TEM characterization of chemically synthesized copper–gold nanoparticles

Tran, Dung Trung; Jones, I.P.; Preece, Jon A.; Johnston, Roy L.; Brom, Coenraad R. van den

doi:10.1007/s11051-011-0367-2

Cited by 17 publications

(16 citation statements)

References 36 publications

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“…In that paper, the HAADF-STEM imaging of a cubo-octahedral particle supported a mixed Cu-Au configuration. 453 Calvino and colleagues focused on the characterization of Au catalysts supported on a Ce-Tb-Zr mixed oxide. In general, HAADF-STEM operates well when metal NPs are dispersed within light support materials, such as zeolites or alumina, for which large differences between metal and support element atomic numbers contribute to a high contrast in the images.…”

Section: Microscopy Techniques For Np Characterizationmentioning

confidence: 99%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

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Nanostructures have attracted huge interest as a rapidly growing class of materials for many applications. Several techniques have been used to characterize the size, crystal structure, elemental composition and a variety of other physical properties of nanoparticles. In several cases, there are physical properties that can be evaluated by more than one technique. Different strengths and limitations of each technique complicate the choice of the most suitable method, while often a combinatorial characterization approach is needed. In addition, given that the significance of nanoparticles in basic research and applications is constantly increasing, it is necessary that researchers from separate fields overcome the challenges in the reproducible and reliable characterization of nanomaterials, after their synthesis and further process (e.g. annealing) stages. The principal objective of this review is to summarize the present knowledge on the use, advances, advantages and weaknesses of a large number of experimental techniques that are available for the characterization of nanoparticles. Different characterization techniques are classified according to the concept/group of the technique used, the information they can provide, or the materials that they are destined for. We describe the main characteristics of the techniques and their operation principles and we give various examples of their use, presenting them in a comparative mode, when possible, in relation to the property studied in each case.

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Section: Microscopy Techniques For Np Characterizationmentioning

confidence: 99%

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

2018

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“…Studying sub-nanometre AuCu clusters, where quantum effects are observed and where "every atom counts" [51,52], is required in order to rationalize their catalytic activity and to form a base for future experimental investigations. To the best of our knowledge, detailed, systematic studies of MgO-supported sub-nanometre AuCu clusters have not been reported, despite many publications on the structural and catalytic properties of larger free and MgO-supported AuCu nanoparticles [8,50,[53][54][55]. Theoretically, sub-nanometre sizes present a synergistic combination between employing high level theory (e.g.…”

Section: Introductionmentioning

confidence: 99%

Physico-Chemical Insights into Gas-Phase and Oxide-Supported Sub-Nanometre AuCu Clusters

Hussein

Gao

Hou

et al. 2019

Zeitschrift Für Physikalische Chemie

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Catalysis by AuCu nanoclusters is a promising scientific field. However, our fundamental understanding of the underlying mechanisms of mixing in AuCu clusters at the sub-nanometre scale and their physico-chemical properties in both the gas-phase and on oxide supports is limited. We have identified the global minima of gas-phase and MgO(100)-supported AuCu clusters with 3–10 atoms using the Mexican Enhanced Genetic Algorithm coupled with density functional theory. Au and Cu adatoms and supported dimers have been also simulated at the same level of theory. The most stable composition, as calculated from mixing and binding energies, is obtained when the Cu proportion is close to 50%. The structures of the most stable free AuCu clusters exhibit Cu-core/Au-shell segregation. On the MgO surface however, there is a preference for Cu atoms to lie at the cluster-substrate interface. Due to the interplay between the number of interfacial Cu atoms and surface-induced cluster rearrangement, on the MgO surface 3D structures become more stable than 2D structures. The O-site of MgO surface is found to be the most favourable adsorption site for both metals. All dimers favour vertical (V) configurations on the surface and their adsorption energies are in the order: AuCu < CuCu < AuAu < AuCu (where the underlined atom is bound to the O-site). For both adatoms and AuCu dimers, adsorption via Cu is more favourable than Au-adsorbed configurations, but, this disagrees with the ordering for the pure dimers due to a combination of electron transfer and the metal-on-top effect. Binding energy (and second difference) and HOMO-LUMO gap calculations show that even-atom (even-electron) clusters are more stable than the neighbouring odd-atom (odd- electron) clusters, which is expected for closed- and open-shell systems. Supporting AuCu clusters on the MgO(100) surface decreases the charge transfer between Au and Cu atoms calculated in free clusters. The results of this study may serve as a foundation for designing better AuCu catalysts.

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“…TEM was used for the characterization and visualization of different types of nanostructures, such as noble metal- and metal oxide-based NPs [105–107], carbon nanomaterials [108,109], quantum dots [110–112], or polymeric nanoparticles of a dendrimer type [113]. TEM is preferentially used in the study of nanoparticle uptake, cellular compartmentation, transport and accumulation in different tissues and organs.…”

Section: Imaging By Microscopic Techniquesmentioning

confidence: 99%

Modern Micro and Nanoparticle-Based Imaging Techniques

Ryvolová

Chomoucká

Drbohlavová

et al. 2012

Sensors

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The requirements for early diagnostics as well as effective treatment of insidious diseases such as cancer constantly increase the pressure on development of efficient and reliable methods for targeted drug/gene delivery as well as imaging of the treatment success/failure. One of the most recent approaches covering both the drug delivery as well as the imaging aspects is benefitting from the unique properties of nanomaterials. Therefore a new field called nanomedicine is attracting continuously growing attention. Nanoparticles, including fluorescent semiconductor nanocrystals (quantum dots) and magnetic nanoparticles, have proven their excellent properties for in vivo imaging techniques in a number of modalities such as magnetic resonance and fluorescence imaging, respectively. In this article, we review the main properties and applications of nanoparticles in various in vitro imaging techniques, including microscopy and/or laser breakdown spectroscopy and in vivo methods such as magnetic resonance imaging and/or fluorescence-based imaging. Moreover the advantages of the drug delivery performed by nanocarriers such as iron oxides, gold, biodegradable polymers, dendrimers, lipid based carriers such as liposomes or micelles are also highlighted.

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TEM characterization of chemically synthesized copper–gold nanoparticles

Cited by 17 publications

References 36 publications

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Characterization techniques for nanoparticles: comparison and complementarity upon studying nanoparticle properties

Physico-Chemical Insights into Gas-Phase and Oxide-Supported Sub-Nanometre AuCu Clusters

Modern Micro and Nanoparticle-Based Imaging Techniques

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