Transmission Electron Microscopy: A Multifunctional Tool for the Atomic-scale Characterization of Nanoalloys

Alloyeau, Damien

doi:10.1007/978-1-4471-4014-6_4

Cited by 7 publications

(6 citation statements)

References 93 publications

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“…Mixing two metals at the nanoscale is an original way to elaborate new nanomaterials with singular properties and potential applications in various fields (catalysis, magnetism, optics, sensing…). Such systems, called nanoalloys or bimetallic nanoparticles (BNPs), have been the subject of much research over the last two decades [1][2][3]. Their properties depend intimately on their size, shape, composition and on their chemical structure, ranging from solid solution with or without chemical ordering to segregated phases such as core@shell or "Janus"-type structures.…”

Section: Introductionmentioning

confidence: 99%

Structural and optical properties of silver-indium and silver-aluminium nanoalloys: stability against oxidation

Camus¹,

Ramade²,

Pellarin³

et al. 2022

Eur. Phys. J. Appl. Phys.

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Bimetallic nanoparticles (BNPs) are promising candidates for fundamental research and applications as their physico-chemical properties can in many cases be tuned continuously or enhanced with respect to the mono-metallic particles. Here we investigate the possibility of fabricating silver-indium and silver-aluminium BNPs in the range of 4-5 nm diameter and of varying stoichiometry by laser vaporization and gas condensation in the gas phase. We analyse their crystalline structure and segregation behaviour using transmission electron microscopy and probe their oxidation state in optical absorption measurements by tracking spectral changes of the localized surface plasmon resonance (LSPR). These complementary techniques show that, despite the small size and the high reactivity especially of aluminium, the BNPs form a silver-rich alloyed core surrounded by an oxide shell. Exposure to air leads to consecutive oxidation, whereas annealing the BNPs in a reducing atmosphere stabilizes the alloyed particle cores, as demonstrated by a narrow and blue-shifted LSPR. This is a first step towards the stabilization of non-oxidized bimetallic nanoparticles combining a noble and a trivalent metal.

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Section: Introductionmentioning

confidence: 99%

Structural and optical properties of silver-indium and silver-aluminium nanoalloys: stability against oxidation

Camus¹,

Ramade²,

Pellarin³

et al. 2022

Eur. Phys. J. Appl. Phys.

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“…We observed that shutting down the electron beam for a few minutes results in a complete reshaping of the NSs due to the surface diffusion of gold atoms from the tips to the concave surfaces (Figure a). This common diffusion process is also observed during sintering phenomena in which the migration of atoms is driven by the differences in chemical potential of surfaces with varying degree of curvatures . By shutting down the electron beam we effectively cut off the supply of Au monomers to the growing NSs and also change the pH of the solution.…”

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confidence: 82%

Exploring the Formation of Symmetric Gold Nanostars by Liquid-Cell Transmission Electron Microscopy

et al. 2017

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The shape-dependent properties of gold nanostars (NSs) have motivated massive research efforts in the field of colloidal chemistry to gain a better control over the morphology of these promising nanostructures. Nevertheless, this challenge requires a better understanding of the atomic-scale processes leading to the formation of stellated nanoparticles. We hereby report an unprecedented in situ study focused on the seed-mediated synthesis of symmetric gold NSs performed by radiolysis in methanol. We take advantage of the spatial and temporal resolutions of liquid-cell transmission electron microscopy to unravel the key effects of the growth speed, seed-crystal morphology, and dimethylamine functionalization on the formation mechanisms, shape, and stability of NSs enclosed by high-index facets. Surprisingly, the stellation processes transforming icosahedral nanoparticles into NSs with 20 sharp arms entails a continuous restructuring of NS facets driven by surface diffusion, which provide a fresh look at faceting mechanisms.

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“…[37][38][39][40] A large number of electrons participate in the surface plasmonic resonance, improving the proximity field at the intrinsic frequency of the plasmonic metal NPs. 41,42 Thin-film solar cells such as organic solar cells [43][44][45][46] and PSCs [47][48][49][50] have exploited the properties of metal NPs to boost their PCE. However, it should be emphasized that applications of metal NP in PSCs are much fewer than those in organic solar cells.…”

Section: Introductionmentioning

confidence: 99%

Upcycled synthesis and extraction of carbon‐encapsulated iron carbide nanoparticles for gap Plasmon applications in perovskite solar cells

Han

Kim

Tavakkoli

et al. 2023

EcoMat

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An effective method for obtaining large amounts of metal nanoparticles (NPs) encapsulated by carbon layers through upcycling from floating-catalyst aerosol chemical vapor-deposited carbon nanotubes is demonstrated. NPs with diameters of less than 20 μm are selectively extracted from the synthesized carbon assortments through sonication, centrifugation, and filtration. The particles show an aggregation behavior owing to the π-π interaction between the graphitic carbon shells surrounding the iron carbides. By controlling the degree of the aggregation and arrangement, the light scattering by the gap-surface plasmon effect in perovskite solar cells is maximized. Application of the NPs to the devices increased the power conversion efficiency from 19.71% to 21.15%. The short-circuit current density (J SC ) trend over the particle aggregation time accounts for the plasmonic effect. The devices show high stability analogue to the control devices, confirming that no metal-ion migration took place thanks to the encapsulation.

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Transmission Electron Microscopy: A Multifunctional Tool for the Atomic-scale Characterization of Nanoalloys

Cited by 7 publications

References 93 publications

Structural and optical properties of silver-indium and silver-aluminium nanoalloys: stability against oxidation

Structural and optical properties of silver-indium and silver-aluminium nanoalloys: stability against oxidation

Exploring the Formation of Symmetric Gold Nanostars by Liquid-Cell Transmission Electron Microscopy

Upcycled synthesis and extraction of carbon‐encapsulated iron carbide nanoparticles for gap Plasmon applications in perovskite solar cells

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