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da Mota AF, Sadafi MM, Mosallaei H. Asymmetric imaging through engineered Janus particle obscurants using a Monte Carlo approach for highly asymmetric scattering media. Sci Rep 2024; 14:3850. [PMID: 38360866 PMCID: PMC10869813 DOI: 10.1038/s41598-024-54035-7] [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: 11/07/2023] [Accepted: 02/07/2024] [Indexed: 02/17/2024] Open
Abstract
The advancement of imaging systems has significantly ameliorated various technologies, including Intelligence Surveillance Reconnaissance Systems and Guidance Systems, by enhancing target detection, recognition, identification, positioning, and tracking capabilities. These systems can be countered by deploying obscurants like smoke, dust, or fog to hinder visibility and communication. However, these counter-systems affect the visibility of both sides of the cloud. In this sense, this manuscript introduces a new concept of a smoke cloud composed of engineered Janus particles to conceal the target image on one side while providing clear vision from the other. The proposed method exploits the unique scattering properties of Janus particles, which selectively interact with photons from different directions to open up the possibility of asymmetric imaging. This approach employs a model that combines a genetic algorithm with Discrete Dipole Approximation to optimize the Janus particles' geometrical parameters for the desired scattering properties. Moreover, we propose a Monte Carlo-based approach to calculate the image formed as photons pass through the cloud, considering highly asymmetric particles, such as Janus particles. The effectiveness of the cloud in disguising a target is evaluated by calculating the Probability of Detection (PD) and the Probability of Identification (PID) based on the constructed image. The optimized Janus particles can produce a cloud where it is possible to identify a target more than 50% of the time from one side (PID > 50%) while the target is not detected more than 50% of the time from the other side (PD < 50%). The results demonstrate that the Janus particle-engineered smoke enables asymmetric imaging with simultaneous concealment from one side and clear visualization from the other. This research opens intriguing possibilities for modern obscurant design and imaging systems through highly asymmetric and inhomogeneous particles besides target detection and identification capabilities in challenging environments.
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Affiliation(s)
- Achiles F da Mota
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, 02115, USA
- Department of Electrical Engineering, University of Brasília (UnB), Brasília, 70910-900, Brazil
| | - Mohammad Mojtaba Sadafi
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, 02115, USA
| | - Hossein Mosallaei
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, 02115, USA.
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2
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Gromoff Q, Benzo P, Saidi WA, Andolina CM, Casanove MJ, Hungria T, Barre S, Benoit M, Lam J. Exploring the formation of gold/silver nanoalloys with gas-phase synthesis and machine-learning assisted simulations. NANOSCALE 2023; 16:384-393. [PMID: 38063839 DOI: 10.1039/d3nr04471h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
While nanoalloys are of paramount scientific and practical interest, the main processes leading to their formation are still poorly understood. Key structural features in the alloy systems, including the crystal phase, chemical ordering, and morphology, are challenging to control at the nanoscale, making it difficult to extend their use to industrial applications. In this contribution, we focus on the gold/silver system that has two of the most prevalent noble metals and combine experiments with simulations to uncover the formation mechanisms at the atomic level. Nanoparticles were produced using a state-of-the-art inert-gas aggregation source and analyzed using transmission electron microscopy and energy-dispersive X-ray spectroscopy. Machine-learning-assisted molecular dynamics simulations were employed to model the crystallization process from liquid droplets to nanocrystals. Our study finds a preponderance of nanoparticles with five-fold symmetric morphology, including icosahedra and decahedra which is consistent with previous results on mono-metallic nanoparticles. However, we observed that gold atoms, rather than silver atoms, segregate at the surface of the obtained nanoparticles for all the considered alloy compositions. These segregation tendencies are in contrast to previous studies and have consequences on the crystallization dynamics and the subsequent crystal ordering. We finally showed that the underpinning of this surprising segregation dynamics is due to charge transfer and electrostatic interactions rather than surface energy considerations.
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Affiliation(s)
- Quentin Gromoff
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
| | - Patrizio Benzo
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
| | - Wissam A Saidi
- National Energy Technology Laboratory, United States Department of Energy, Pittsburgh, PA 15236, USA
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Christopher M Andolina
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Marie-José Casanove
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
| | - Teresa Hungria
- Centre de MicroCaractérisation Raimond Castaing, Université de Toulouse, 3 rue Caroline Aigle, F-31400 Toulouse, France
| | - Sophie Barre
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
| | - Magali Benoit
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
| | - Julien Lam
- CEMES, CNRS and Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France
- Univ. Lille, CNRS, INRA, ENSCL, UMR 8207, UMET, Unité Matériaux et Transformations, F 59000 Lille, France.
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3
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Petallidou KC, Ternero P, Messing ME, Schmidt-Ott A, Biskos G. Tuning atomic-scale mixing of nanoparticles produced by atmospheric-pressure spark ablation. NANOSCALE ADVANCES 2023; 5:6880-6886. [PMID: 38059023 PMCID: PMC10697000 DOI: 10.1039/d3na00152k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 08/21/2023] [Indexed: 12/08/2023]
Abstract
Nanoparticles (NPs) mixed at the atomic scale have been synthesized by atmospheric-pressure spark ablation using pairs of Pd and Hf electrodes. Gravimetric analysis of the electrodes showed that the fraction of each material in the resulting mixed NPs can be varied from ca. 15-85 at% to 85-15 at% by employing different combinations of electrode polarities and thicknesses. These results were also qualitatively corroborated by microscopy and elemental analysis of the produced NPs. When using pairs of electrodes having the same diameter, the material from the one at negative polarity was represented at a substantially higher fraction in the mixed NPs regardless of whether a pair of thin or thick electrodes were employed. This can be attributed to the higher ablation rate of the electrodes at the negative polarity, as already known from earlier experiments. When using electrodes of different diameters, the fraction of the element from the thinner electrode was always higher. This is because thinner electrodes are ablated more effectively due to, at least in part, the increased importance of the associated heat losses compared to its thicker counterpart. In those cases, the polarity of the electrodes had a significantly smaller effect. Overall, our results demonstrate, for the first time, that spark ablation can be used to control atomic scale mixing and thus produce alloyed NPs with compositions that can be tuned to a good extent by simply using different combinations of electrode diameters and polarities. This expands the capabilities of the technique for producing mixed nanoparticle building blocks of well-defined composition that are highly desired for a wide range of applications.
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Affiliation(s)
- Klito C Petallidou
- Climate and Atmosphere Research Centre, The Cyprus Institute 2121 Nicosia Cyprus
| | - Pau Ternero
- Department of Physics and NanoLund, Lund University 22100 Lund Sweden
| | - Maria E Messing
- Department of Physics and NanoLund, Lund University 22100 Lund Sweden
| | - Andreas Schmidt-Ott
- Climate and Atmosphere Research Centre, The Cyprus Institute 2121 Nicosia Cyprus
- Chemical Engineering, Delft University 2629 HZ Delft The Netherlands
| | - George Biskos
- Climate and Atmosphere Research Centre, The Cyprus Institute 2121 Nicosia Cyprus
- Faculty of Civil Engineering and Geosciences, Delft University of Technology 2628 CN Delft The Netherlands
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4
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Kohut A, Villy LP, Kohut G, Galbács G, Geretovszky Z. A Calibration-Free Optical Emission Spectroscopic Method to Determine the Composition of a Spark Discharge Plasma Used for AuAg Binary Nanoparticle Synthesis. APPLIED SPECTROSCOPY 2023; 77:1401-1410. [PMID: 37899740 DOI: 10.1177/00037028231207358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Spark discharge generators (SDGs) employ controlled gaseous environments to induce spark ablation of non-insulating electrodes, resulting in the formation of various nanostructures in the gas phase. The method offers technological advantages such as continuous particle production, scalable yield, and minimal waste. Additionally, the versatility of the process enables the generation of alloy nanoparticles from various material combinations, including immiscible ones. In order to fully exploit its potential, understanding the atomic mixing process during electrode ablation, particularly in the case of dissimilar electrodes, is crucial. Temporally and spatially resolved optical emission spectroscopy (OES) has been previously demonstrated as an effective characterization tool for spark plasmas in SDGs. However, to gain a deeper insight into the vapor mixing process, it is essential to quantitatively determine the plasma composition in both space and time. This paper introduces a calibration-free OES-based method tailored for spark plasmas utilized in binary nanoparticle generation. The method introduces the so-called multi-element combinatory Boltzmann plots, which use intensity ratios of emission atomic lines from different materials, allowing for the direct estimation of total number concentration ratios. The approach is tested using synthetic spectra and validated with experimental spark spectra obtained near an alloyed gold-silver (AuAg) electrode with a known composition. The study demonstrates the capabilities and robustness of the proposed method, with a focus on the AuAg system due to its significance in plasmonic research and frequent synthesis using spark ablation.
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Affiliation(s)
- Attila Kohut
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Lajos Péter Villy
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | | | - Gábor Galbács
- Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Zsolt Geretovszky
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
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5
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Musa I, Qamhieh N, Mahmoud ST. Ag Nanocluster Production through DC Magnetron Sputtering and Inert Gas Condensation: A Study of Structural, Kelvin Probe Force Microscopy, and Optical Properties. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2758. [PMID: 37887909 PMCID: PMC10609199 DOI: 10.3390/nano13202758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/06/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023]
Abstract
Silver nanoclusters are valuable for a variety of applications. A combination of direct current (DC) magnetron sputtering and inert gas condensation methods, employed within an ultra-high vacuum (UHV) system, was used to generate Ag nanoclusters with an average size of 4 nm. Various analytical techniques, including Scanning Probe Microscopy (SPM), X-ray Diffraction (XRD), Kelvin Probe Force Microscopy (KPFM), UV-visible absorption, and Photoluminescence, were employed to characterize the produced Ag nanoclusters. AFM topographic imaging revealed spherical nanoparticles with sizes ranging from 3 to 6 nm, corroborating data from a quadrupole mass filter (QMF). The XRD analysis verified the simple cubic structure of the Ag nanoclusters. The surface potential was assessed using KPFM, from which the work function was calculated with a reference highly ordered pyrolytic graphite (HOPG). The UV-visible absorption spectra displayed peaks within the 350-750 nm wavelength range, with a strong absorption feature at 475 nm. Additionally, lower excitation wavelengths resulted in a sharp peak emission at 370 nm, which became weaker and broader when higher excitation wavelengths were used.
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Affiliation(s)
- Ishaq Musa
- Department of Physics, Palestine Technical University-Kadoorie, Tulkarem P.O. Box 7, Palestine
| | - Naser Qamhieh
- Department of Physics, UAE University, Al-Ain P.O. Box 15551, United Arab Emirates;
| | - Saleh T. Mahmoud
- Department of Physics, UAE University, Al-Ain P.O. Box 15551, United Arab Emirates;
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6
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Lizunova AA, Borisov VI, Malo D, Musaev AG, Kameneva EI, Efimov AA, Volkov IA, Buchnev AI, Shuklov IA, Ivanov VV. Spark Discharge Synthesis and Characterization of Ge/Sn Janus Nanoparticles. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101701. [PMID: 37242117 DOI: 10.3390/nano13101701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/17/2023] [Accepted: 05/20/2023] [Indexed: 05/28/2023]
Abstract
Germanium-tin nanoparticles are promising materials for near- and mid-infrared photonics thanks to their tunable optical properties and compatibility with silicon technology. This work proposes modifying the spark discharge method to produce Ge/Sn aerosol nanoparticles during the simultaneous erosion of germanium and tin electrodes. Since tin and germanium have a significant difference in the potential for electrical erosion, an electrical circuit damped for one period was developed to ensure the synthesis of Ge/Sn nanoparticles consisting of independent germanium and tin crystals of different sizes, with the ratio of the atomic fraction of tin to germanium varying from 0.08 ± 0.03 to 0.24 ± 0.07. We investigated the elemental and phase composition, size, morphology, and Raman and absorbance spectra of the nanoparticles synthesized under different inter-electrode gap voltages and the presence of additional thermal treatment directly in a gas flow at 750 °C. The research shows that the in-flow thermal treatment of aerosol-agglomerated nanoparticles produced special individual bicrystalline Janus Ge/Sn nanoparticles with an average size of 27 nm and a decreasing absorption function with a changing slope at 700 nm.
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Affiliation(s)
- Anna A Lizunova
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | | | - Dana Malo
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
- Biomedical Engineering Department, Faculty of Mechanical and Electrical Engineering, Damascus University, Damascus P.O. Box 30621, Syria
| | - Andrey G Musaev
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | | | - Alexey A Efimov
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Ivan A Volkov
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Arseny I Buchnev
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Ivan A Shuklov
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Victor V Ivanov
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
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7
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Seifner MS, Hu T, Snellman M, Jacobsson D, Deppert K, Messing ME, Dick KA. Insights into the Synthesis Mechanisms of Ag-Cu 3P-GaP Multicomponent Nanoparticles. ACS NANO 2023; 17:7674-7684. [PMID: 37017472 PMCID: PMC10134500 DOI: 10.1021/acsnano.3c00140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/03/2023] [Indexed: 06/19/2023]
Abstract
Metal-semiconductor nanoparticle heterostructures are exciting materials for photocatalytic applications. Phase and facet engineering are critical for designing highly efficient catalysts. Therefore, understanding processes occurring during the nanostructure synthesis is crucial to gain control over properties such as the surface and interface facets' orientations, morphology, and crystal structure. However, the characterization of nanostructures after the synthesis makes clarifying their formation mechanisms nontrivial and sometimes even impossible. In this study, we used an environmental transmission electron microscope with an integrated metal-organic chemical vapor deposition system to enlighten fundamental dynamic processes during the Ag-Cu3P-GaP nanoparticle synthesis using Ag-Cu3P seed particles. Our results reveal that the GaP phase nucleated at the Cu3P surface, and growth proceeded via a topotactic reaction involving counter-diffusion of Cu+ and Ga3+ cations. After the initial GaP growth steps, the Ag and Cu3P phases formed specific interfaces with the GaP growth front. GaP growth proceeded by a similar mechanism observed for the nucleation involving the diffusion of Cu atoms through/along the Ag phase toward other regions, followed by the redeposition of Cu3P at a specific Cu3P crystal facet, not in contact with the GaP phase. The Ag phase was essential for this process by acting as a medium enabling the efficient transport of Cu atoms away from and, simultaneously, Ga atoms toward the GaP-Cu3P interface. This study shows that enlightening fundamental processes is critical for progress in synthesizing phase- and facet-engineered multicomponent nanoparticles with tailored properties for specific applications, including catalysis.
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Affiliation(s)
- Michael S. Seifner
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
| | - Tianyi Hu
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
| | - Markus Snellman
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Daniel Jacobsson
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
- National
Center for High Resolution Electron Microscopy, Lund University, Box 124, 22100 Lund, Sweden
| | - Knut Deppert
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Maria E. Messing
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Kimberly A. Dick
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box
118, 22100 Lund, Sweden
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8
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Zhang Y, He J, Tong J, Lai H, Liang P, Huang Z, Ta S, Lin T, Yang G, Cui C. Elucidation of the capillarity-promoted sintering of silver nanoparticles produced by a spark ablation vapor source. ADV POWDER TECHNOL 2023. [DOI: 10.1016/j.apt.2023.103972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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9
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Tamadate T, Yang S, Hogan CJ. A neural network parametrized coagulation rate model for <3 nm titanium dioxide nanoclusters. J Chem Phys 2023; 158:084301. [PMID: 36859082 DOI: 10.1063/5.0136592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Coagulation is a key factor governing the size distribution of nanoclusters during the high temperature synthesis of metal oxide nanomaterials. Population balance models are strongly influenced by the coagulation rate coefficient utilized. Although simplified coagulation models are often invoked, the coagulation process, particularly for nanoscale particles, is complex, affected by the coagulating nanocluster sizes, the surrounding temperature, and potential interactions. Toward developing improved models of nanocluster and nanoparticle growth, we have developed a neural network (NN) model to describe titanium dioxide (TiO2) nanocluster coagulation rate coefficients, trained with molecular dynamics (MD) trajectory calculations. Specifically, we first calculated TiO2 nanocluster coagulation probabilities via MD trajectory calculations varying the nanocluster diameters from 0.6 to 3.0 nm, initial relative velocity from 20 to 700 m s-1, and impact parameter from 0.0 to 8.0 nm. Calculations consider dipole-dipole interactions, dispersion interactions, and short-range repulsive interactions. We trained a NN model to predict whether a given set of nanocluster diameters, impact parameter, and initial velocity would lead to the outcome of coagulation. The accuracy between the predicted outcomes from the NN model and the MD trajectory calculation results is >95%. We subsequently utilized both the NN model and MD trajectory calculations to examine coagulation rate coefficients at 300 and 1000 K. The NN model predictions are largely within the range 0.65-1.54 of MD predictions, and importantly NN predictions capture the local minimum coagulation rate coefficients observed in MD trajectory calculations. The NN model can be directly implemented in population balances of TiO2 formation.
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Affiliation(s)
- Tomoya Tamadate
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Suo Yang
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Christopher J Hogan
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
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10
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Nelli D, El Koraychy EY, Cerbelaud M, Crespin B, Videcoq A, Giacomello A, Ferrando R. Two-Steps Versus One-Step Solidification Pathways of Binary Metallic Nanodroplets. ACS NANO 2023; 17:587-596. [PMID: 36537367 PMCID: PMC9836354 DOI: 10.1021/acsnano.2c09741] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
The solidification of AgCo, AgNi, and AgCu nanodroplets is studied by molecular dynamics simulations in the size range of 2-8 nm. All these systems tend to phase separate in the bulk solid with surface segregation of Ag. Despite these similarities, the simulations reveal clear differences in the solidification pathways. AgCo and AgNi already separate in the liquid phase, and they solidify in configurations close to equilibrium. They can show a two-step solidification process in which Co-/Ni-rich parts solidify at higher temperatures than the Ag-rich part. AgCu does not separate in the liquid and solidifies in one step, thereby remaining in a kinetically trapped state down to room temperature. The solidification mechanisms and the size dependence of the solidification temperatures are analyzed, finding qualitatively different behaviors in AgCo/AgNi compared to AgCu. These differences are rationalized by an analytical model.
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Affiliation(s)
- Diana Nelli
- Dipartimento
di Fisica, Università di Genova, Via Dodecaneso 33, 16146Genova, Italia
| | - El Yakout El Koraychy
- Dipartimento
di Fisica, Università di Genova, Via Dodecaneso 33, 16146Genova, Italia
| | | | - Benoit Crespin
- Université
de Limoges, CNRS, XLIM/ASALI, F-87000Limoges, France
| | - Arnaud Videcoq
- Université
de Limoges, CNRS, IRCER, UMR 7315, F-87000Limoges, France
| | - Alberto Giacomello
- Dipartimento
di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, via Eudossiana 18, 00184Roma, Italia
| | - Riccardo Ferrando
- Dipartimento
di Fisica, Università di Genova, Via Dodecaneso 33, 16146Genova, Italia
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11
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Villy LP, Kohut A, Kéri A, Bélteki Á, Radnóczi G, Fogarassy Z, Radnóczi GZ, Galbács G, Geretovszky Z. Continuous spark plasma synthesis of Au/Co binary nanoparticles with tunable properties. Sci Rep 2022; 12:18560. [PMCID: PMC9633648 DOI: 10.1038/s41598-022-22928-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
AbstractWe present here a scalable and environmentally friendly gas phase technique employing atmospheric pressure electrical spark discharge plasmas for the production of Au/Co binaries, an effective catalyst system for the decomposition of hydrogen-rich compounds, such as ammonium borane. We demonstrate that Au/Co alloy nanoparticles can be produced via the spark plasma-based technique. The possibility of varying the morphology and phase structure via real time heat treatment of the generated aerosol to form Au/Co/CoO particles with continuous control over a wide particle compositional range (from 24 to 64 at.% [Co]/([Co] + [Au]) content) is also demonstrated. Since our spark-based approach is proven to be capable of providing reasonable particle yields, these results may contribute to the transition of lab-scale, nanocatalyst-based hydrogen storage systems to real world applications.
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12
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López-Martín R, Rodrigo I, Ballesta C, Arias A, Mas A, Santos Burgos B, Normile PS, De Toro JA, Binns C. Effectiveness of Silver Nanoparticles Deposited in Facemask Material for Neutralising Viruses. NANOMATERIALS 2022; 12:nano12152662. [PMID: 35957092 PMCID: PMC9370635 DOI: 10.3390/nano12152662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/20/2022] [Accepted: 07/25/2022] [Indexed: 01/23/2023]
Abstract
Cloth used for facemask material has been coated with silver nanoparticles using an aerosol method that passes pure uncoated nanoparticles through the cloth and deposits them throughout the volume. The particles have been characterized by electron microscopy and have a typical diameter of 4 nm with the atomic structure of pure metallic silver presented as an assortment of single crystals and polycrystals. The particles adhere well to the cloth fibers, and the coating consists of individual nanoparticles at low deposition times, evolving to fully agglomerated assemblies in heavy coatings. The cloth was exposed to Usutu virus and murine norovirus particles in suspension and allowed to dry, following which, the infectious virus particles were rescued by soaking the cloth in culture media. It was found that up to 98% of the virus particles were neutralized by this contact with the silver nanoparticles for optimum deposition conditions. The best performance was obtained with agglomerated films and with polycrystalline nanoparticles. The work indicates that silver nanoparticles embedded in masks can neutralize the majority of virus particles that enter the mask and thus increase the opacity of masks to infectious viruses by up to a factor of 50. In addition, the majority of the virus particles released from the mask after use are non-infectious.
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Affiliation(s)
- Raúl López-Martín
- Instituto Regional de Investigación Científica Aplicada (IRICA), 13005 Ciudad Real, Spain; (R.L.-M.); (B.S.B.); (P.S.N.); (J.A.D.T.)
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Imanol Rodrigo
- Unidad de Biomedicina, CSIC, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (I.R.); (C.B.); (A.A.); (A.M.)
- Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, 02008 Albacete, Spain
| | - Carlos Ballesta
- Unidad de Biomedicina, CSIC, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (I.R.); (C.B.); (A.A.); (A.M.)
- Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, 02008 Albacete, Spain
| | - Armando Arias
- Unidad de Biomedicina, CSIC, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (I.R.); (C.B.); (A.A.); (A.M.)
- Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, 02008 Albacete, Spain
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
| | - Antonio Mas
- Unidad de Biomedicina, CSIC, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (I.R.); (C.B.); (A.A.); (A.M.)
- Unidad de Medicina Molecular, Centro Regional de Investigaciones Biomédicas (CRIB), Universidad de Castilla-La Mancha, 02008 Albacete, Spain
- Facultad de Farmacia, Universidad de Castilla-La Mancha, 02071 Albacete, Spain
| | - Benito Santos Burgos
- Instituto Regional de Investigación Científica Aplicada (IRICA), 13005 Ciudad Real, Spain; (R.L.-M.); (B.S.B.); (P.S.N.); (J.A.D.T.)
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Peter S. Normile
- Instituto Regional de Investigación Científica Aplicada (IRICA), 13005 Ciudad Real, Spain; (R.L.-M.); (B.S.B.); (P.S.N.); (J.A.D.T.)
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Jose A. De Toro
- Instituto Regional de Investigación Científica Aplicada (IRICA), 13005 Ciudad Real, Spain; (R.L.-M.); (B.S.B.); (P.S.N.); (J.A.D.T.)
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Chris Binns
- Instituto Regional de Investigación Científica Aplicada (IRICA), 13005 Ciudad Real, Spain; (R.L.-M.); (B.S.B.); (P.S.N.); (J.A.D.T.)
- Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
- Correspondence:
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13
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Seifner MS, Snellman M, Makgae OA, Kumar K, Jacobsson D, Ek M, Deppert K, Messing ME, Dick KA. Interface Dynamics in Ag-Cu 3P Nanoparticle Heterostructures. J Am Chem Soc 2022; 144:248-258. [PMID: 34949090 PMCID: PMC8759066 DOI: 10.1021/jacs.1c09179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Indexed: 12/17/2022]
Abstract
Earth-abundant transition metal phosphides are promising materials for energy-related applications. Specifically, copper(I) phosphide is such a material and shows excellent photocatalytic activity. Currently, there are substantial research efforts to synthesize well-defined metal-semiconductor nanoparticle heterostructures to enhance the photocatalytic performance by an efficient separation of charge carriers. The involved crystal facets and heterointerfaces have a major impact on the efficiency of a heterostructured photocatalyst, which points out the importance of synthesizing potential photocatalysts in a controlled manner and characterizing their structural and morphological properties in detail. In this study, we investigated the interface dynamics occurring around the synthesis of Ag-Cu3P nanoparticle heterostructures by a chemical reaction between Ag-Cu nanoparticle heterostructures and phosphine in an environmental transmission electron microscope. The major product of the Cu-Cu3P phase transformation using Ag-Cu nanoparticle heterostructures with a defined interface as a template preserved the initially present Ag{111} facet of the heterointerface. After the complete transformation, corner truncation of the faceted Cu3P phase led to a physical transformation of the nanoparticle heterostructure. In some cases, the structural rearrangement toward an energetically more favorable heterointerface has been observed and analyzed in detail at the atomic level. The herein-reported results will help better understand dynamic processes in Ag-Cu3P nanoparticle heterostructures and enable facet-engineered surface and heterointerface design to tailor their physical properties.
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Affiliation(s)
- Michael S. Seifner
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
| | - Markus Snellman
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Ofentse A. Makgae
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
| | - Krishna Kumar
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
| | - Daniel Jacobsson
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
- National
Center for High Resolution Electron Microscopy, Lund University, Box 124, 22100 Lund, Sweden
| | - Martin Ek
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
| | - Knut Deppert
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Maria E. Messing
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
- Solid
State Physics, Lund University, Box 118, 22100 Lund, Sweden
| | - Kimberly A. Dick
- Centre
for Analysis and Synthesis, Lund University, Box 124, 22100 Lund, Sweden
- NanoLund, Lund University, Box 118, 22100 Lund, Sweden
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14
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Settem M, Srivastav AK, Kanjarla AK. Understanding the strain-dependent structure of Cu nanocrystals in Ag-Cu nanoalloys. Phys Chem Chem Phys 2021; 23:26165-26177. [PMID: 34797355 DOI: 10.1039/d1cp04145b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The structure of octahedral Ag-Cu nanoalloys is investigated by means of basin hopping Monte Carlo (BHMC) searches involving the optimization of shape and chemical ordering. Due to the significant size mismatch between Ag and Cu, the misfit strain plays a key role in determining the structure of Ag-Cu nanoalloys. At all the compositions, segregated chemical ordering is observed. However, the shape of the Cu nanocrystal and the associated defects are significantly different. At lower amounts of Cu (as little as 2 atom %), defects close to the surface are observed leading to a highly non-compact shape of the Cu nanocrystal which is non-trivial. The number of Cu-Cu bonds is relatively lower in the non-compact shape which is contrary to the preference of bulk Ag-Cu alloys to maximize the homo-atomic bonds. Due to the non-compact shape, {100} Ag-Cu interfaces are observed which are not expected. As the amount of Cu increases, the Cu nanocrystal undergoes a shape transition from non-compact to a compact octahedron. The associated defect structure is also modified. The structural changes due to the strain effects have been explained by calculating the atomic pressure maps and the bond length distributions. The trends relating to the structure have also been verified at larger sizes.
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Affiliation(s)
- Manoj Settem
- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - Ajeet K Srivastav
- Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology, Nagpur, 440010, India
| | - Anand K Kanjarla
- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, 600036, India. .,Ceramic Technologies Group - Center of Excellence in Materials and Manufacturing for Futuristic Mobility, Indian Institute of Technology Madras, Chennai, 600036, India
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15
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Nelli D, Pietrucci F, Ferrando R. Impurity diffusion in magic-size icosahedral clusters. J Chem Phys 2021; 155:144304. [PMID: 34654289 DOI: 10.1063/5.0060236] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Atomic diffusion is at the basis of chemical ordering transformations in nanoalloys. Understanding the diffusion mechanisms at the atomic level is therefore a key issue in the study of the thermodynamic behavior of these systems and, in particular, of their evolution from out-of-equilibrium chemical ordering types often obtained in the experiments. Here, the diffusion is studied in the case of a single-atom impurity of Ag or Au moving within otherwise pure magic-size icosahedral clusters of Cu or Co by means of two different computational techniques, i.e., molecular dynamics and metadynamics. Our simulations reveal unexpected diffusion pathways, in which the displacement of the impurity is coupled with the creation of vacancies in the central part of the cluster. We show that the observed mechanism is quite different from the vacancy-mediated diffusion processes identified so far, and we demonstrate that it can be related to the presence of non-homogeneous compressive stress in the inner part of the icosahedral structure.
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Affiliation(s)
- Diana Nelli
- Dipartimento di Fisica dell'Università di Genova, via Dodecaneso 33, Genova 16146, Italy
| | - Fabio Pietrucci
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IMPMC, 75005 Paris, France
| | - Riccardo Ferrando
- Dipartimento di Fisica dell'Università di Genova and CNR-IMEM, via Dodecaneso 33, Genova 16146, Italy
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