Records |
Author |
Wu, L.; Kolmeijer, K.E.; Zhang, Y.; An, H.; Arnouts, S.; Bals, S.; Altantzis, T.; Hofmann, J.P.; Costa Figueiredo, M.; Hensen, E.J.M.; Weckhuysen, B.M.; van der Stam, W. |
Title |
Stabilization effects in binary colloidal Cu and Ag nanoparticle electrodes under electrochemical CO₂ reduction conditions |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
13 |
Issue |
9 |
Pages |
4835-4844 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
Abstract |
Nanoparticle modified electrodes constitute an attractive way to tailor-make efficient carbon dioxide (CO2) reduction catalysts. However, the restructuring and sintering processes of nanoparticles under electrochemical reaction conditions not only impedes the widespread application of nanoparticle catalysts, but also misleads the interpretation of the selectivity of the nanocatalysts. Here, we colloidally synthesized metallic copper (Cu) and silver (Ag) nanoparticles with a narrow size distribution (<10%) and utilized them in electrochemical CO2 reduction reactions. Monometallic Cu and Ag nanoparticle electrodes showed severe nanoparticle sintering already at low overpotential of -0.8 V vs. RHE, as evidenced by ex situ SEM investigations, and potential-dependent variations in product selectivity that resemble bulk Cu (14% for ethylene at -1.3 V vs. RHE) and Ag (69% for carbon monoxide at -1.0 V vs. RHE). However, by co-deposition of Cu and Ag nanoparticles, a nanoparticle stabilization effect was observed between Cu and Ag, and the sintering process was greatly suppressed at CO2 reducing potentials (-0.8 V vs. RHE). Furthermore, by varying the Cu/Ag nanoparticle ratio, the CO2 reduction reaction (CO2RR) selectivity towards methane (maximum of 20.6% for dense Cu-2.5-Ag-1 electrodes) and C-2 products (maximum of 15.7% for dense Cu-1-Ag-1 electrodes) can be tuned, which is attributed to a synergistic effect between neighbouring Ag and Cu nanoparticles. We attribute the stabilization of the nanoparticles to the positive enthalpies of Cu-Ag solid solutions, which prevents the dissolution-redeposition induced particle growth under CO2RR conditions. The observed nanoparticle stabilization effect enables the design and fabrication of active CO2 reduction nanocatalysts with high durability. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000628024200011 |
Publication Date |
2021-02-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
24 |
Open Access |
OpenAccess |
Notes |
This work is funded by the Strategic UU-TU/e Alliance project ‘Joint Centre for Chemergy Research’ (budget holder B. M. W.). S. B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO). S. A. and T. A. acknowledge funding from the University of Antwerp Research fund (BOF). We thank Eric Hellebrand (Faculty of Geosciences, Utrecht University) for the assistance in SEM measurements. Dr Ramon Oord (ARC Chemical Building Blocks Consortium, Faculty of Science, Utrecht University) is acknowledged for assisting with the grazing incidence XRD measurements; sygma |
Approved |
Most recent IF: 7.367 |
Call Number |
UA @ admin @ c:irua:176723 |
Serial |
6737 |
Permanent link to this record |
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Author |
Payne, L.M.; Albrecht, W.; Langbein, W.; Borri, P. |
Title |
The optical nanosizer – quantitative size and shape analysis of individual nanoparticles by high-throughput widefield extinction microscopy |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Nanoparticles are widely utilised for a range of applications, from catalysis to medicine, requiring accurate knowledge of their size and shape. Current techniques for particle characterisation are either not very accurate or time consuming and expensive. Here we demonstrate a rapid and quantitative method for particle analysis based on measuring the polarisation-resolved optical extinction cross-section of hundreds of individual nanoparticles using wide-field microscopy, and determining the particle size and shape from the optical properties. We show measurements on three samples consisting of nominally spherical gold nanoparticles of 20 nm and 30 nm diameter, and gold nanorods of 30 nm length and 10 nm diameter. Nanoparticle sizes and shapes in three dimensions are deduced from the measured optical cross-sections at different wavelengths and light polarisation, by solving the inverse problem, using an ellipsoid model of the particle polarisability in the dipole limit. The sensitivity of the method depends on the experimental noise and the choice of wavelengths. We show an uncertainty down to about 1 nm in mean diameter, and 10% in aspect ratio when using two or three color channels, for a noise of about 50 nm<sup>2</sup>in the measured cross-section. The results are in good agreement with transmission electron microscopy, both 2D projection and tomography, of the same sample batches. Owing to its combination of experimental simplicity, ease of access to statistics over many particles, accuracy, and geometrical particle characterisation in 3D, this “optical nanosizer” method has the potential to become the technique of choice for quality control in next-generation particle manufacturing. |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000558928800022 |
Publication Date |
2020-07-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
This work was supported by a Welsh Government Life Sciences Bridging Fund (grant LSBF/R6-005) and by the UK EPSRC (grant no. EP/I005072/1 and EP/M028313/1). PB acknowledges the Royal Society for her Wolfson research merit award (grant WM140077). The authors acknowledge funding from the European Commission (Grant EUSMI E191000350). WA acknowledges an Individual Fellowship from the Marie Sklodowska-Curie actions (MSCA) under the EU’s Horizon 2020 program (Grant 797153, SOPMEN), and Sara Bals for supporting the STEM measurements. The bright-field TEM was performed by Thomas Davies at Cardiff University. We acknowledge Attilio Zilli for helpful discussions and contributions in calculating the relative field strengths in the illumination and finite-element simulation of cross-sections shown in the ESI.† We acknowledge Iestyn Pope for technical support of the optical equipment. |
Approved |
Most recent IF: 6.7; 2020 IF: 7.367 |
Call Number |
UA @ lucian @c:irua:170485 |
Serial |
6397 |
Permanent link to this record |
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Author |
Liu, P.; Arslan Irmak, E.; De Backer, A.; De wael, A.; Lobato, I.; Béché, A.; Van Aert, S.; Bals, S. |
Title |
Three-dimensional atomic structure of supported Au nanoparticles at high temperature |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
13 |
Issue |
|
Pages |
|
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well known that the activity of Au NPs depends on their size and surface structure, their three-dimensional (3D) structure at the atomic scale has not been completely characterized as a function of temperature. In this paper, we overcome the limitations of conventional electron tomography by combining atom counting applied to aberration-corrected scanning transmission electron microscopy images and molecular dynamics relaxation. In this manner, we are able to perform an atomic resolution 3D investigation of supported Au NPs. Our results enable us to characterize the 3D equilibrium structure of single NPs as a function of temperature. Moreover, the dynamic 3D structural evolution of the NPs at high temperatures, including surface layer jumping and crystalline transformations, has been studied. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000612999200029 |
Publication Date |
2020-12-29 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
13 |
Open Access |
OpenAccess |
Notes |
This work was supported by the European Research Council (Grant 815128 REALNANO to SB, Grant 770887 PICOMETRICS to SVA, Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A. D. w. and A. D. B. and project funding G.0267.18N.; sygma; esteem3JRA; esteem3reported |
Approved |
Most recent IF: 7.367 |
Call Number |
EMAT @ emat @c:irua:174858 |
Serial |
6665 |
Permanent link to this record |
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Author |
Zheng, G.; Chen, Z.; Sentosun, K.; Pérez-Juste, I.; Bals, S.; Liz-Marzán, L.M.; Pastoriza-Santos, I.; Pérez-Juste, J.; Hong, M. |
Title |
Shape control in ZIF-8 nanocrystals and metal nanoparticles@ZIF-8 heterostructures |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
9 |
Issue |
9 |
Pages |
16645-16651 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Shape control in metal-organic frameworks still remains a challenge. We propose a strategy based on the capping agent modulator method to control the shape of ZIF-8 nanocrystals. This approach requires the use of a surfactant, cetyltrimethylammonium bromide (CTAB), and a second capping agent, tris(hydroxymethyl)aminomethane (TRIS), to obtain ZIF-8 nanocrystals with morphology control in aqueous media. Semiempirical computational simulations suggest that both shape-inducing agents adsorb onto different surface facets of ZIF-8, thereby slowing down their crystal growth rates. While CTAB molecules preferentially adsorb onto the {100} facets, leading to ZIF-8 particles with cubic morphology, TRIS preferentially stabilizes the {111} facets, inducing the formation of octahedral crystals. Interestingly, the presence of both capping agents leads to nanocrystals with irregular shapes and higher index facets, such as hexapods and burr puzzles. Additionally, the combination of ZIF-8 nanocrystals with other materials is expected to impart additional properties due to the hybrid nature of the resulting nanocomposites. In the present case, the presence of CTAB and TRIS molecules as capping agents facilitates the synthesis of metal nanoparticle@ZIF-8 nanocomposites, due to synergistic effects which could be of use in a number of applications such as catalysis, gas sensing and storage. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000414960900015 |
Publication Date |
2017-07-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
109 |
Open Access |
OpenAccess |
Notes |
This work was supported by the Ministerio de Economía y Competitividad (MINECO, Spain), under the Grants MAT2013- 45168-R and MAT2016-77809-R. This study was also funded by the Xunta de Galicia/FEDER (ED431C 2016-048). We are grateful to the financial support from National Natural Science Foundation of China (21671010), Guangdong Science and Technology Program (2013A061401002), and Shenzhen Strategic Emerging Industries (KQCX2015032709315529, CXZZ20140419131807788). |
Approved |
Most recent IF: 7.367 |
Call Number |
EMAT @ emat @c:irua:145827UA @ admin @ c:irua:145827 |
Serial |
4705 |
Permanent link to this record |
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Author |
Khalilov, U.; Bogaerts, A.; Xu, B.; Kato, T.; Kaneko, T.; Neyts, E.C. |
Title |
How the alignment of adsorbed ortho H pairs determines the onset of selective carbon nanotube etching |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
9 |
Issue |
9 |
Pages |
1653-1661 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
Unlocking the enormous technological potential of carbon nanotubes strongly depends on our ability to specifically produce metallic or semiconducting tubes. While selective etching of both has already been demonstrated, the underlying reasons, however, remain elusive as yet. We here present computational and experimental evidence on the operative mechanisms at the atomic scale. We demonstrate that during the adsorption of H atoms and their coalescence, the adsorbed ortho hydrogen pairs on single-walled carbon nanotubes induce higher shear stresses than axial stresses, leading to the elongation of HC–CH bonds as a function of their alignment with the tube chirality vector, which we denote as the γ-angle. As a result, the C–C cleavage occurs more rapidly in nanotubes containing ortho H-pairs with a small γ-angle. This phenomenon can explain the selective etching of small-diameter semiconductor nanotubes with a similar curvature. Both theoretical and experimental results strongly indicate the important role of the γ-angle in the selective etching mechanisms of carbon nanotubes, in addition to the nanotube curvature and metallicity effects and lead us to clearly understand the onset of selective synthesis/removal of CNT-based materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000395422800036 |
Publication Date |
2016-12-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
6 |
Open Access |
OpenAccess |
Notes |
U. K. gratefully acknowledges financial support from the Fund of Scientific Research Flanders (FWO), Belgium (Grant No. 12M1315N). This work was also supported in part by Grant-in- Aid for Young Scientists A (Grant No. 25706028), Grant-in-Aid for Scientific Research on Innovative Areas (Grant No. 26107502) from JSPS KAKENHI. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UA. The authors also thank Prof. A. C. T. van Duin for sharing the ReaxFF code and J. Razzokov for his assistance to perform the DFT calculations. |
Approved |
Most recent IF: 7.367 |
Call Number |
PLASMANT @ plasmant @ c:irua:140091 |
Serial |
4417 |
Permanent link to this record |
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Author |
Borgatti, F.; Park, C.; Herpers, A.; Offi, F.; Egoavil, R.; Yamashita, Y.; Yang, A.; Kobata, M.; Kobayashi, K.; Verbeeck, J.; Panaccione, G.; Dittmann, R.; |
Title |
Chemical insight into electroforming of resistive switching manganite heterostructures |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
5 |
Issue |
9 |
Pages |
3954-3960 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
We have investigated the role of the electroforming process in the establishment of resistive switching behaviour for Pt/Ti/Pr0.5Ca0.5MnO3/SrRuO3 layered heterostructures (Pt/Ti/PCMO/SRO) acting as non-volatile Resistance Random Access Memories (RRAMs). Electron spectroscopy measurements demonstrate that the higher resistance state resulting from electroforming of as-prepared devices is strictly correlated with the oxidation of the top electrode Ti layer through field-induced electromigration of oxygen ions. Conversely, PCMO exhibits oxygen depletion and downward change of the chemical potential for both resistive states. Impedance spectroscopy analysis, supported by the detailed knowledge of these effects, provides an accurate model description of the device resistive behaviour. The main contributions to the change of resistance from the as-prepared (low resistance) to the electroformed (high resistance) states are respectively due to reduced PCMO at the boundary with the Ti electrode and to the formation of an anisotropic np junction between the Ti and the PCMO layers. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000317859400051 |
Publication Date |
2013-03-05 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364;2040-3372; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.367 |
Times cited |
40 |
Open Access |
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Notes |
Vortex; Countatoms ECASJO_; |
Approved |
Most recent IF: 7.367; 2013 IF: 6.739 |
Call Number |
UA @ lucian @ c:irua:108710UA @ admin @ c:irua:108710 |
Serial |
348 |
Permanent link to this record |
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Author |
Wang, Y.; Sztranyovszky, Z.; Zilli, A.; Albrecht, W.; Bals, S.; Borri, P.; Langbein, W. |
Title |
Quantitatively linking morphology and optical response of individual silver nanohedra |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
14 |
Issue |
30 |
Pages |
11028-11037 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The optical response of metal nanoparticles is governed by plasmonic resonances, which are dictated by the particle morphology. A thorough understanding of the link between morphology and optical response requires quantitatively measuring optical and structural properties of the same particle. Here we present such a study, correlating electron tomography and optical micro-spectroscopy. The optical measurements determine the scattering and absorption cross-section spectra in absolute units, and electron tomography determines the 3D morphology. Numerical simulations of the spectra for the individual particle geometry, and the specific optical set-up used, allow for a quantitative comparison including the cross-section magnitude. Silver nanoparticles produced by photochemically driven colloidal synthesis, including decahedra, tetrahedra and bi-tetrahedra are investigated. A mismatch of measured and simulated spectra is found in some cases when assuming pure silver particles, which is explained by the presence of a few atomic layers of tarnish on the surface, not evident in electron tomography. The presented method tightens the link between particle morphology and optical response, supporting the predictive design of plasmonic nanomaterials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000828704000001 |
Publication Date |
2022-07-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.7 |
Times cited |
1 |
Open Access |
OpenAccess |
Notes |
Z.S. acknowledges the UK Engineering and Physical Sciences Research Council (EPSRC) for his Ph.D. studentship award (grant EP/R513003/1). Y.W. acknowledges Iwan Moreels (University of Ghent) for training in nanoparticle synthesis. Y.W. acknowledges the Biotechnology and Biological Sciences Research Council (BBSRC) for his Ph.D. studentship award (grant BB/L015889/1). This work was supported by the UK EPSRC (grants EP/I005072/1 and EP/M028313/1), and by the European Commission (EUSMI E191000350). W.A. acknowledges an Individual Fellowship from the Marie Skodowska-Curie actions (MSCA) under the EU's Horizon 2020 program (Grant 797153, SOPMEN). We thank Lukas Payne and Iestyn Pope for contributions to the development of the hardware and software used for the optical measurements. |
Approved |
Most recent IF: 6.7 |
Call Number |
UA @ admin @ c:irua:189578 |
Serial |
7092 |
Permanent link to this record |