apparent catalytic surface area. Colloids with deformed surfaces were more likely to display a mixture of rotational and translational propulsion than their "smooth" counterparts.
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Affiliation(s)
- Brooke W Longbottom
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, U.K
| | - Stefan A F Bon
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, U.K..
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21
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Jurkiewicz K, Kamiński M, Glajcar W, Woźnica N, Julienne F, Bartczak P, Polański J, Lelątko J, Zubko M, Burian A. Paracrystalline structure of gold, silver, palladium and platinum nanoparticles. J Appl Crystallogr 2018. [DOI: 10.1107/s1600576718001723] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Metallic nanoparticles are of great importance because of their unique physical, chemical, antimicrobial, diagnostic, therapeutic, biomedical, sensing, biosensing, catalytic and optical properties. Detailed knowledge of the atomic scale structure of these materials is essential for understanding their activities and for exploiting their potential. This paper reports structural studies of silica-supported silver, gold, palladium and platinum nanoparticles using X-ray diffraction and high-resolution transmission electron microscopy. Electron microscopy observation allowed the determination of nanoparticle sizes, which were estimated to be in the range of 45–470 Å, and their distribution. The obtained histograms exhibit a multimodal distribution of the investigated nanoparticle sizes. The X-ray diffraction data were analyzed using the Rietveld method in the form of Williamson–Hall plots, thePDFguifitting procedure and model-based simulation. The Williamson–Hall plots provide evidence for the presence of strain in all investigated samples. ThePDFguifitting results indicate that the investigated nanoparticles consist of atomic clusters with different sizes and degrees of disorder as well as slightly different lattice parameters. The detailed structural characterization performedviamodel-based simulations proves that all samples exhibit a face-centered cubic type structure with paracrystalline distortion. The degree of disorder predicted by the paracrystalline theory is correlated with the sizes of the nanoparticles. The catalytic properties of the investigated noble metals are discussed in relation to their disordered structure.
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22
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Richard MI, Fernández S, Eymery J, Hofmann JP, Gao L, Carnis J, Labat S, Favre-Nicolin V, Hensen EJM, Thomas O, Schülli TU, Leake SJ. Crystallographic orientation of facets and planar defects in functional nanostructures elucidated by nano-focused coherent diffractive X-ray imaging. NANOSCALE 2018; 10:4833-4840. [PMID: 29473085 DOI: 10.1039/c7nr07990g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The physical and chemical properties of nanostructures depend on their surface facets. Here, we exploit a pole figure approach to determine the three-dimensional orientation matrix of a nanostructure from a single Bragg reflection measured with a coherent nano-focused X-ray beam. The signature of any truncated (faceted) crystal produces a crystal truncation rod, which corresponds to a streak of intensity in reciprocal space normal to the surface. When two or more non-parallel facets are present, both the crystal orientation and the crystal facets can be identified. This enables facets to be rapidly indexed and uncommon facets, and planar defects, that have been difficult to study before to be identified. We demonstrate the technique with (i) epitaxial core-shell InGaN/GaN multiple quantum-wells grown on GaN nanowires, where surface facets and planar defects are determined, and (ii) single randomly oriented highly faceted tetrahedrahexal Pt nanoparticles. The methodology is applicable to a broad range of nanocrystals and provides a unique insight into the connection between structure and properties of nanomaterials.
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Affiliation(s)
- Marie-Ingrid Richard
- Aix Marseille Université, CNRS, Université de Toulon, IM2NP UMR 7334, 13397, Marseille, France.
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23
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De Backer A, Jones L, Lobato I, Altantzis T, Goris B, Nellist PD, Bals S, Van Aert S. Three-dimensional atomic models from a single projection using Z-contrast imaging: verification by electron tomography and opportunities. NANOSCALE 2017; 9:8791-8798. [PMID: 28621785 DOI: 10.1039/c7nr02656k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In order to fully exploit structure-property relations of nanomaterials, three-dimensional (3D) characterization at the atomic scale is often required. In recent years, the resolution of electron tomography has reached the atomic scale. However, such tomography typically requires several projection images demanding substantial electron dose. A newly developed alternative circumvents this by counting the number of atoms across a single projection. These atom counts can be used to create an initial atomic model with which an energy minimization can be applied to obtain a relaxed 3D reconstruction of the nanoparticle. Here, we compare, at the atomic scale, this single projection reconstruction approach with tomography and find an excellent agreement. This new approach allows for the characterization of beam-sensitive materials or where the acquisition of a tilt series is impossible. As an example, the utility is illustrated by the 3D atomic scale characterization of a nanodumbbell on an in situ heating holder of limited tilt range.
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Affiliation(s)
- A De Backer
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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24
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Reinhardt J, Hoppe R, Hofmann G, Damsgaard CD, Patommel J, Baumbach C, Baier S, Rochet A, Grunwaldt JD, Falkenberg G, Schroer CG. Beamstop-based low-background ptychography to image weakly scattering objects. Ultramicroscopy 2016; 173:52-57. [PMID: 27912167 DOI: 10.1016/j.ultramic.2016.11.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/28/2016] [Accepted: 11/08/2016] [Indexed: 11/29/2022]
Abstract
In recent years, X-ray ptychography has been established as a valuable tool for high-resolution imaging. Nevertheless, the spatial resolution and sensitivity in coherent diffraction imaging are limited by the signal that is detected over noise and over background scattering. Especially, coherent imaging of weakly scattering specimens suffers from incoherent background that is generated by the interaction of the central beam with matter along its propagation path in particular close to and inside of the detector. Common countermeasures entail evacuated flight tubes or detector-side beamstops, which improve the experimental setup in terms of background reduction or better coverage of high dynamic range in the diffraction patterns. Here, we discuss an alternative approach: we combine two ptychographic scans with and without beamstop and reconstruct them simultaneously taking advantage of the complementary information contained in the two scans. We experimentally demonstrate the potential of this scheme for hard X-ray ptychography by imaging a weakly scattering object composed of catalytic nanoparticles and provide the analysis of the signal-to-background ratio in the diffraction patterns.
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Affiliation(s)
| | - Robert Hoppe
- Institute of Structural Physics, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Georg Hofmann
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany
| | - Christian D Damsgaard
- Center for Electron Nanoscopy and Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Jens Patommel
- Institute of Structural Physics, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Christoph Baumbach
- Institute of Structural Physics, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Sina Baier
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany
| | - Amélie Rochet
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany
| | - Jan-Dierk Grunwaldt
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany
| | | | - Christian G Schroer
- Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany; Department Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany
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25
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Schröder F, Sharma UK, Mertens M, Devred F, Debecker DP, Luque R, Eycken EVVD. Silver-Nanoparticle-Catalyzed Dearomatization of Indoles toward 3-Spiroindolenines via a 5-exo-dig Spirocyclization. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02443] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Felix Schröder
- Department
of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Upendra K. Sharma
- Department
of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Martijn Mertens
- Department
of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - François Devred
- Institute
of Condensed Matter and Nanosciences—IMCN, Université Catholique de Louvain (UCL), Place Louis Pasteur, 1, Box L4.01.09, B-1348 Louvain-la-Neuve, Belgium
| | - Damien P. Debecker
- Institute
of Condensed Matter and Nanosciences—IMCN, Université Catholique de Louvain (UCL), Place Louis Pasteur, 1, Box L4.01.09, B-1348 Louvain-la-Neuve, Belgium
| | - Rafael Luque
- Departamento
de Química Organica, Campus de Rabanales, Edificio C-3 (Marie Curie−Anexo),
Carretera Nacional IV−A, Km. 396, 14014 Córdoba, Spain
| | - Erik V. Van der Eycken
- Department
of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, B-3001 Leuven, Belgium
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26
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27
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de Morais RF, Kerber T, Calle-Vallejo F, Sautet P, Loffreda D. Capturing Solvation Effects at a Liquid/Nanoparticle Interface by Ab Initio Molecular Dynamics: Pt 201 Immersed in Water. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5312-5319. [PMID: 27531424 DOI: 10.1002/smll.201601307] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/05/2016] [Indexed: 06/06/2023]
Abstract
Solvation can substantially modify the adsorption properties of heterogeneous catalysts. Although essential for achieving realistic theoretical models, assessing such solvent effects over nanoparticles is challenging from a computational standpoint due to the complexity of those liquid/metal interfaces. This effect is investigated by ab initio molecular dynamics simulations at 350 K of a large platinum nanoparticle immersed in liquid water. The first solvation layer contains twice as much physisorbed water molecules above the terraces, than chemisorbed ones located only at edges and corners. The solvent stabilizes the binding energy of chemisorbates: 66% of the total gain comes from interactions with physisorbed molecules and 34% from the influence of bulk liquid.
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Affiliation(s)
- Rodrigo Ferreira de Morais
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F-69342, Lyon, France
| | - Torsten Kerber
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F-69342, Lyon, France
| | - Federico Calle-Vallejo
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F-69342, Lyon, France
- Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300, RA, Leiden, The Netherlands
| | - Philippe Sautet
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F-69342, Lyon, France
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | - David Loffreda
- Univ Lyon, Ens de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F-69342, Lyon, France.
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28
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Li X, Cai T, Kang ET. Hairy Hybrid Nanorattles of Platinum Nanoclusters with Dual-Responsive Polymer Shells for Confined Nanocatalysis. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00945] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Xue Li
- Key
Laboratory of Biomedical Polymers of Ministry of Education, College
of Chemistry and Molecular Science, Wuhan University, Wuhan, Hubei 430072, P. R. China
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260
| | - Tao Cai
- Key
Laboratory of Biomedical Polymers of Ministry of Education, College
of Chemistry and Molecular Science, Wuhan University, Wuhan, Hubei 430072, P. R. China
| | - En-Tang Kang
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260
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29
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Kale MJ, Christopher P. Utilizing Quantitative in Situ FTIR Spectroscopy To Identify Well-Coordinated Pt Atoms as the Active Site for CO Oxidation on Al2O3-Supported Pt Catalysts. ACS Catal 2016. [DOI: 10.1021/acscatal.6b01128] [Citation(s) in RCA: 181] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew J. Kale
- Department of Chemical & Environmental Engineering, ‡Program in Materials Science and Engineering, and §UCR Center for Catalysis, University of California, Riverside, California 92521, United States
| | - Phillip Christopher
- Department of Chemical & Environmental Engineering, ‡Program in Materials Science and Engineering, and §UCR Center for Catalysis, University of California, Riverside, California 92521, United States
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30
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López-Haro M, Yoshida K, Del Río E, Pérez-Omil JA, Boyes ED, Trasobares S, Zuo JM, Gai PL, Calvino JJ. Strain Field in Ultrasmall Gold Nanoparticles Supported on Cerium-Based Mixed Oxides. Key Influence of the Support Redox State. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4313-22. [PMID: 27058299 DOI: 10.1021/acs.langmuir.6b00758] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Using a method that combines experimental and simulated Aberration-Corrected High Resolution Electron Microscopy images with digital image processing and structure modeling, strain distribution maps within gold nanoparticles relevant to real powder type catalysts, i.e., smaller than 3 nm, and supported on a ceria-based mixed oxide have been determined. The influence of the reduction state of the support and particle size has been examined. In this respect, it has been proven that reduction even at low temperatures induces a much larger compressive strain on the first {111} planes at the interface. This increase in compression fully explains, in accordance with previous DFT calculations, the loss of CO adsorption capacity of the interface area previously reported for Au supported on ceria-based oxides.
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Affiliation(s)
- Miguel López-Haro
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Facultad Ciencias. Universidad de Cádiz . Campus Rio San Pedro, Puerto Real, 11510 Cádiz, Spain
- Université Grenoble Alpes , F-38000 Grenoble, France CEA-INAC/UJF-Grenoble 1 UMR-E, SP2M, LEMMA, Minatec Grenoble, F-38054, France
| | - Kenta Yoshida
- Departments of Chemistry and Physics, University of York , The York JEOL Nanocentre, Heslington, York YO10 5DD, United Kingdom
| | - Eloy Del Río
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Facultad Ciencias. Universidad de Cádiz . Campus Rio San Pedro, Puerto Real, 11510 Cádiz, Spain
| | - José A Pérez-Omil
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Facultad Ciencias. Universidad de Cádiz . Campus Rio San Pedro, Puerto Real, 11510 Cádiz, Spain
| | - Edward D Boyes
- Departments of Chemistry and Physics, University of York , The York JEOL Nanocentre, Heslington, York YO10 5DD, United Kingdom
| | - Susana Trasobares
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Facultad Ciencias. Universidad de Cádiz . Campus Rio San Pedro, Puerto Real, 11510 Cádiz, Spain
| | - Jian-Min Zuo
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , 1304 West Green Street, Urbana, Illinois 61801, United States
| | - Pratibha L Gai
- Departments of Chemistry and Physics, University of York , The York JEOL Nanocentre, Heslington, York YO10 5DD, United Kingdom
| | - José J Calvino
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Facultad Ciencias. Universidad de Cádiz . Campus Rio San Pedro, Puerto Real, 11510 Cádiz, Spain
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31
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32
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Han JH, Bae JH, Han D, Chung TD. Confined Molecular Dynamics for Suppressing Kinetic Loss in Sugar Fuel Cell. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2015.11.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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33
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Sinkler W, Sanchez SI, Bradley SA, Wen J, Mishra B, Kelly SD, Bare SR. Aberration‐Corrected Transmission Electron Microscopy and In Situ XAFS Structural Characterization of Pt/γ‐Al
2
O
3
Nanoparticles. ChemCatChem 2015. [DOI: 10.1002/cctc.201500784] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
| | | | | | - Jianguo Wen
- Electron Microscopy Center—Center for Nanoscale Materials, Nanoscience and Technology Division, Argonne National Laboratory Argonne IL 60439 USA
| | - Bhoopesh Mishra
- Physics Department, Illinois Institute of Technology Chicago IL 60016 USA
| | | | - Simon R. Bare
- UOP LLC, a Honeywell Company Des Plaines IL 60017 USA
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34
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Solla-Gullon J, Garnier E, Feliu JM, Leoni M, Leonardi A, Scardi P. Structure and morphology of shape-controlled Pd nanocrystals. J Appl Crystallogr 2015. [DOI: 10.1107/s1600576715015964] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pd nanocrystals were produced with uniform truncated-cube shape and a narrow size distribution, yielding controlled surface area fractions from low Miller index ({100}, {110}, {111}) crystalline facets. Details on the structure and morphology of the nanocrystals were obtained by combining X-ray powder diffraction line profile analysis, high-resolution transmission electron microscopy and surface electrochemistry based on Cu underpotential deposition.
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35
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Oxygen reduction on nanostructured platinum surfaces in acidic media: Promoting effect of surface steps and ideal response of Pt(111). Catal Today 2015. [DOI: 10.1016/j.cattod.2014.05.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Qi K, Wang Q, Zheng W, Zhang W, Cui X. Porous single-crystalline palladium nanoflowers with enriched {100} facets for highly enhanced ethanol oxidation. NANOSCALE 2014; 6:15090-15097. [PMID: 25370157 DOI: 10.1039/c4nr05761a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Palladium porous single-crystalline nanoflowers (PSNFs) with enriched high catalytic activity {100} facets were synthesized using a mild and controllable seed mediated growth method. The growth mechanism of the Pd PSNFs was investigated using time dependent morphology evolution through TEM imaging. Due to the specific structure, Pd PSNFs show highly enhanced ethanol oxidation reaction (EOR) activity, high EOR anti-poisoning and stability, much better than Pd nanocubes, {111} facets dominated dendritic urchin-like Pd nanoparticles and Pd black.
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Affiliation(s)
- Kun Qi
- Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.
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37
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Barnard AS. Clarifying stability, probability and population in nanoparticle ensembles. NANOSCALE 2014; 6:9983-9990. [PMID: 24831157 DOI: 10.1039/c4nr01504e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Though theoretical and computational studies typically agree on the low energy, equilibrium structure of metallic nanoparticles, experimental studies report on samples with a distribution of shapes; including high-index, non-equilibrium morphologies. This apparent inconsistency is not due to inaccuracy on either side, nor the result of unquantifiable competition between thermodynamic and kinetic influences, but rather a lack of clarity about what is being inferred. The thermodynamic stability, statistical probability, and the observed population of a given structure are all straightforward to determine, provided an ensemble of possible configurations is included at the outset. To clarify this relationship, a combination of electronic structure simulations and mathematical models will be used to predict the relative stabilities, probability and population of various shapes of Ag, Au, Pd and Pt nanoparticles, and provide some explanation for the observation of high-index, non-equilibrium morphologies. As we will see, a nanoparticle can be in the ground-state, and therefore most thermodynamically stable, but can still be in the minority.
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Affiliation(s)
- Amanda S Barnard
- CSIRO Materials Science and Engineering, 343 Royal Parade, Parkville, Victoria 3052, Australia.
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38
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Yankovich AB, Berkels B, Dahmen W, Binev P, Sanchez SI, Bradley SA, Li A, Szlufarska I, Voyles PM. Picometre-precision analysis of scanning transmission electron microscopy images of platinum nanocatalysts. Nat Commun 2014; 5:4155. [DOI: 10.1038/ncomms5155] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 05/19/2014] [Indexed: 11/09/2022] Open
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39
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Tang W, Zhou T, Zhang C, Fan FR, Han CB, Wang ZL. A power-transformed-and-managed triboelectric nanogenerator and its applications in a self-powered wireless sensing node. NANOTECHNOLOGY 2014; 25:225402. [PMID: 24833476 DOI: 10.1088/0957-4484/25/22/225402] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A power-transformed-and-managed triboelectric nanogenerator (PTM-TENG) is invented that is intended to give regulated power output for driving electronics. The design is based on a synchronized mechanical agitation that not only drives the TENG but also switches the connections for the capacitors for lowering the output voltage and increasing the output charges. An energy preservation efficiency of >95% was demonstrated. The PTM-TENG not only detected the external mechanical triggering action but also generated enough power for sending out an infrared signal.
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40
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Wang S, Wu N. Selecting the swimming mechanisms of colloidal particles: bubble propulsion versus self-diffusiophoresis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3477-86. [PMID: 24593832 DOI: 10.1021/la500182f] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Bubble propulsion and self-diffusiophoresis are two common mechanisms that can drive autonomous motion of microparticles in hydrogen peroxide. Although microtubular particles, when coated with platinum in their interior concave surfaces, can propel due to the formation and release of bubbles from one end, the convex Janus particles usually do not generate any visible bubble. They move primarily due to the self-diffusiophoresis. Coincidentally, the platinum films on those particles were typically coated by physical evaporation. In this paper, we use a simple chemical deposition method to make platinum-polystyrene Janus dimers. Surprisingly, those particles are propelled by periodic growth and collapse of bubbles on the platinum-coated lobes. We find that both high catalytic activity and rough surface are necessary to change the propulsion mode from self-diffusiophoresis to bubble propulsion. Our Janus dimers, with combined geometric and interfacial anisotropy, also exhibit distinctive motions at the respective stages of bubble growth and collapse, which differ by 5-6 orders of magnitude in time. Our study not only provides insight into the link between self-diffusiophoresis and bubble propulsion but also reveals the intriguing impacts of the combined geometric and interfacial anisotropy on self-propulsion of particles.
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Affiliation(s)
- Sijia Wang
- Department of Chemical and Biological Engineering, Colorado School of Mines , Golden, Colorado 80401, United States
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41
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Porous dendritic platinum nanotubes with extremely high activity and stability for oxygen reduction reaction. Sci Rep 2013; 3:1526. [PMID: 23524665 PMCID: PMC3607176 DOI: 10.1038/srep01526] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 01/21/2013] [Indexed: 11/23/2022] Open
Abstract
Controlling the morphology of Pt nanostructures can provide opportunities to greatly increase their activity and stability. Porous dendritic Pt nanotubes were successfully synthesized by a facile, cost-effective aqueous solution method at room temperature in large scale. These unique structures are porous, hollow, hierarchical, and single crystalline, which not only gives them a large surface area with high catalyst utilization, but also improves mass transport and gas diffusion. These novel Pt structures exhibited significantly improved catalytic activity (4.4 fold) for oxygen reduction reaction (ORR) and greatly enhanced durability (6.1 fold) over that of the state-of-the-art commercial Pt/C catalyst. This work provides a promising approach to the design of highly efficient next-generation electrocatalysts.
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42
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Del Angel P, Hernandez-Pichardo M, Montoya de la Fuente J. Aberration-corrected HRTEM study of Mn-doped tungstated zirconia catalysts. Catal Today 2013. [DOI: 10.1016/j.cattod.2012.09.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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43
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Wang Y, Zhang L, Li F, Gu B. A novel Pt nanosponge foil with high activity for oxygen reduction reaction. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.03.178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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44
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Pozo-Gonzalo C, Kartachova O, Torriero AA, Howlett PC, Glushenkov AM, Fabijanic DM, Chen Y, Poissonnet S, Forsyth M. Nanoporous transition metal oxynitrides as catalysts for the oxygen reduction reaction. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Mehraeen S, McKeown JT, Deshmukh PV, Evans JE, Abellan P, Xu P, Reed BW, Taheri ML, Fischione PE, Browning ND. A (S)TEM gas cell holder with localized laser heating for in situ experiments. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:470-478. [PMID: 23452391 DOI: 10.1017/s1431927612014419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The advent of aberration correction for transmission electron microscopy has transformed atomic resolution imaging into a nearly routine technique for structural analysis. Now an emerging frontier in electron microscopy is the development of in situ capabilities to observe reactions at atomic resolution in real time and within realistic environments. Here we present a new in situ gas cell holder that is designed for compatibility with a wide variety of sample type (i.e., dimpled 3-mm discs, standard mesh grids, various types of focused ion beam lamellae attached to half grids). Its capabilities include localized heating and precise control of the gas pressure and composition while simultaneously allowing atomic resolution imaging at ambient pressure. The results show that 0.25-nm lattice fringes are directly visible for nanoparticles imaged at ambient pressure with gas path lengths up to 20 μm. Additionally, we quantitatively demonstrate that while the attainable contrast and resolution decrease with increasing pressure and gas path length, resolutions better than 0.2 nm should be accessible at ambient pressure with gas path lengths less than the 15 μm utilized for these experiments.
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Affiliation(s)
- Shareghe Mehraeen
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA.
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46
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Watt J, Yu C, Chang SLY, Cheong S, Tilley RD. Shape Control from Thermodynamic Growth Conditions: The Case of hcp Ruthenium Hourglass Nanocrystals. J Am Chem Soc 2012; 135:606-9. [DOI: 10.1021/ja311366k] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- John Watt
- School of Chemical and Physical
Sciences and The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012,
New Zealand
| | - Chenlong Yu
- School of Chemical and Physical
Sciences and The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012,
New Zealand
| | - Shery L. Y. Chang
- Monash Centre
for Electron Microscopy, Monash University, Clayton, Australia
| | - Soshan Cheong
- School of Chemical and Physical
Sciences and The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012,
New Zealand
- Industrial Research Limited, P.O. Box 31-310, Lower Hutt 5040, New Zealand
| | - Richard D. Tilley
- School of Chemical and Physical
Sciences and The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012,
New Zealand
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47
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Van Tendeloo G, Bals S, Van Aert S, Verbeeck J, Van Dyck D. Advanced electron microscopy for advanced materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:5655-5675. [PMID: 22907862 DOI: 10.1002/adma.201202107] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Indexed: 06/01/2023]
Abstract
The idea of this Review is to introduce newly developed possibilities of advanced electron microscopy to the materials science community. Over the last decade, electron microscopy has evolved into a full analytical tool, able to provide atomic scale information on the position, nature, and even the valency atoms. This information is classically obtained in two dimensions (2D), but can now also be obtained in 3D. We show examples of applications in the field of nanoparticles and interfaces.
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48
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Goris B, Bals S, Van den Broek W, Carbó-Argibay E, Gómez-Graña S, Liz-Marzán LM, Van Tendeloo G. Atomic-scale determination of surface facets in gold nanorods. NATURE MATERIALS 2012; 11:930-5. [PMID: 23085569 DOI: 10.1038/nmat3462] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 09/17/2012] [Indexed: 05/19/2023]
Abstract
It is widely accepted that the physical properties of nanostructures depend on the type of surface facets. For Au nanorods, the surface facets have a major influence on crucial effects such as reactivity and ligand adsorption and there has been controversy regarding facet indexing. Aberration-corrected electron microscopy is the ideal technique to study the atomic structure of nanomaterials. However, these images correspond to two-dimensional (2D) projections of 3D nano-objects, leading to an incomplete characterization. Recently, much progress was achieved in the field of atomic-resolution electron tomography, but it is still far from being a routinely used technique. Here we propose a methodology to measure the 3D atomic structure of free-standing nanoparticles, which we apply to characterize the surface facets of Au nanorods. This methodology is applicable to a broad range of nanocrystals, leading to unique insights concerning the connection between the structure and properties of nanostructures.
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Affiliation(s)
- Bart Goris
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
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49
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Kwon SG, Krylova G, Sumer A, Schwartz MM, Bunel EE, Marshall CL, Chattopadhyay S, Lee B, Jellinek J, Shevchenko EV. Capping ligands as selectivity switchers in hydrogenation reactions. NANO LETTERS 2012; 12:5382-8. [PMID: 22988832 DOI: 10.1021/nl3027636] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We systematically investigated the role of surface modification of nanoparticles catalyst in alkyne hydrogenation reactions and proposed the general explanation of effect of surface ligands on the selectivity and activity of Pt and Co/Pt nanoparticles (NPs) using experimental and computational approaches. We show that the proper balance between adsorption energetics of alkenes at the surface of NPs as compared to that of capping ligands defines the selectivity of the nanocatalyst for alkene in alkyne hydrogenation reaction. We report that addition of primary alkylamines to Pt and CoPt(3) NPs can drastically increase selectivity for alkene from 0 to more than 90% with ~99.9% conversion. Increasing the primary alkylamine coverage on the NP surface leads to the decrease in the binding energy of octenes and eventual competition between octene and primary alkylamines for adsorption sites. At sufficiently high coverage of catalysts with primary alkylamine, the alkylamines win, which prevents further hydrogenation of alkenes into alkanes. Primary amines with different lengths of carbon chains have similar adsorption energies at the surface of catalysts and, consequently, the same effect on selectivity. When the adsorption energy of capping ligands at the catalytic surface is lower than adsorption energy of alkenes, the ligands do not affect the selectivity of hydrogenation of alkyne to alkene. On the other hand, capping ligands with adsorption energies at the catalytic surface higher than that of alkyne reduce its activity resulting in low conversion of alkynes.
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Affiliation(s)
- Soon Gu Kwon
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA
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50
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Nanostructural Studies of Fresh and Road-Aged Practical Pt/SiO2and Pt-Pd/Al2O3Diesel Oxidation Catalysts by using Aberration-Corrected (Scanning) Transmission Electron Microscopy. ChemCatChem 2012. [DOI: 10.1002/cctc.201200333] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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