Articles de revues : « Plasmonic Nanoparticles(Au, Ag) »

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Yeshchenko, O. A., A. O. Bartenev, A. P. Naumenko, N. V. Kutsevol, Iu I. Harahuts et A. I. Marinin. « Laser-Driven Aggregation in Dextran–Graft–PNIPAM/Silver Nanoparticles Hybrid Nanosystem : Plasmonic Effects ». Ukrainian Journal of Physics 65, n^o 3 (26 mars 2020) : 254. http://dx.doi.org/10.15407/ujpe65.3.254.

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The laser-induced aggregation in the thermosensitive dextran grafted-poly(N-isopropylacrylamide) copolymer/Ag nanoparticles (D–g–PNIPAM/AgNPs) hybrid nanosystem in water has been observed. The laser-induced plasmonic heating of Ag NPs causes the Lower Critical Solution Temperature (LCST) conformation transition in D–g–PNIPAM/AgNPs macromolecules which shrink during the transition. The shrinking decreases sharply the distance between the silver nanoparticles that launches the aggregation of Ag NPs and the appearance of plasmonic attractive optical forces acting between the nanoparticles. It has been shown that the approach of the laser wavelength to the surface plasmon resonance in Ag nanoparticles leads to a significant strengthening of the observed aggregation, which proves its plasmon nature. The laser-induced transformations in the D–g–PNIPAM/AgNPs nanosystem have been found to be essentially irreversible that differs principally them from the temperature-induced transformations. Such fundamental difference proves the crucial role of the optical forces arising due to the excitation of surface plasmons in Ag NPs.

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Wang, Jing, Kai-Xuan Fei, Xin Yang, Shuai-Shuai Zhang et Yin-Xian Peng. « Synthesis and Plasmonic Chiroptical Studies of Sodium Deoxycholate Modified Silver Nanoparticles ». Materials 11, n^o 8 (26 juillet 2018) : 1291. http://dx.doi.org/10.3390/ma11081291.

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Sodium deoxycholate modified silver nanoparticles prepared in the presence of sodium deoxycholate as a chiral inducer exhibit plasmonic circular dichroism (CD) signals. The plasmon-induced chirality arises from the presence of chiral molecules (sodium deoxycholate) on the surface of Ag nanoparticles, which transfer their chiral properties to the visible wavelength range due to the Coulomb interactions between the chiral molecules and plasmonic nanoparticles. The prepared Ag nanoparticles (NPs) exhibit distinct line shapes of plasmonic CD, which can be tailored by varying the pH values of the solutions. A mechanism was proposed to explain the generation of the distinct plasmonic CD shapes, which indicated that the arrangements of chiral molecules in the plasmonic hot spots between Ag NPs are crucial for the induced plasmonic CD.

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Sotiriou, Georgios A., Gion Diego Etterlin, Anastasia Spyrogianni, Frank Krumeich, Jean-Christophe Leroux et Sotiris E. Pratsinis. « Plasmonic biocompatible silver–gold alloyed nanoparticles ». Chem. Commun. 50, n^o 88 (2014) : 13559–62. http://dx.doi.org/10.1039/c4cc05297h.

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Sun, Chunlei, Caiyan Qin, Han Zhai, Bin Zhang et Xiaohu Wu. « Optical Properties of Plasma Dimer Nanoparticles for Solar Energy Absorption ». Nanomaterials 11, n^o 10 (15 octobre 2021) : 2722. http://dx.doi.org/10.3390/nano11102722.

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Plasmonic nanofluids have excellent optical properties in solar energy absorption and have been widely studied in solar thermal conversion technology. The absorption of the visible region of solar energy by ordinary metal nanoparticles is usually limited to a narrow resonance band, so it is necessary to enhance the coupling effect of nanoparticles in the visible spectrum region to improve absorption efficiency. However, it is still a difficult task to improve solar energy absorption by adjusting the structure and performance of nanoparticles. In this paper, a plasma dimer Ag nanoparticle is proposed to excite localized surface plasmon resonance (LSPR). Compared with an ordinary Ag nanoparticle in the visible region, the plasmonic Ag dimer nanoparticle produces more absorption peaks and broader absorption bands, which can broaden solar energy absorption. By analyzing the electromagnetic field of the nanoparticle, the resonance mode of the plasma dimer is discussed. The effects of the geometric dimensions of the nanoparticle and the embedding of two spheres on the optical properties are studied. In addition, the effects of a trimer and its special structure on the optical properties are also analyzed. The results show that the proposed plasma dimer Ag nanoparticle has broad prospects for application in solar thermal conversion technology.

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Loiseau, Alexis, Victoire Asila, Gabriel Boitel-Aullen, Mylan Lam, Michèle Salmain et Souhir Boujday. « Silver-Based Plasmonic Nanoparticles for and Their Use in Biosensing ». Biosensors 9, n^o 2 (10 juin 2019) : 78. http://dx.doi.org/10.3390/bios9020078.

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The localized surface plasmon resonance (LSPR) property of metallic nanoparticles is widely exploited for chemical and biological sensing. Selective biosensing of molecules using functionalized nanoparticles has become a major research interdisciplinary area between chemistry, biology and material science. Noble metals, especially gold (Au) and silver (Ag) nanoparticles, exhibit unique and tunable plasmonic properties; the control over these metal nanostructures size and shape allows manipulating their LSPR and their response to the local environment. In this review, we will focus on Ag-based nanoparticles, a metal that has probably played the most important role in the development of the latest plasmonic applications, owing to its unique properties. We will first browse the methods for AgNPs synthesis allowing for controlled size, uniformity and shape. Ag-based biosensing is often performed with coated particles; therefore, in a second part, we will explore various coating strategies (organics, polymers, and inorganics) and their influence on coated-AgNPs properties. The third part will be devoted to the combination of gold and silver for plasmonic biosensing, in particular the use of mixed Ag and AuNPs, i.e., AgAu alloys or Ag-Au core@shell nanoparticles will be outlined. In the last part, selected examples of Ag and AgAu-based plasmonic biosensors will be presented.

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Kodanek, Torben, Axel Freytag, Anja Schlosser, Suraj Naskar, Thomas Härtling, Dirk Dorfs et Nadja Carola Bigall. « Macroscopic Aerogels with Retained Nanoscopic Plasmonic Properties ». Zeitschrift für Physikalische Chemie 232, n^o 9-11 (28 août 2018) : 1675–89. http://dx.doi.org/10.1515/zpch-2017-1045.

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Abstract Aerogels can bridge the nanoscopic to the macroscopic world. One physical phenomenon typically limited to the nanoscopic world is the occurrence of localized surface plasmon resonances (LSPRs), which are observed in conductive nanoparticles. Once brought into close contact, assemblies or superstructures of these nanoparticles often lose their plasmonic properties in the transition stage towards the bulk material. Therefore, LSPRs are typically not observed in macroscopic objects. The present work aims at voluminous nanoparticle-based aerogels with optical properties close to that of the initial colloidal solution and the possibility to manipulate the final plasmonic properties by bringing the particles into defined distances. In detail, Ag nanocrystals with silica shells ranging from 0 to 12 nm are employed as building blocks, which are assembled from their solution into macroscopic three-dimensional superstructures by freezing and subsequent lyophilization. These cryogelated aerogels are synthesized as monoliths and thin films in which the Ag nanocrystals are arranged in defined distances according to their silica shell. The resulting aerogels exhibit plasmonic properties ranging from a behavior similar to that of the building blocks for the thickest shell to a heavily distorted behavior for bare Ag nanocrystals.

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Hu, Yang, Chao Pan, Cai Xia Gao, Jun Fan et En Zhou Liu. « Photocatalytic Water Splitting over Ag/TiO₂ Nano-Wire Films ». Applied Mechanics and Materials 665 (octobre 2014) : 288–91. http://dx.doi.org/10.4028/www.scientific.net/amm.665.288.

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Plasmonic Ag decorated TiO2 nano-wire film was firstly prepared by the combination of a hydrothermal method and a microwave-assisted chemical reduction process. The results show that Ag deposited TiO2 film exhibits obvious visible light absorption due to surface plasmon resonance absorption of Ag nanoparticles. Besides, fluorescence quenching is observed in the composite film under the excitation of 250 nm. Photocatalytic tests show that Ag deposited TiO2 exhibits enhanced photocatalytic activity for H2 production by water splitting due to the synergistic effect between charge transfer and surface plasmon resonance absorption properties of Ag nanoparticles.

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Kuriakose, Sini, Vandana Choudhary, Biswarup Satpati et Satyabrata Mohapatra. « Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method ». Beilstein Journal of Nanotechnology 5 (15 mai 2014) : 639–50. http://dx.doi.org/10.3762/bjnano.5.75.

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We report the synthesis of Ag–ZnO hybrid plasmonic nanostructures with enhanced photocatalytic activity by a facile wet-chemical method. The structural, optical, plasmonic and photocatalytic properties of the Ag–ZnO hybrid nanostructures were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL) and UV–visible absorption spectroscopy. The effects of citrate concentration and Ag nanoparticle loading on the photocatalytic activity of Ag–ZnO hybrid nanostructures towards sun-light driven degradation of methylene blue (MB) have been investigated. Increase in citrate concentration has been found to result in the formation of nanodisk-like structures, due to citrate-assisted oriented attachment of ZnO nanoparticles. The decoration of ZnO nanostructures with Ag nanoparticles resulted in a significant enhancement of the photocatalytic degradation efficiency, which has been found to increase with the extent of Ag nanoparticle loading.

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Yazdani, Ahmad, Mahdi Ghazanfari et Fatemeh Johar. « Light trapping effect in plasmonic blockade at the interface of Fe3O4@Ag core/shell ». RSC Advances 5, n^o 51 (2015) : 40989–96. http://dx.doi.org/10.1039/c5ra06412k.

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Spherical isotropic Fe₃O₄nanoparticles were coated with Ag-shell in order to investigate the possibility of trapping photons through plasmon or plasmonic energy transfer at the magnetic–plasmonic interface coupling structure of core/shell.

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Kanapina, A. E. « FEATURES OF THE DECAY OF EXCITED STATES OF IONIC DYES IN THE NEAR FIELD OF METAL NANOPARTICLES ». Eurasian Physical Technical Journal 20, n^o 2 (44) (21 juin 2023) : 106–11. http://dx.doi.org/10.31489/2023no2/106-111.

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The influence factor of silver nanoparticles on the intramolecular processes of deactivation of the electronically excited state of polymethine dyes (PD) of different ionicity has been studied. It has been demonstrated that the optical density forcationic 1 and anionic 2 dyes does not change under the action of the plasmon field of Ag nanoparticles. Whereas an increase in absorbance by almost 18% was observed for neutral dye 3. A decrease in the enhancement in fluorescence intensity in the series of anionic–cationic–neutral dyes was registered upon addition of Ag nanoparticles to their solutions. The fluorescence lifetime practically does not change for all PDs under study.Data processing within the framework of the model of the influence of a plasmonic nanoparticle on radiative transitions in a dye molecule showed that the values of plasmon-enhanced rates of radiative decay of molecules decreases from neutral to cationic and, finally, to anionic dye. The rates of energy transfer from PD to plasmonic nanoparticles decrease in the reverse sequence of dyes, i.e. anionic-cationic-neutral PD. This is expressed in a decrease in the proportion of neutral dye molecules that were deactivated by fluorescence.

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Schiffmann, Alexander, Thomas Jauk, Daniel Knez, Harald Fitzek, Ferdinand Hofer, Florian Lackner et Wolfgang E. Ernst. « Helium droplet assisted synthesis of plasmonic Ag@ZnO core@shell nanoparticles ». Nano Research 13, n^o 11 (27 juillet 2020) : 2979–86. http://dx.doi.org/10.1007/s12274-020-2961-z.

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Abstract Plasmonic Ag@ZnO core@shell nanoparticles are formed by synthesis inside helium droplets with subsequent deposition and controlled oxidation. The particle size and shape can be controlled from spherical sub-10 nm particles to larger elongated structures. An advantage of the method is the complete absence of solvents, precursors, and other chemical agents. The obtained particle morphology and elemental composition have been analyzed by scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDS). The results reveal that the produced particles form a closed and homogeneous ZnO layer around a 2–3 nm Ag core with a uniform thickness of (1.33 ± 0.15) nm and (1.63 ± 0.31) nm for spherical and wire-like particles, respectively. The results are supported by ultraviolet photoelectron spectroscopy (UPS), which indicates a fully oxidized shell layer for the particles studied by STEM. The plasmonic properties of the produced spherical Ag@ZnO core@shell particles are investigated by two-photon photoelectron (2PPE) spectroscopy. Upon excitation of the localized surface plasmon resonance in Ag at around 3 eV, plasmonic enhancement leads to the liberation of electrons with high kinetic energy. This is observed for both Ag and Ag@ZnO particles, showing that even if a Ag cluster is covered by the ZnO layer, a plasmonic enhancement can be observed by photoelectron spectroscopy.

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Sharma, Himanshu, et R. Singhal. « SHI irradiation induced modifications of plasmonic properties of Ag-TiO2 thin film and study using FDTD simulation ». Materials Science-Poland 37, n^o 3 (1 septembre 2019) : 373–80. http://dx.doi.org/10.2478/msp-2019-0038.

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AbstractModifications in morphological and plasmonic properties of heavily doped Ag-TiO2 nanocomposite thin films by ion irradiation have been observed. The Ag-TiO2 nanocomposite thin films were synthesized by RF co-sputtering and irradiated by 90 MeV Ni ions with different fluences. The modifications in morphological, structural and plasmonic properties of the nanocomposite thin films caused by ion irradiation were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Vis absorption spectroscopy. The thickness of the film and concentration of Ag were assessed by Rutheford backscattering (RBS) as ~50 nm and 56 at.%, respectively. Interestingly, localized surface plasmon resonance (LSPR) appeared at 566 nm in the thin film irradiated at the fluence of 1 × 1013 ions/cm2. This plasmonic behavior can be attributed to the increment in interparticle separation. Increased interparticle separation diminishes the plasmonic coupling between the nanoparticles and the LSPR appears in the visible region. The distribution of Ag nanoparticles obtained from HR-TEM images has been used to simulate absorption spectra and electric field distribution along Ag nanoparticles with the help of FDTD (Finite Difference Time Domain). Further, the ion irradiation results (experimental as well simulated) were compared with the annealed nanocomposite thin film and it was found that optical properties of heavily doped metal in the metal oxide matrix can be more improved by ion irradiation in comparison with thermal annealing.

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Khurgin, Jacob B. « Pliable polaritons : Wannier exciton-plasmon coupling in metal-semiconductor structures ». Nanophotonics 8, n^o 4 (20 novembre 2018) : 629–39. http://dx.doi.org/10.1515/nanoph-2018-0166.

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AbstractPlasmonic structures are known to support the modes with sub-wavelength volumes in which the field/matter interactions are greatly enhanced. Coupling between the molecular excitations and plasmons leading to the formation of “plexcitons” has been investigated for a number of organic molecules. However, plasmon-exciton coupling in metal/semiconductor structures has not experienced the same degree of attention. In this work, we show that the “very strong coupling” regime in which the Rabi energy exceeds the exciton binding energy is attainable in semiconductor-cladded plasmonic nanoparticles and leads to the formation of Wannier exciton-plasmon polariton (WEPP), which is bound to the metal nanoparticle and characterized by dramatically smaller (by a factor of a few) excitonic radius and correspondingly higher ionization energy. This higher ionization energy, which exceeding approaches 100 meV for the CdS/Ag structures, may make room-temperature Bose-Einstein condensation and polariton lasing in plasmonic/semiconductor structures possible.

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Kumar, P. Naveen, Neena Bachan, V. Chandrakala, D. J. Sharmila, J. Sahaya Selva Mary, W. Jothi Jeyarani et J. Merline Shyla. « Relative Analysis of Plasmonic Impact of Silver and Aluminium Nanoparticles on SnO2 Nanoparticles for Photovoltaic Applications ». Advanced Science Letters 24, n^o 8 (1 août 2018) : 5661–65. http://dx.doi.org/10.1166/asl.2018.12171.

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The present study reports Ag and Al plasmon doped SnO2 nanoparticles synthesized by a facile sol–gel route for photovoltaic applications. The crystallite and particle size of the samples detected from X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM) studies depict that the Ag and Al doped SnO2 nanoparticles possessed declined sizes due to the effect of plasmons. Ultra Violet Diffuse Reflectance Spectroscopy (UV-DRS) technique deduced the optical behaviour of the samples enriched with Surface Plasmon Resonance effect in the doped SnO2 nanoparticles. Surface properties from Brunauer Emmett Teller (BET) studies revealed an enhancement of surface area in the Ag doped SnO2 nanoparticles. Field-dependent dark and photoconductivity studies of the samples revealed significant rise in the photo conducting nature of Ag and Al doped SnO2 nanoparticles. An overall relative analysis suggests that the Ag and Al plasmon doped SnO2 nanoparticles attributed with outstanding opto-electrical and surface properties, could serve as promising materials for photovoltaic applications especially in solar cells.

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Kolwas, Krystyna. « Optimization of Coherent Dynamics of Localized Surface Plasmons in Gold and Silver Nanospheres ; Large Size Effects ». Materials 16, n^o 5 (22 février 2023) : 1801. http://dx.doi.org/10.3390/ma16051801.

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Noble metal nanoparticles have attracted attention in recent years due to a number of their exciting applications in plasmonic applications, e.g., in sensing, high-gain antennas, structural colour printing, solar energy management, nanoscale lasing, and biomedicines. The report embraces the electromagnetic description of inherent properties of spherical nanoparticles, which enable resonant excitation of Localized Surface Plasmons (defined as collective excitations of free electrons), and the complementary model in which plasmonic nanoparticles are treated as quantum quasi-particles with discrete electronic energy levels. A quantum picture including plasmon damping processes due to the irreversible coupling to the environment enables us to distinguish between the dephasing of coherent electron motion and the decay of populations of electronic states. Using the link between classical EM and the quantum picture, the explicit dependence of the population and coherence damping rates as a function of NP size is given. Contrary to the usual expectations, such dependence for Au and Ag NPs is not a monotonically growing function, which provides a new perspective for tailoring plasmonic properties in larger-sized nanoparticles, which are still hardly available experimentally. The practical tools for comparing the plasmonic performance of gold and silver nanoparticles of the same radii in an extensive range of sizes are also given.

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Zakia, Maulida, et Seong Il Yoo. « Core–satellite assemblies of Au@polydopamine@Ag nanoparticles for photothermal-mediated catalytic reaction ». Soft Matter 16, n^o 45 (2020) : 10252–59. http://dx.doi.org/10.1039/d0sm01656j.

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dos Santos, Paulo S. S., João Mendes, B. Dias, I. Pastoriza-Santos, J. M. M. M. de Almeida et Luís C. C. Coelho. « Strongly coupled plasmonic systems on optical fiber sensors : A study on nanomaterial properties ». Journal of Physics : Conference Series 2407, n^o 1 (1 décembre 2022) : 012052. http://dx.doi.org/10.1088/1742-6596/2407/1/012052.

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Abstract New paths to increase the sensing performance of plasmonic sensors have been reported in recent years. There are several methodologies to achieve such purpose, namely by optimizing the nanostructure, nanomaterial and even the sensing platform. Recently the use nanoparticles over plasmonic thin films have been reported and shown sensitivity enhancement, when compared to a bare thin film. Nevertheless, a nanomaterial combination between NP and thin film has not been studied. In this work it was studied such plasmonic materials in order to optimize not only refractometric sensitivity but also decrease the resultant plasmonic band width. It was found that for Au, Ag and Cu thin films, the deposition of plasmonic nanoparticles resulted in an overall refractometric sensitivity and figure of merit (FOM) increase. The larger FOM increase was obtained for the Ag thin film, from 42 to 162 when coupled to Si nanoparticles. The greater sensitivity increase was achieved for a Cu thin film coupled to a Si nanoparticle, with an increase from 1745 to 3230 nm/RIU.

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Saad, A. M., M. B. Mohamed et I. M. Azzouz. « Synthesis, optical properties, and amplified spontaneous emission of hybrid Ag–SiO2–CdTe nanocomposite ». Canadian Journal of Physics 95, n^o 10 (octobre 2017) : 933–40. http://dx.doi.org/10.1139/cjp-2016-0368.

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In this work, a hybrid nanocomposite of metal–dielectric–semiconductor, Ag–SiO2–CdTe, nanoparticles has been synthesized. Silica shell was used as a spacer to isolate and control the distance between Ag plasmonic and luminescent CdTe QDs. It was found that insertion of silica shell enhances the plasmonic field more than 31%. Accordingly, Ag-SiO2 plasmonic enhances the luminescence and quantum yield of CdTe quantum dots by 200% and 55%, respectively. The threshold power of amplified spontaneous emission of CdTe was found to depend on both temperature and excitation wavelength location with respect to plasmon and exciton absorption. This nanocomposite could be potentially used in light-emitting diodes, biological sensing, and thermal therapy.

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Osváth, Zoltán, András Pálinkás, Gábor Piszter et György Molnár. « Synthesis and Characterization of Graphene–Silver Nanoparticle Hybrid Materials ». Materials 13, n^o 20 (19 octobre 2020) : 4660. http://dx.doi.org/10.3390/ma13204660.

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Silver nanoparticles (Ag NPs) play important roles in the development of plasmonic applications. Combining these nanoparticles with graphene can yield hybrid materials with enhanced light–matter interaction. Here, we report a simple method for the synthesis of graphene–silver nanoparticle hybrids on highly oriented pyrolytic graphite (HOPG) substrates. We demonstrate by scanning tunneling microscopy and local tunneling spectroscopy measurements the electrostatic n-type doping of graphene by contact with silver. We show by UV-Vis reflectance investigations that the local surface plasmon resonance (LSPR) of Ag NPs partially covered with graphene is preserved for at least three months, i.e., three times longer than the LSPR of bare Ag NPs. The gradual loss of LSPR is due to the spontaneous sulfurization of non-covered Ag NPs, as revealed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. We show that the Ag NPs completely sandwiched between graphene and HOPG do not sulfurize, even after one year.

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Linh, Vo, Xiaofei Xiao, Ho Jung, Vincenzo Giannini, Stefan Maier, Dong-Ho Kim, Yong-Ill Lee et Sung-Gyu Park. « Compact Integration of TiO2 Nanoparticles into the Cross-Points of 3D Vertically Stacked Ag Nanowires for Plasmon-Enhanced Photocatalysis ». Nanomaterials 9, n^o 3 (20 mars 2019) : 468. http://dx.doi.org/10.3390/nano9030468.

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The compact integration of semiconductor TiO2 nanoparticles (NPs) into the 3D crossed region of stacked plasmonic Ag nanowires (NWs) enhanced the photocatalytic activities through synergistic effects between the strong localized surface plasmon resonance (LSPR) excitation at the 3D cross-points of the Ag NWs and the efficient hot electron transfer at the interface between the Ag NWs and the TiO2 NPs. This paper explored new hybrid nanostructures based on the selective assembly of TiO2 NPs onto 3D cross-points of vertically stacked Ag NWs. The assembled TiO2 NPs directly contacted the 3D Ag NWs; therefore, charge separation occurred efficiently at the interface between the Ag NWs and the TiO2 NPs. The composite nanomaterials exhibited high extinction across the ultraviolet-visible range, rendering the nanomaterials high-performance photocatalysts across the full (ultraviolet-visible) and the visible spectral regions. Theoretical simulations clearly revealed that the local plasmonic field was highly enhanced at the 3D crossed regions of the vertically stacked Ag NWs. A Raman spectroscopic analysis of probe dye molecules under photodegradation conditions clearly revealed that the nanogap in the 3D crossed region was crucial for facilitating plasmon-enhanced photocatalysis and plasmon-enhanced spectroscopy.

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Kane, Kenneth A., et Massimo F. Bertino. « Pulsed laser synthesis of highly active Ag–Rh and Ag–Pt antenna–reactor-type plasmonic catalysts ». Beilstein Journal of Nanotechnology 10 (26 septembre 2019) : 1958–63. http://dx.doi.org/10.3762/bjnano.10.192.

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Ag, Pt, and Rh monometallic colloids were produced via laser ablation. Separate Ag–Rh and Ag–Pt heterostructures were formed by mixing and resulted in groupings of Rh/Pt nanoparticles adsorbing to the concavities of the larger Ag nanostructures. The 400 nm Ag plasmonic absorption peak was slightly blue-shifted for Ag–Pt and red-shifted for Ag–Rh heterostructures. Catalytic activity for the reduction of 4-nitrophenol increased significantly for Ag–Pt and Ag–Rh compared to the monometallic constituents, and persisted at lower loading ratios and consecutive reduction cycles. The enhancement is attributed to the Rh and Pt nanoparticles forming antenna–reactor-type plasmonic catalysts with the Ag nanostructures.

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Mamonova, Daria V., Anna A. Vasileva, Yuri V. Petrov, Denis V. Danilov, Ilya E. Kolesnikov, Alexey A. Kalinichev, Julien Bachmann et Alina A. Manshina. « Laser-Induced Deposition of Plasmonic Ag and Pt Nanoparticles, and Periodic Arrays ». Materials 14, n^o 1 (22 décembre 2020) : 10. http://dx.doi.org/10.3390/ma14010010.

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Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating

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Beshr, M., E. Dexter, P. E. Tierney, A. D. Meade, S. Murphy et G. Amarandei. « Towards plasmon mapping of SERS-active Ag dewetted nanostructures using SPELS ». Journal of Physics : Conference Series 2172, n^o 1 (1 février 2022) : 012012. http://dx.doi.org/10.1088/1742-6596/2172/1/012012.

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Abstract Thermal dewetting of silver thin flm can lead to SERS-active Ag nanoparticles. Here, we report our progress towards using scanning probe energy loss spectroscopy (SPELS) to map the plasmonic behaviour of SERS-active Ag nanoparticles (NP) by investigating NPs produced through the dewetting study of Ag thin flms on SiO2/Si and Ti/SiO2/Si substrates. The nanoparticles size and spatial distribution were controlled by the deposition and thermal annealing parameters. The results of preliminary SPELS measurements of these structures, alongside SERS data show that there is a correlation between the Raman enhancement and the nanoparticle size and interparticle spacing.

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Naya, Shin-ichi, Musashi Fujishima et Hiroaki Tada. « Synthesis of Au–Ag Alloy Nanoparticle-Incorporated AgBr Crystals ». Catalysts 9, n^o 9 (3 septembre 2019) : 745. http://dx.doi.org/10.3390/catal9090745.

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Nanoscale composites consisting of silver and silver halide (Ag–AgX, X = Cl, Br, I) have attracted much attention as a novel type of visible-light photocatalyst (the so-called plasmonic photocatalysts), for solar-to-chemical transformations. Support-free Au–Ag alloy nanoparticle-incorporated AgBr crystals (Au–Ag@AgBr) were synthesized by a photochemical method. At the initial step, Au ion-doped AgBr particles were prepared by adding an aqueous solution of AgNO3 to a mixed aqueous solution of KBr and HAuBr4. At the next step, UV-light illumination (λ = 365 nm) of a methanol suspension of the resulting solids yielded Au–Ag alloy nanoparticles with a mean size of approximately 5 nm in the micrometer-sized AgBr crystals. The mole percent of Au to all the Ag in Au–Ag@AgBr was controlled below < 0.16 mol% by the HAuBr4 concentration in the first step. Finite-difference time-domain calculations indicated that the local electric field enhancement factor for the alloy nanoparticle drastically decreases with an increase in the Au content. Also, the peak of the localized surface plasmon resonance shifts towards longer wavelengths with increasing Au content. Au–Ag@AgBr is a highly promising plasmonic photocatalyst for sunlight-driven chemical transformations due to the compatibility of the high local electric field enhancement and sunlight harvesting efficiency.

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Mattox, Tracy, et Jeffrey Urban. « Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat : A Review ». Materials 11, n^o 12 (5 décembre 2018) : 2473. http://dx.doi.org/10.3390/ma11122473.

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While traditional noble metal (Ag, Au, and Cu) nanoparticles are well known for their plasmonic properties, they typically only absorb in the ultraviolet and visible regions. The study of metal hexaborides, lanthanum hexaboride (LaB6) in particular, expands the available absorbance range of these metals well into the near-infrared. As a result, LaB6 has become a material of interest for its energy and heat absorption properties, most notably to those trying to absorb solar heat. Given the growing popularity of LaB6, this review focuses on the advances made in the past decade with respect to controlling the plasmonic properties of LaB6 nanoparticles. This review discusses the fundamental structure of LaB6 and explains how decreasing the nanoparticle size changes the atomic vibrations on the surface and thus the plasmonic absorbance band. We explain how doping LaB6 nanoparticles with lanthanide metals (Y, Sm, and Eu) red-shifts the absorbance band and describe research focusing on the correlation between size dependent and morphological effects on the surface plasmon resonance. This work also describes successes that have been made in dispersing LaB6 nanoparticles for various optical applications, highlighting the most difficult challenges encountered in this field of study.

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Fernández-Martínez, Javier, Sol Carretero-Palacios, Pablo Molina, Jorge Bravo-Abad, Mariola O. Ramírez et Luisa E. Bausá. « Silver Nanoparticle Chains for Ultra-Long-Range Plasmonic Waveguides for Nd3+ Fluorescence ». Nanomaterials 12, n^o 23 (3 décembre 2022) : 4296. http://dx.doi.org/10.3390/nano12234296.

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Plasmonic waveguides have been shown to be a promising approach to confine and transport electromagnetic energy beyond the diffraction limit. However, ohmic losses generally prevent their integration at micrometric or millimetric scales. Here, we present a gain-compensated plasmonic waveguide based on the integration of linear chains of Ag nanoparticles on an optically active Nd3+-doped solid-state gain medium. By means of dual confocal fluorescence microscopy, we demonstrate long-range optical energy propagation due to the near-field coupling between the plasmonic nanostructures and the Nd3+ ions. The subwavelength fluorescence guiding is monitored at distances of around 100 µm from the excitation source for two different emission ranges centered at around 900 nm and 1080 nm. In both cases, the guided fluorescence exhibits a strong polarization dependence, consistent with the polarization behavior of the plasmon resonance supported by the chain. The experimental results are interpreted through numerical simulations in quasi-infinite long chains, which corroborate the propagation features of the Ag nanoparticle chains at both excitation (λexc = 590 nm) and emission wavelengths. The obtained results exceed by an order of magnitude that of previous reports on electromagnetic energy transport using linear plasmonic chains. The work points out the potential of combining Ag nanoparticle chains with a small interparticle distance (~2 nm) with rare-earth-based optical gain media as ultra-long-range waveguides with extreme light confinement. The results offer new perspectives for the design of integrated hybrid plasmonic–photonic circuits based on rare-earth-activated solid-state platforms.

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Kornilova, Anastasiia V., Sergey M. Novikov, Galiya A. Kuralbayeva, Subhra Jana, Ivan V. Lysenko, Anastasia I. Shpichka, Anna V. Stavitskaya et al. « Halloysite Nanotubes with Immobilized Plasmonic Nanoparticles for Biophotonic Applications ». Applied Sciences 11, n^o 10 (17 mai 2021) : 4565. http://dx.doi.org/10.3390/app11104565.

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Halloysite nanotubes (HNTs) with immobilized gold (Au) and silver (Ag) nanoparticles (NPs) belong to a class of nanocomposite materials whose physical properties and applications depend on the geometry of arrangements of the plasmonic nanoparticles on HNT’ surfaces. We explore HNTs:(Au, Ag)-NPs as potential nano-templates for surface-enhanced Raman scattering (SERS). The structure and plasmonic properties of nanocomposites based on HNTs and Au- and Ag-NPs are studied by means of the transmission electron microscopy and optical spectroscopy. The optical extinction spectra of aqueous suspensions of HNTs:(Au, Ag)-NPs and spatial distributions of the electric fields are simulated, and the simulation results demonstrate the corresponding localized plasmonic resonances and numerous “hot spots” of the electric field nearby those NPs. In vitro experiments reveal an enhancement of the protein SERS in fibroblast cells with added HNTs:Ag-NPs. The observed optical properties and SERS activity of the nanocomposites based on HNTs and plasmonic NPs are promising for their applications in biosensorics and biophotonics.

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Pan, Hanqing, et Michael D. Heagy. « Plasmon-enhanced photocatalysis : Ag/TiO2 nanocomposite for the photochemical reduction of bicarbonate to formic acid ». MRS Advances 4, n^o 07 (2019) : 425–33. http://dx.doi.org/10.1557/adv.2018.677.

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ABSTRACTPlasmonic metallic nanoparticles can significantly enhance the catalytic efficiency of semiconductors via plasmonic photocatalysis. In this study, a hybrid Ag/TiO2 photocatalyst was synthesized and tested for the photochemical reduction of bicarbonate to value-added formic acid. It was found that under solar irradiation, TiO2 is not very efficient, but formate production is significantly increased with the addition of silver nanoparticles. Under 365 nm irradiation, the photocatalytic efficiency of TiO2 is enhanced, but no effect was observed with the addition of silver nanoparticles. Under solar irradiation, Ag/TiO2 reached an apparent quantum efficiency (AQE) of 7.78 ± 0.04%, the highest AQE observed so far. Enhanced photocatalytic activity is attributed to the synergistic effect between UV photon excitation of TiO2 and surface plasmon resonance enhancement. To elucidate the mechanism of plasmon-enhanced photocatalysis, experiments were performed under solar irradiation and 365 nm irradiation. We propose that photo-excited electrons are transferred from above the Fermi level of the metal nanoparticle to the conduction band of the semiconductor through plasmon-induced electron transfer.

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Li, Xianglin, Zhiwei Wang, Chiew Tan, Zexiang Shen et Alfred Tok. « Ordered Array of Metal Particles on Semishell Separated with Ultrathin Oxide : Fabrication and SERS Properties ». Coatings 9, n^o 1 (29 décembre 2018) : 20. http://dx.doi.org/10.3390/coatings9010020.

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Metal particles in gap cavities provide an interesting system to achieve hybrid local surface plasmon modes for local field enhancement. Here, we demonstrate a relatively simple method to fabricate Ag nanoparticles positioned on Ag semishells separated by a thin (~5 nm) dielectric layer. The obtained structure can provide strong local electric field enhancement for surface-enhanced Raman scattering (SERS). The fabrication of the ordered array structure was realized by nanosphere self-assembly, atomic layer deposition, and metal thin-film dewetting. Numerical simulation proved that, compared to the conventional metal semishell arrays, the additional Ag particles introduce extra hot spots particularly in the valley regions between adjacent Ag semishells. As a result, the SERS enhancement factor of the metal semishell-based plasmonic structure could be further improved by an order of magnitude. The developed novel plasmonic structure also shows good potential for application in plasmon-enhanced solar water-splitting devices.

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Hahm, Eunil, Ahla Jo, Sang Hun Lee, Homan Kang, Xuan-Hung Pham et Bong-Hyun Jun. « Silica Shell Thickness-Dependent Fluorescence Properties of SiO2@Ag@SiO2@QDs Nanocomposites ». International Journal of Molecular Sciences 23, n^o 17 (2 septembre 2022) : 10041. http://dx.doi.org/10.3390/ijms231710041.

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Silica shell coatings, which constitute important technology for nanoparticle (NP) developments, are utilized in many applications. The silica shell’s thickness greatly affects distance-dependent optical properties, such as metal-enhanced fluorescence (MEF) and fluorescence quenching in plasmonic nanocomposites. However, the precise control of silica-shell thicknesses has been mainly conducted on single metal NPs, and rarely on complex nanocomposites. In this study, silica shell-coated Ag nanoparticle-assembled silica nanoparticles (SiO2@Ag@SiO2), with finely controlled silica shell thicknesses (4 nm to 38 nm), were prepared, and quantum dots (QDs) were introduced onto SiO2@Ag@SiO2. The dominant effect between plasmonic quenching and MEF was defined depending on the thickness of the silica shell between Ag and QDs. When the distance between Ag NPs to QDs was less than ~10 nm, SiO2@Ag@SiO2@QDs showed weaker fluorescence intensities than SiO2@QD (without metal) due to the quenching effect. On the other hand, when the distance between Ag NPs to QDs was from 10 nm to 14 nm, the fluorescence intensity of SiO2@Ag@SiO2@QD was stronger than SiO2@QDs due to MEF. The results provide background knowledge for controlling the thickness of silica shells in metal-containing nanocomposites and facilitate the development of potential applications utilizing the optimal plasmonic phenomenon.

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Katsiaounis, Stavros, Julianna Panidi, Ioannis Koutselas et Emmanuel Topoglidis. « Fully Reversible Electrically Induced Photochromic-Like Behaviour of Ag:TiO2 Thin Films ». Coatings 10, n^o 2 (3 février 2020) : 130. http://dx.doi.org/10.3390/coatings10020130.

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A TiO2 thin film, prepared on fluorine-doped indium tin oxide (FTO)-coated glass substrate, from commercial off-the-shelf terpinol-based paste, was used to directly adsorb Ag plasmonic nanoparticles capped with polyvinylpyrollidone (PVP) coating. The TiO2 film was sintered before the surface entrapment of Ag nanoparticles. The composite was evaluated in terms of spectroelectrochemical measurements, cyclic voltammetry as well as structural methods such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found that the Ag nanoparticles are effectively adsorbed on the TiO2 film, while application of controlled voltages leads to a fully reversible shift of the plasmon peak from 413 nm at oxidation inducing voltages to 440 nm at reducing voltages. This phenomenon allows for the fabrication of a simple photonic switch at either or both wavelengths. The phenomenon of the plasmon shift is due to a combination of plasmon shift related to the form and dielectric environment of the nanoparticles.

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Rahman, Atta Ur, Junping Geng, Richard W. Ziolkowski, Tao Hang, Qaisar Hayat, Xianling Liang, Sami Ur Rehman et Ronghong Jin. « Photoluminescence Revealed Higher Order Plasmonic Resonance Modes and Their Unexpected Frequency Blue Shifts in Silver-Coated Silica Nanoparticle Antennas ». Applied Sciences 9, n^o 15 (26 juillet 2019) : 3000. http://dx.doi.org/10.3390/app9153000.

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Higher order plasmonic resonance modes and their frequency blue shifts in silver-coated silica nanoparticle antennas are studied. Synthesizing them with a wet chemistry method, silica (SiO2) nanoparticles were enclosed within silver shells with different thicknesses. A size-dependent Drude model was used to model the plasmonic shells and their optical losses. Two higher order plasmonic resonances were identified for each case in these simulations. The photoluminescence spectroscopy (PL) experimental results, in good agreement with their simulated values, confirmed the presence of those two higher order resonant modes and their resonance frequencies. When compared with pure metallic Ag nanoparticles, size-induced blue shifts were observed in these resonance frequencies.

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Singh, Y. Premkumar, Amit Jain et Avinashi Kapoor. « Localized Surface Plasmons Enhanced Light Transmission into c-Silicon Solar Cells ». Journal of Solar Energy 2013 (24 juillet 2013) : 1–6. http://dx.doi.org/10.1155/2013/584283.

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The paper investigates the light incoupling into c-Si solar cells due to the excitation of localized surface plasmon resonances in periodic metallic nanoparticles by finite-difference time-domain (FDTD) technique. A significant enhancement of AM1.5G solar radiation transmission has been demonstrated by depositing nanoparticles of various metals on the upper surface of a semi-infinite Si substrate. Plasmonic nanostructures located close to the cell surface can scatter incident light efficiently into the cell. Al nanoparticles were found to be superior to Ag, Cu, and Au nanoparticles due to the improved transmission of light over almost the entire solar spectrum and, thus, can be a potential low-cost plasmonic metal for large-scale implementation of solar cells.

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Barbillon, Grégory. « Latest Novelties on Plasmonic and Non-Plasmonic Nanomaterials for SERS Sensing ». Nanomaterials 10, n^o 6 (19 juin 2020) : 1200. http://dx.doi.org/10.3390/nano10061200.

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An explosion in the production of substrates for surface enhanced Raman scattering (SERS) has occurred using novel designs of plasmonic nanostructures (e.g., nanoparticle self-assembly), new plasmonic materials such as bimetallic nanomaterials (e.g., Au/Ag) and hybrid nanomaterials (e.g., metal/semiconductor), and new non-plasmonic nanomaterials. The novel plasmonic nanomaterials can enable a better charge transfer or a better confinement of the electric field inducing a SERS enhancement by adjusting, for instance, the size, shape, spatial organization, nanoparticle self-assembly, and nature of nanomaterials. The new non-plasmonic nanomaterials can favor a better charge transfer caused by atom defects, thus inducing a SERS enhancement. In last two years (2019–2020), great insights in the fields of design of plasmonic nanosystems based on the nanoparticle self-assembly and new plasmonic and non-plasmonic nanomaterials were realized. This mini-review is focused on the nanoparticle self-assembly, bimetallic nanoparticles, nanomaterials based on metal-zinc oxide, and other nanomaterials based on metal oxides and metal oxide-metal for SERS sensing.

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Gómez-Tornero, Alejandro, Luisa E. Bausá et Mariola O. Ramírez. « Giant Second Harmonic Generation Enhancement by Ag Nanoparticles Compactly Distributed on Hexagonal Arrangements ». Nanomaterials 11, n^o 9 (14 septembre 2021) : 2394. http://dx.doi.org/10.3390/nano11092394.

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The association of plasmonic nanostructures with nonlinear dielectric systems has been shown to provide useful platforms for boosting frequency conversion processes at metal-dielectric interfaces. Here, we report on an efficient route for engineering light–matter interaction processes in hybrid plasmonic-χ(2) dielectric systems to enhance second harmonic generation (SHG) processes confined in small spatial regions. By means of ferroelectric lithography, we have fabricated scalable micrometric arrangements of interacting silver nanoparticles compactly distributed on hexagonal regions. The fabricated polygonal microstructures support both localized and extended plasmonic modes, providing large spatial regions of field enhancement at the optical frequencies involved in the SHG process. We experimentally demonstrate that the resonant excitation of the plasmonic modes supported by the Ag nanoparticle-filled hexagons in the near infrared region produces an extraordinary 104-fold enhancement of the blue second harmonic intensity generated in the surface of a LiNbO3 crystal. The results open new perspectives for the design of efficient hybrid plasmonic frequency converters in miniaturized devices.

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Ma, Ying, Liyiming Tao, Shi Bai et Anming Hu. « Green Synthesis of Ag Nanoparticles for Plasmon-Assisted Photocatalytic Degradation of Methylene Blue ». Catalysts 11, n^o 12 (10 décembre 2021) : 1499. http://dx.doi.org/10.3390/catal11121499.

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Green synthesis of metal nanoparticles has been gaining great interest due to the increasing need for eco-friendly manufacturing and application of nanomaterials. Metal nanoparticles, especially silver nanoparticles, are widely used in water treatments and as environmental remedy. Here we present a method to synthesize silver nanoparticles at room temperature using green tea extract under visible light irradiation, along with an application for enhanced photocatalytic degradation on methylene blue (MB) dye. Ag nanoparticles were synthesized under different photoreduction times and then further characterized. The photocatalytic rate of synthesized nanoparticles was also investigated and compared with TiO2 nanowires under UV and visible light irradiations. The results showed that Ag nanoparticles can directly degrade MB dye through plasmonic excitation and electron transferring under visible light, and Ag nanoparticles can further enhance TiO2 photonic degradation by enhanced e-h separation with UV and/or a wide band light, including UV light. Ag nanoparticles under visible light photoreduction for 0.5 h presented better behavior for two kinds of plasmonic enhanced photodegradation; the average size of the nanoparticles is about 30 nm. Therefore, the green synthesized Ag nanoparticles exhibit promising prospects in chemical and biological pollutant treatment.

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Joshi, Hira, Siddharth Choudhary et S. Annapoorni. « Composite Nanostructures for Enhanced Plasmonics ». Materials Science Forum 950 (avril 2019) : 165–69. http://dx.doi.org/10.4028/www.scientific.net/msf.950.165.

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Enhancement in plasmonic response of metal nanoparticles in the form of metal/metal oxide nanocomposites is very interesting from both the theoretical understanding and application. Metal based oxide/Ag nanocomposites were synthesized by polyol process. Metal oxide nanoparticles present in nanocomposites as core and noble metal as a shell are of interest in investigation of plasmonic behavior of noble metals and sensing application. Cobalt ferrite (CoFe2O4) and ZnO were used as oxide core in the form of spherical and rod nanostructures respectively. Presence of Ag was confirmed by XRD and SEM analysis. In this paper we summarize the synthesis and characterization of plasmonic properties of composite nanostructures. Optical absorption studies performed on CoFe2O4@Ag and ZnO@Ag exhibit sharp plasmonic resonance but shifted towards lower wavelength (blue shift). An attempt has been made to explain this shift using the Mie scattering calculations based on size variation and change in the dielectric of the surrounding medium.

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Ali, Imran, Jun Chen, Saeed Ahmed Khan, Yasir Jamil, Aqeel Ahmed Shah, Abdul Karim Shah, Sadaf Jamal Gilani et al. « Photothermal Hyperthermia Study of Ag/Ni and Ag/Fe Plasmonic Particles Synthesized Using Dual-Pulsed Laser ». Magnetochemistry 9, n^o 3 (22 février 2023) : 59. http://dx.doi.org/10.3390/magnetochemistry9030059.

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Magneto-plasmonic Ag/Ni and Ag/Fe nanoparticles (NPs) were synthesized in this work using the environmentally safe and contaminant-free dual-pulsed Q-switched Nd:YAG 1064 nm laser ablation method. The optical and magnetic characteristics of synthesized nanomaterials were investigated using a vibrating sample magnetometer and an ultraviolet-visible absorption spectrometer. According to transmission electron microscopy (TEM), the shape of Ag/Ni and Ag/Fe NPs seems to be spherical, with mean diameters of 7.3 nm and 11.5 nm, respectively. X-ray diffraction (XRD) was used in order to investigate and describe the phase structures of the synthesized nanomaterials. The synthesized NPs reached maximum temperatures such as 48.9, 60, 63.4, 70, 75, and 79 °C for Ag/Ni nanofluid and 52, 56, 60, 68, 71, and 72 °C for Ag/Fe nanofluid when these nanofluids were subjected to an NIR 808 nm laser with operating powers of 1.24, 1.76, 2.36, 2.91, 3.5, and 4 W, respectively. Because of the plasmonic hyperthermia properties of nanoparticles, nanofluids display higher temperature profiles than pure water. According to these findings, plasmonic nanoparticles based on silver might be used to treat hyperthermia.

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Puišo, Judita, Valentinas Baltrušaitis, Algirdas Lazauskas, Asta Guobienė, Igoris Prosyčevas et Pranas Narmontas. « Synthesis and Characterization of Silver-Poly(Methylmethacrylate) Nanocomposite ». Key Engineering Materials 543 (mars 2013) : 80–83. http://dx.doi.org/10.4028/www.scientific.net/kem.543.80.

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Silver nanoparticles and polymethylmethacrylate (PMMA) nanocomposite was preparedin situby photo-induced thermal reduction method. The interfacial interaction of Ag nanoparticles and PMMA polymer is investigated using Fourier transform infrared spectroscopy (FTIR). Optical properties of Ag/PMMA films were characterized by UV-Vis and FTIR absorption spectroscopy. Effects of the UV and heat-treatment time on the formation of silver nanoparticles in PMMA matric matrix were studied in detail. These investigations proposed new nanocomposite structures. They can be defined as plasmonic materials with improved optical properties. Ag/PMMA structures may found a number of technological applications: in optical devices, various plasmonic sensors or even in nanomedicine.

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Nagpal, Keshav, Erwan Rauwel, Frédérique Ducroquet et Protima Rauwel. « Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles : a review ». Beilstein Journal of Nanotechnology 12 (24 septembre 2021) : 1078–92. http://dx.doi.org/10.3762/bjnano.12.80.

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Light-emitting diodes (LED) are widely employed in display applications and lighting systems. Further research on LED that incorporates carbon nanostructures and metal nanoparticles exhibiting surface plasmon resonance has demonstrated a significant improvement in device performance. These devices offer lower turn-on voltages, higher external quantum efficiencies, and luminance. De facto, plasmonic nanoparticles, such as Au and Ag have boosted the luminance of red, green, and blue emissions. When combined with carbon nanostructures they additionally offer new possibilities towards lightweight and flexible devices with better thermal management. This review surveys the diverse possibilities to combine various inorganic, organic, and carbon nanostructures along with plasmonic nanoparticles. Such combinations would allow an enhancement in the overall properties of LED.

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Huang, Tian-Hao, Cheng-Zi Jiang, Tian-Ning Xu et Zhen-Yu Tian. « Promising Photoluminescence Enhancement of Tris(8-hydroxyquinoline)aluminum by Simultaneous Localized and Propagating Surface Plasmons of Ag Nanostructures ». Applied Sciences 13, n^o 6 (16 mars 2023) : 3786. http://dx.doi.org/10.3390/app13063786.

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The continuous performance optimization of tris(8-hydroxyquinoline)aluminum (Alq3) materials is of great significance during the commercialization process of organic light-emitting diodes (OLEDs). In incorporating Ag nanostructures into Alq3, the photophysical properties are greatly improved by the plasmon–exciton coupling effect. Localized surface plasmons (LSPs) in Ag nanoparticles (NPs) efficiently increased the absorption ability. The coexistence of LSPs and propagating surface plasmons (PSPs) in Ag nanowires (NWs) leads to a PL enhancement of 5.3-fold and a full-width at half maximum (FWHM) narrowed by 10 nm. Temperature-dependent PL measurements exhibit that the plasmonic density of states (DOS) increases with decreasing temperature below 40 °C, and the thermal exchange can be accelerated by the introduction of Ag nanostructures. Effective suppression of the thermal accumulation effect is further proved by excitation intensity (EI)-dependent PL measurements. We also found that Ag nanostructures could mainly change the y coordinates in International Commission on Illumination (CIE), leading to a higher brightness. The 5372 K color temperature of an Ag NWs-embedded composite is suitable for daylight-type fluorescent OLEDs. The results would pave an effective way for further optimizing the optical performance of light-emitting materials in OLEDs.

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Hajjiah, Ali, Ishac Kandas et Nader Shehata. « Efficiency Enhancement of Perovskite Solar Cells with Plasmonic Nanoparticles : A Simulation Study ». Materials 11, n^o 9 (5 septembre 2018) : 1626. http://dx.doi.org/10.3390/ma11091626.

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Recently, hybrid organic-inorganic perovskites have been extensively studied due to their promising optical properties with relatively low-cost and simple processing. However, the perovskite solar cells have some low optical absorption in the visible spectrum, especially around the red region. In this paper, an improvement of perovskite solar cell efficiency is studied via simulations through adding plasmonic nanoparticles (NPs) at the rear side of the solar cell. The plasmonic resonance wavelength is selected to be very close to the spectrum range of lower absorption of the perovskite: around 600 nm. Both gold and silver nanoparticles (Au and Ag NPs) are selected to introduce the plasmonic effect with diameters above 40 nm, to get an overlap between the plasmonic resonance spectrum and the requested lower absorption spectrum of the perovskite layer. Simulations show the increase in the short circuit current density (Jsc) as a result of adding Au and Ag NPs, respectively. Enhancement in Jsc is observed as the diameter of both Au and Ag NPs is increased beyond 40 nm. Furthermore, there is a slight increase in the reflection loss as the thickness of the plasmonic nanoparticles at the rear side of the solar cell is increased. A significant decrease in the current loss due to transmission is achieved as the size of the nanoparticles increases. As a comparison, slightly higher enhancement in external quantum efficiency (EQE) can be achieved in case of adding Ag NPs rather than Au NPs.

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Berginc, Marko, Urša Opara Krašovec et Marko Topič. « Solution Processed Silver Nanoparticles in Dye-Sensitized Solar Cells ». Journal of Nanomaterials 2014 (2014) : 1–11. http://dx.doi.org/10.1155/2014/357979.

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A plasmonic effect of silver nanoparticles (Ag NPs) in dye-sensitized solar cells (DSSCs) is studied. The solutions of silver nitrate in isopropanol, ethylene glycol, or in TiO2sol were examined as possible precursors for Ag NPs formation. The solutions were dip-coated on the top of the porous TiO2layer. The results of optical measurements confirmed the formation of Ag NPs throughout the porous TiO2layer after the heat treatment of the layers above 100°C. Heat treatment at 220°C was found to be optimal regarding the formation of the Ag NPs. The porous TiO2layers with Ag NPs have been evaluated also in DSSC by measuring current-voltage characteristics and the external quantum efficiency of the cells. In addition, the amount of adsorbed dye has been determined to prove the plasmonic effect in the cells. TheI-Vcharacterization of the DSSCs revealed an increase of the short circuit current in the presence of Ag NPs although the amount of the attached dye molecules decreased. These results confirm that the performance enhancement is related to the plasmonic effect. However, neither a thin sol-gel TiO2layer nor poly(4-vinylpyridine) shells provide effective protection for the long term stability of the Ag NPs against the corrosion ofI3-/I-based electrolyte.

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Yang, Jianhui, Beibei Cao et Bin Liu. « Magnetic-plasmonic bifunctional CoO–Ag heterostructure nanoparticles ». Materials Research Express 1, n^o 1 (21 février 2014) : 015022. http://dx.doi.org/10.1088/2053-1591/1/1/015022.

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Taghavi Moghaddam, Seyed Enayatollah, et Farzin Emami. « Surface-Enhanced Raman Scattering Based on Au-DNA-Ag Plasmonic Nanoparticles ». Journal of Nanoelectronics and Optoelectronics 15, n^o 11 (1 novembre 2020) : 1307–11. http://dx.doi.org/10.1166/jno.2020.2855.

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The dependence of the Surface-Enhanced Raman Scattering (SERS) by gold and silver nanoparticles on their shape is examined using the organic dye, as a probe molecule. SERS has been explored extensively for applications in sensing and imaging, but the design and optimization of efficient substrates are still challenging. In order to understand and optimize the SERS process in nanoparticles, gold and silver Nanospheres and their composition as gold-DNA-silver nanoparticle were synthesized and characterized according to their average size, zeta potential and UV/visible absorption. In fact, in this research, an asymmetric new plasmonic nano-particle is proposed and designed as gold-DNA-silver and is compared to gold, silver, gold-DNA-gold, and silver-DNA-silver nanoparticles. With the help of this new nanoparticle, we design and recommend a Raman booster so that the effect of Raman is improved noticeably. It will be shown that using the proposed asymmetric nano-particle of gold-DNA-silver, the absorbance, and intensity of Raman booster is improved noticeably. In suspensions of equal nano-particle and dye concentration, the SERS effect increases as gold- DNA-silver, clearly indicating that control over the number of local field hotspots can optimize the SERS efficiency. Notably, it is demonstrated that the SERS intensity per nanoparticle scales with the magnitude of the SPR absorbance at the excitation wavelength (785 nm), providing a clear guide to optimization of the process experimentally.

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Zamboni, Francesco, Arūnė Makarevičiūtė et Vladimir N. Popok. « Long-Term Plasmonic Stability of Copper Nanoparticles Produced by Gas-Phase Aggregation Method Followed by UV-Ozone Treatment ». Applied Nano 3, n^o 2 (3 mai 2022) : 102–11. http://dx.doi.org/10.3390/applnano3020007.

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Coinage metal nanoparticles (NPs) are well-known for the phenomenon of localized surface plasmon resonance (LSPR), which is widely utilized for enhanced sensing and detection. LSPR stability over time is an important issue for the practical application of nanoparticle matrices. Some metals, and copper among those, are chemically reactive in ambient atmospheric conditions that leads to degradation of plasmonic functionality. This work reports on the formation of Cu NP matrices utilizing magnetron-sputtering gas-phase aggregation, size-selection and soft-landing on a substrate. This method provides monocrystalline NPs with high purity, thus, improving chemical inertness towards ambient gases, for example, oxygen. Additionally, a simple approach of UV-ozone treatment is shown to form an oxide shell protecting the metallic core against reactions with environmental species and stabilizing the plasmonic properties for a period of over 150 days. The suggested methodology is promising to improve the competitiveness of Cu nano-matrices with those of Au and Ag in plasmonic sensing and detection.

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Shipunova, Victoria O., Mariia M. Belova, Polina A. Kotelnikova, Olga N. Shilova, Aziz B. Mirkasymov, Natalia V. Danilova, Elena N. Komedchikova, Rachela Popovtzer, Sergey M. Deyev et Maxim P. Nikitin. « Photothermal Therapy with HER2-Targeted Silver Nanoparticles Leading to Cancer Remission ». Pharmaceutics 14, n^o 5 (8 mai 2022) : 1013. http://dx.doi.org/10.3390/pharmaceutics14051013.

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Nanoparticles exhibiting the localized surface plasmon resonance (LSPR) phenomenon are promising tools for diagnostics and cancer treatment. Among widely used metal nanoparticles, silver nanoparticles (Ag NPs) possess the strongest light scattering and surface plasmon strength. However, the therapeutic potential of Ag NPs has until now been underestimated. Here we show targeted photothermal therapy of solid tumors with 35 nm HER2-targeted Ag NPs, which were produced by the green synthesis using an aqueous extract of Lavandula angustifolia Mill. Light irradiation tests demonstrated effective hyperthermic properties of these NPs, namely heating by 10 °C in 10 min. To mediate targeted cancer therapy, Ag NPs were conjugated to the scaffold polypeptide, affibody ZHER2:342, which recognizes a clinically relevant oncomarker HER2. The conjugation was mediated by the PEG linker to obtain Ag-PEG-HER2 nanoparticles. Flow cytometry tests showed that Ag-PEG-HER2 particles successfully bind to HER2-overexpressing cells with a specificity comparable to that of full-size anti-HER2 IgGs. A confocal microscopy study showed efficient internalization of Ag-PEG-HER2 into cells in less than 2 h of incubation. Cytotoxicity assays demonstrated effective cell death upon exposure to Ag-PEG-HER2 and irradiation, caused by the production of reactive oxygen species. Xenograft tumor therapy with Ag-PEG-HER2 particles in vivo resulted in full primary tumor regression and the prevention of metastatic spread. Thus, for the first time, we have shown that HER2-directed plasmonic Ag nanoparticles are effective sensitizers for targeted photothermal oncotherapy.

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Lee, Seunghoon, Jong Wook Hong, Su-Un Lee, Young Wook Lee et Sang Woo Han. « The controlled synthesis of plasmonic nanoparticle clusters as efficient surface-enhanced Raman scattering platforms ». Chemical Communications 51, n^o 42 (2015) : 8793–96. http://dx.doi.org/10.1039/c4cc10377g.

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Gilea, Diana, Radu G. Ciocarlan, Elena M. Seftel, Pegie Cool et Gabriela Carja. « Engineering Heterostructures of Layered Double Hydroxides and Metal Nanoparticles for Plasmon-Enhanced Catalysis ». Catalysts 12, n^o 10 (11 octobre 2022) : 1210. http://dx.doi.org/10.3390/catal12101210.

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Artificially designed heterostructures formed by close conjunctions of plasmonic metal nanoparticles (PNPs) and non-plasmonic (2D) lamellar nanostructures are receiving extensive interest. The synergistic interactions of the nanounits induce the manifestation of localized surface plasmon resonance (LSPR) in plasmonic metals in the specific environment of the 2D-light absorbing matrix, impacting their potential in plasmon enhanced catalysis. Specifically, layered double hydroxides (LDH) with the advantages of their unique 2D-layered structure, tuned optical absorption, ease of preparation, composition diversity, and high surface area, have emerged as very promising candidates for obtaining versatile and robust catalysts. In this review, we cover the available PNPs/LDH heterostructures, from the most used noble-metals plasmonic of Au and Ag to the novel non-noble-metals plasmonic of Cu and Ni, mainly focusing on their synthesis strategies toward establishing a synergistic response in the coupled nanounits and relevant applications in plasmonic catalysis. First, the structure–properties relationship in LDH, establishing the desirable features of the 2D-layered matrix facilitating photocatalysis, is shortly described. Then, we address the recent research interests toward fabrication strategies for PNPs/support heterostructures as plasmonic catalysts. Next, we highlight the synthesis strategies for available PNPs/LDH heterostructures, how these are entangled with characteristics that enable the manifestation of the plasmon-induced charge separation effect (PICS), co-catalytic effect, or nanoantenna effect in plasmonic catalysis with applications in energy related and environmental photocatalysis. Finally, some perspectives on the challenges and future directions of PNPs/LDHs heterostructures to improve their performance as plasmonic catalysts are discussed.

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Das, Rupali, Parikshit Phadke, Naveen Khichar et Santa Chawla. « Plasmonic enhancement of dual mode fluorescence in a silver nano-antenna–ZnO:Er3+ hybrid nanostructure ». J. Mater. Chem. C 2, n^o 42 (2014) : 8880–85. http://dx.doi.org/10.1039/c4tc01479k.

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Articles de revues sur le sujet « Plasmonic Nanoparticles(Au, Ag) »

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