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	Author	Geerts, L.; Geerts-Claes, H.; Skorikov, A.; Vermeersch, J.; Vanbutsele, G.; Galvita, V.; Constales, D.; Chandran, C.V.; Radhakrishnan, S.; Seo, J.W.; Breynaert, E.; Bals, S.; Sree, S.P.; Martens, J.A.
	Title	Spherical core–shell alumina support particles for model platinum catalysts			Type	A1 Journal article
	Year	2021	Publication	Nanoscale	Abbreviated Journal	Nanoscale
	Volume	13	Issue	7	Pages	4221-4232
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	γ- and δ-alumina are popular catalyst support materials. Using a hydrothermal synthesis method starting from aluminum nitrate and urea in diluted solution, spherical core–shell particles with a uniform particle size of about 1 μm were synthesized. Upon calcination at 1000 °C, the particles adopted a core–shell structure with a γ-alumina core and δ-alumina shell as evidenced by 2D and 3D electron microscopy and<sup>27</sup>Al magic angle spinning nuclear magnetic resonance spectroscopy. The spherical alumina particles were loaded with Pt nanoparticles with an average size below 1 nm using the strong electrostatic adsorption method. Electron microscopy and energy dispersive X-ray spectroscopy revealed a homogeneous platinum dispersion over the alumina surface. These platinum loaded alumina spheres were used as a model catalyst for bifunctional catalysis. Physical mixtures of Pt/alumina spheres and spherical zeolite particles are equivalent to catalysts with platinum deposited on the zeolite itself facilitating the investigation of the catalyst components individually. The spherical alumina particles are very convenient supports for obtaining a homogeneous distribution of highly dispersed platinum nanoparticles. Obtaining such a small Pt particle size is challenging on other support materials such as zeolites. The here reported and well-characterized Pt/alumina spheres can be combined with any zeolite and used as a bifunctional model catalyst. This is an interesting strategy for the examination of the acid catalytic function without the interference of the supported platinum metal on the investigated acid material.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000621767000026	Publication Date	2021-01-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	7.367	Times cited	3	Open Access	OpenAccess
	Notes	Fonds Wetenschappelijk Onderzoek, G0A5417N G038116N ; Vlaamse regering, Methusalem ; Hercules Foundation, AKUL/13/19 ;			Approved	Most recent IF: 7.367
	Call Number	EMAT @ emat @c:irua:176021			Serial	6679
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	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.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000628024200011	Publication Date	2021-02-22
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		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
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	Author	Skorikov, A.; Heyvaert, W.; Albecht, W.; Pelt, D.M.; Bals, S.
	Title	Deep learning-based denoising for improved dose efficiency in EDX tomography of nanoparticles			Type	A1 Journal article
	Year	2021	Publication	Nanoscale	Abbreviated Journal	Nanoscale
	Volume	13	Issue		Pages	12242-12249
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	The combination of energy-dispersive X-ray spectroscopy (EDX) and electron tomography is a powerful approach to retrieve the 3D elemental distribution in nanomaterials, providing an unprecedented level of information for complex, multi-component systems, such as semiconductor devices, as well as catalytic and plasmonic nanoparticles. Unfortunately, the applicability of EDX tomography is severely limited because of extremely long acquisition times and high electron irradiation doses required to obtain 3D EDX reconstructions with an adequate signal-to-noise ratio. One possibility to address this limitation is intelligent denoising of experimental data using prior expectations about the objects of interest. Herein, this approach is followed using the deep learning methodology, which currently demonstrates state-of-the-art performance for an increasing number of data processing problems. Design choices for the denoising approach and training data are discussed with a focus on nanoparticle-like objects and extremely noisy signals typical for EDX experiments. Quantitative analysis of the proposed method demonstrates its significantly enhanced performance in comparison to classical denoising approaches. This allows for improving the tradeoff between the reconstruction quality, acquisition time and radiation dose for EDX tomography. The proposed method is therefore especially beneficial for the 3D EDX investigation of electron beam-sensitive materials and studies of nanoparticle transformations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000671395800001	Publication Date	2021-07-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	7.367	Times cited	11	Open Access	OpenAccess
	Notes	Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 016.Veni.192.235 ; H2020 European Research Council, 815128 ; H2020 Marie Skłodowska-Curie Actions, 797153 ; H2020 Research Infrastructures, 731019; realnano; sygmaSB			Approved	Most recent IF: 7.367
	Call Number	EMAT @ emat @c:irua:179756			Serial	6799
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	Author	Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P.
	Title	Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters			Type	A1 Journal article
	Year	2021	Publication	Nanoscale	Abbreviated Journal	Nanoscale
	Volume	12	Issue	23	Pages	10462-10467
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin-orbit coupling, which in turn shortens the fluorescence decay lifetime (tau(PL)). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased tau(PL) upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in tau(PL) is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000657052500001	Publication Date	2021-06-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	7.367	Times cited	1	Open Access	OpenAccess
	Notes	The authors acknowledge support from GACR project no. 18-12533S. G. P. acknowledges support from EUSMI project no. E180200060; J. P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066).			Approved	Most recent IF: 7.367
	Call Number	UA @ admin @ c:irua:179052			Serial	6843
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	Author	Pramanik, G.; Kvakova, K.; Thottappali, M.A.; Rais, D.; Pfleger, J.; Greben, M.; El-Zoka, A.; Bals, S.; Dracinsky, M.; Valenta, J.; Cigler, P.
	Title	Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters			Type	A1 Journal Article
	Year	2021	Publication	Nanoscale	Abbreviated Journal	Nanoscale
	Volume	13	Issue	23	Pages	10462-10467
	Keywords	A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
	Abstract	Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin–orbit coupling, which in turn shortens the fluorescence decay lifetime (<italic>τ</italic><sup>PL</sup>). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased<italic>τ</italic><sup>PL</sup>upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in<italic>τ</italic><sup>PL</sup>is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos		Publication Date	2021-05-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links
	Impact Factor	7.367	Times cited	7	Open Access	OpenAccess
	Notes	The authors acknowledge support from GACR project Nr.18- 12533S. G. P. acknowledges support from EUSMI project No. E180200060; J.P. from the Ministry of Education, Youth and Sports of the Czech Republic – Program INTER-EXCELLENCE (LTAUSA19066).			Approved	Most recent IF: 7.367
	Call Number	EMAT @ emat @			Serial	6950
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	Author	Fatermans, J.; Romolini, G.; Altantzis, T.; Hofkens, J.; Roeffaers, M.B.J.; Bals, S.; Van Aert, S.
	Title	Atomic-scale detection of individual lead clusters confined in Linde Type A zeolites			Type	A1 Journal article
	Year	2022	Publication	Nanoscale	Abbreviated Journal	Nanoscale
	Volume		Issue		Pages
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
	Abstract	Structural analysis of metal clusters confined in nanoporous materials is typically performed by X-ray-driven techniques. Although X-ray analysis has proved its strength in the characterization of metal clusters, it provides averaged structural information. Therefore, we here present an alternative workflow for bringing the characterization of confined metal clusters towards the local scale. This workflow is based on the combination of aberration-corrected transmission electron microscopy (TEM), TEM image simulations, and powder X-ray diffraction (XRD) with advanced statistical techniques. In this manner, we were able to characterize the clustering of Pb atoms in Linde Type A (LTA) zeolites with Pb loadings as low as 5 wt%. Moreover, individual Pb clusters could be directly detected. The proposed methodology thus enables a local-scale characterization of confined metal clusters in zeolites. This is important for further elucidation of the connection between the structure and the physicochemical properties of such systems.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000809619900001	Publication Date	0000-00-00
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.7	Times cited	2	Open Access	OpenAccess
	Notes	The authors acknowledge the Research Foundation Flanders through project fundings (FWO, G026718N, G050218N, ZW15_09-G0H6316N, and W002221N) and through a PhD scholarship to G.R. (grant 11C6920N), as well as iBOF-21-085 PERSIST. T.A. and S.V.A. acknowledge funding from the University of Antwerp Research fund (BOF). J.H. acknowledges the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the MPI as MPI fellow. M.R. acknowledges funding by the KU Leuven Research Fund (C14/19/079). S.B. and S.V.A. acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128−REALNANO and No. 770887−PICOMETRICS). The authors thank Dr. D. Chernyshov for the collection of XRD measurements.			Approved	Most recent IF: 6.7
	Call Number	EMAT @ emat @c:irua:189061			Serial	7076
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	Author	Craig, T.M.; Kadu, A.A.; Batenburg, K.J.; Bals, S.
	Title	Real-time tilt undersampling optimization during electron tomography of beam sensitive samples using golden ratio scanning and RECAST3D			Type	A1 Journal article
	Year	2023	Publication	Nanoscale	Abbreviated Journal
	Volume	15	Issue	11	Pages	5391-5402
	Keywords	A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
	Abstract	Electron tomography is a widely used technique for 3D structural analysis of nanomaterials, but it can cause damage to samples due to high electron doses and long exposure times. To minimize such damage, researchers often reduce beam exposure by acquiring fewer projections through tilt undersampling. However, this approach can also introduce reconstruction artifacts due to insufficient sampling. Therefore, it is important to determine the optimal number of projections that minimizes both beam exposure and undersampling artifacts for accurate reconstructions of beam-sensitive samples. Current methods for determining this optimal number of projections involve acquiring and post-processing multiple reconstructions with different numbers of projections, which can be time-consuming and requires multiple samples due to sample damage. To improve this process, we propose a protocol that combines golden ratio scanning and quasi-3D reconstruction to estimate the optimal number of projections in real-time during a single acquisition. This protocol was validated using simulated and realistic nanoparticles, and was successfully applied to reconstruct two beam-sensitive metal–organic framework complexes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000937908900001	Publication Date	2023-02-13
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2040-3364	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.7	Times cited	1	Open Access	OpenAccess
	Notes	H2020 European Research Council, 815128 ; H2020 Marie Skłodowska-Curie Actions, 860942 ;			Approved	Most recent IF: 6.7; 2023 IF: 7.367
	Call Number	EMAT @ emat @c:irua:195235			Serial	7260
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