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Records |
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Author |
de la Croix, T.; Claes, N.; Eyley, S.; Thielemans, W.; Bals, S.; De Vos, D. |
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Title |
Heterogeneous Pt-catalyzed transfer dehydrogenation of long-chain alkanes with ethylene |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
Catalysis Science & Technology |
Abbreviated Journal |
Catal. Sci. Technol. |
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Volume |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
The dehydrogenation of long-chain alkanes to olefins and alkylaromatics is a challenging endothermic reaction, typically requiring harsh conditions which can lead to low selectivity and coking. More favorable thermodynamics can be achieved by using a hydrogen acceptor, such as ethylene. In this work, the potential of heterogeneous platinum catalysts for the transfer dehydrogenation of long-chain alkanes is investigated, using ethylene as a convenient hydrogen acceptor. Pt/C and Pt–Sn/C catalysts were prepared<italic>via</italic>a simple polyol method and characterized with CO pulse chemisorption, HAADF-STEM, and EDX measurements. Conversion of ethylene was monitored<italic>via</italic>gas-phase FTIR, and distribution of liquid products was analyzed<italic>via</italic>GC-FID, GC-MS, and 1H-NMR. Compared to unpromoted Pt/C, Sn-promoted catalysts show lower initial reaction rates, but better resistance to catalyst deactivation, while increasing selectivity towards alkylaromatics. Both reaction products and ethylene were found to inhibit the reaction significantly. At 250 °C for 22 h, TON up to 28 and 86 mol per mol Pt were obtained for Pt/C and PtSn<sub>2</sub>/C, respectively, with olefin selectivities of 94% and 53%. The remaining products were mainly unbranched alkylaromatics. These findings show the potential of simple heterogeneous catalysts in alkane transfer dehydrogenation, for the preparation of valuable olefins and alkylaromatics, or as an essential step in various tandem reactions. |
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Place of Publication |
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Wos |
001104905100001 |
Publication Date |
2023-11-09 |
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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 |
2044-4753 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
5 |
Times cited  |
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Open Access |
OpenAccess |
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Notes |
T. de la Croix gratefully acknowledges the support of the Flanders Research Foundation (FWO) under project 11F6622N. D. De Vos is grateful to FWO for support of project G0D3721N, and to KU Leuven for the iBOF project 21/016/C3. S. Bals and N. Claes acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grant No. 815128- REALNANO). W. Thielemans and S. Eyley thank KU Leuven (grant C14/18/061) and FWO (G0A1219N) for financial support. |
Approved |
Most recent IF: 5; 2023 IF: 5.773 |
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Call Number |
EMAT @ emat @c:irua:201010 |
Serial |
8968 |
| Permanent link to this record |
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Author |
Claes, J.; Partoens, B.; Lamoen, D. |
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Title |
Decoupled DFT-1/2 method for defect excitation energies |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys. Rev. B |
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Volume |
108 |
Issue |
12 |
Pages |
125306 |
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Keywords |
A1 Journal Article; Condensed Matter Theory (CMT) ; |
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Abstract |
The DFT-1/2 method is a band-gap correction with GW precision at a density functional theory (DFT) computational cost. The method was also extended to correct the gap between defect levels, allowing for the calculation of optical transitions. However, this method fails when the atomic character of the occupied and unoccupied defect levels is similar as we illustrate by two examples, the tetrahedral hydrogen interstitial and the negatively charged vacancy in diamond. We solve this problem by decoupling the effect of the occupied and unoccupied defect levels and call this the decoupled DFT-1/2 method for defects. |
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Wos |
001089302800003 |
Publication Date |
2023-09-25 |
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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 |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
This work was supported by the FWO (Research Foundation-Flanders), Project No. G0D1721N. This work was performed in part using HPC resources from the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government department EWI (Economie, Wetenschap & Innovatie). |
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:201287 |
Serial |
8976 |
| Permanent link to this record |
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Author |
Bogaerts, A. |
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Title |
Special Issue on “Dielectric Barrier Discharges and their Applications” in Commemoration of the 20th Anniversary of Dr. Ulrich Kogelschatz’s Work |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
Plasma Chemistry and Plasma Processing |
Abbreviated Journal |
Plasma Chem Plasma Process |
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Volume |
43 |
Issue |
6 |
Pages |
1281-1285 |
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Keywords |
A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
n/a |
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Wos |
001110371000001 |
Publication Date |
2023-11-30 |
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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 |
0272-4324 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.6 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
n/a |
Approved |
Most recent IF: 3.6; 2023 IF: 2.355 |
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Call Number |
PLASMANT @ plasmant @c:irua:201387 |
Serial |
8969 |
| Permanent link to this record |
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Author |
Lin, A.; Gromov, M.; Nikiforov, A.; Smits, E.; Bogaerts, A. |
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Title |
Characterization of Non-Thermal Dielectric Barrier Discharges for Plasma Medicine: From Plastic Well Plates to Skin Surfaces |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
Plasma Chemistry and Plasma Processing |
Abbreviated Journal |
Plasma Chem Plasma Process |
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Volume |
43 |
Issue |
6 |
Pages |
1587-1612 |
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Keywords |
A1 Journal Article; Non-thermal plasma · Plasma medicine · Dielectric barrier discharge · Plasma diagnostics · Plasma surface interaction · In situ plasma monitoring; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
technologies have been expanding, and one of the most exciting and rapidly growing
applications is in biology and medicine. Most biomedical studies with DBD plasma systems are performed in vitro, which include cells grown on the surface of plastic well plates, or in vivo, which include animal research models (e.g. mice, pigs). Since many DBD systems use the biological target as the secondary electrode for direct plasma generation and treatment, they are sensitive to the surface properties of the target, and thus can be altered based on the in vitro or in vivo system used. This could consequently affect biological response from plasma treatment. Therefore, in this study, we investigated the DBD plasma behavior both in vitro (i.e. 96-well flat bottom plates, 96-well U-bottom plates, and 24-well flat bottom plates), and in vivo (i.e. mouse skin). Intensified charge coupled device (ICCD) imaging was performed and the plasma discharges were visually distinguishable between the different systems. The geometry of the wells did not affect DBD plasma generation for low application distances (≤ 2 mm), but differentially affected plasma uniformity on the bottom of the well at greater distances. Since DBD plasma treatment in vitro is rarely performed in dry wells for plasma medicine experiments, the effect of well wetness was also investigated. In all in vitro cases, the uniformity of the DBD plasma was affected when comparing wet versus dry wells, with the plasma in the wide-bottom wells appearing the most similar to plasma generated on mouse skin. Interestingly, based on quantification of ICCD images, the DBD plasma intensity per surface area demonstrated an exponential one-phase decay with increasing application distance, regardless of the in vitro or in vivo system. This trend is similar to that of the energy per pulse of plasma, which is used to determine the total plasma treatment energy for biological systems. Optical emission spectroscopy performed on the plasma revealed similar trends in radical species generation between the plastic well plates and mouse skin. Therefore, taken together, DBD plasma intensity per surface area may be a valuable parameter to be used as a simple method for in situ monitoring during biological treatment and active plasma treatment control, which can be applied for in vitro and in vivo systems. |
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Wos |
001072607700001 |
Publication Date |
2023-09-27 |
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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 |
0272-4324 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.6 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
This work was partially funded by the Research Foundation—Flanders (FWO) and supported by the following Grants: 12S9221N (A. L.), G044420N (A. L. and A. B.), and G033020N (A.B.). We would also like to thank several patrons, as part of this research was funded by donations from different donors, including Dedert Schilde vzw, Mr Willy Floren, and the Vereycken family. We would also like to acknowledge the support from the European Cooperation in Science & Technology (COST) Action on “Therapeutical applications of Cold Plasmas” (CA20114; PlasTHER). |
Approved |
Most recent IF: 3.6; 2023 IF: 2.355 |
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Call Number |
PLASMANT @ plasmant @c:irua:200285 |
Serial |
8970 |
| Permanent link to this record |
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Author |
Slaets, J.; Loenders, B.; Bogaerts, A. |
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Title |
Plasma-based dry reforming of CH4: Plasma effects vs. thermal conversion |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Fuel |
Abbreviated Journal |
Fuel |
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Volume |
360 |
Issue |
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Pages |
130650 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
In this work we evaluate the chemical kinetics of dry reforming of methane in warm plasmas (1000–4000 K) using modelling with a newly developed chemistry set, for a broad range of parameters (temperature, power density and CO2/CH4 ratio). We compare the model against thermodynamic equilibrium concentrations, serving as validation of the thermal chemical kinetics. Our model reveals that plasma-specific reactions (i.e., electron impact collisions) accelerate the kinetics compared to thermal conversion, rather than altering the overall kinetics pathways and intermediate products, for gas temperatures below 2000 K. For higher temperatures, the kinetics are dominated by heavy species collisions and are strictly thermal, with negligible influence of the electrons and ions on the overall kinetics. When studying the effects of different gas mixtures on the kinetics, we identify important intermediate species, side reactions and side products. The use of excess CO2 leads to H2O formation, at the expense of H2 formation, and the CO2 conversion itself is limited, only approaching full conversion near 4000 K. In contrast, full conversion of both reactants is only kinetically limited for mixtures with excess CH4, which also gives rise to the formation of C2H2, alongside syngas. Within the given parameter space, our model predicts the 30/70 ratio of CO2/CH4 to be the most optimal for syngas formation with a H2/CO ratio of 2. |
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Wos |
001138077700001 |
Publication Date |
2023-12-15 |
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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 |
0016-2361 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.4 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
This research was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 810182 – SCOPE ERC Synergy project), the Catalisti-ICON project BluePlasma (Project No. HBC.2022.0445), the FWO-SBO project PlasMaCatDESIGN (FWO Grant ID S001619N), the Independent Research Fund Denmark (Project No. 0217-00231B) and through long-term structural funding (Methusalem). The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government. We also thank Bart Wanten, Roel Michiels, Pepijn Heirman, Claudia Verheyen, dr. Senne Van Alphen, dr. Elise Vervloessem, dr. Kevin van ’t Veer, dr. Joshua Boothroyd, dr. Omar Biondo and dr. Eduardo Morais for their expertise and feedback regarding the kinetics scheme. |
Approved |
Most recent IF: 7.4; 2024 IF: 4.601 |
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Call Number |
PLASMANT @ plasmant @c:irua:201669 |
Serial |
8973 |
| Permanent link to this record |
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Author |
Bhatia, H.; Keshavarz, M.; Martin, C.; Van Gaal, L.; Zhang, Y.; de Coen, B.; Schrenker, N.J.; Valli, D.; Ottesen, M.; Bremholm, M.; Van de Vondel, J.; Bals, S.; Hofkens, J.; Debroye, E. |
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Title |
Achieving High Moisture Tolerance in Pseudohalide Perovskite Nanocrystals for Light-Emitting Diode Application |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
ACS Applied Optical Materials |
Abbreviated Journal |
ACS Appl. Opt. Mater. |
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Volume |
1 |
Issue |
6 |
Pages |
1184-1191 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
The addition of potassium thiocyanate (KSCN) to the FAPbBr3 structure and subsequent post-treatment of nanocrystals (NCs) lead to high quantum confinement, resulting in a photoluminescent quantum yield (PLQY) approaching unity and microsecond decay times. This synergistic approach demonstrated exceptional stability under humid conditions, retaining 70% of the PLQY for over a month, while the untreated NCs degrade within 24 h. Additionally, the devices incorporating the post-treated NCs displayed 1.5% external quantum efficiency (EQE), a 5-fold improvement over untreated devices. These results provide promising opportunities for the use of perovskites in moisture-stable optoelectronics. |
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Wos |
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Publication Date |
2023-06-23 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2771-9855 |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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Notes |
Hercules Foundation, HER/11/14 ; European Commission; Ministerio de Ciencia e Innovaci?n, PID2021-128761OA-C22 ; European Regional Development Fund; Vlaamse regering, CASAS2 Meth/15/04 ; Fonds Wetenschappelijk Onderzoek, 1238622N 1514220N 1S45223N G.0B39.15 G.0B49.15 G098319N S002019N ZW15_09-GOH6316 ; Onderzoeksraad, KU Leuven, C14/19/079 db/21/006/bm iBOF-21-085 STG/21/010 ; Junta de Comunidades de Castilla-La Mancha, SBPLY/21/180501/000127 ; H2020 European Research Council, 642196 815128 ; |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @c:irua:201011 |
Serial |
8975 |
| Permanent link to this record |
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Author |
Delfino, C.L.; Hao, Y.; Martin, C.; Minoia, A.; Gopi, E.; Mali, K.S.; Van der Auweraer, M.; Geerts, Y.H.; Van Aert, S.; Lazzaroni, R.; De Feyter, S. |
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Title |
Conformation-Dependent Monolayer and Bilayer Structures of an Alkylated TTF Derivative Revealed using STM and Molecular Modeling |
Type |
A1 Journal Article |
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Year |
2023 |
Publication |
The Journal of Physical Chemistry C |
Abbreviated Journal |
J. Phys. Chem. C |
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Volume |
127 |
Issue |
47 |
Pages |
23023-23033 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
In this study, the multi-layer self-assembled molecular network formation of an alkylated tetrathiafulvalene compound is studied at the liquid-solid interface between 1-phenyloctane and graphite. A combined theoretical/experimental approach associating force-field and quantum-chemical calculations with scanning tunnelling microscopy is used to determine the two-dimensional self-assembly beyond the monolayer, but also to further the understanding of the molecular adsorption conformation and its impact on the molecular packing within the assemblies at the monolayer and bilayer level. |
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Wos |
001111637100001 |
Publication Date |
2023-11-30 |
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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 |
1932-7447 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
Financial support from the Research Foundation-Flanders (FWO G081518N, G0A3220N) and KU Leuven–Internal Funds (C14/19/079) is acknowledged. This work was in part supported by FWO and F. R. S.-FNRS under the Excellence of Science EOS program (project 30489208 and 40007495). C.M. acknowledges the financial support: Grants PID2021-128761OA-C22 and CNS2022-136052 funded by MCIN/AEI/10.13039/501100011033 by the “European Union” and SBPLY/21/180501/000127 funded by JCCM and by the EU through “Fondo Europeo de Desarollo Regional” (FEDER). Research in Mons is also supported by the Belgian National Fund for Scientific Research (FRS-FNRS) within the Consortium des Équipements de Calcul Intensif – CÉCI, under Grant 2.5020.11, and by the Walloon Region (ZENOBE Tier-1 supercomputer, under grant 1117545). |
Approved |
Most recent IF: 3.7; 2023 IF: 4.536 |
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Call Number |
EMAT @ emat @c:irua:201671 |
Serial |
8974 |
| Permanent link to this record |
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Author |
Grünewald, L.; Chezganov, D.; De Meyer, R.; Orekhov, A.; Van Aert, S.; Bogaerts, A.; Bals, S.; Verbeeck, J. |
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Title |
In Situ Plasma Studies Using a Direct Current Microplasma in a Scanning Electron Microscope |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Advanced Materials Technologies |
Abbreviated Journal |
Adv Materials Technologies |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Microplasmas can be used for a wide range of technological applications and to improve the understanding of fundamental physics. Scanning electron microscopy, on the other hand, provides insights into the sample morphology and chemistry of materials from the mm‐ down to the nm‐scale. Combining both would provide direct insight into plasma‐sample interactions in real‐time and at high spatial resolution. Up till now, very few attempts in this direction have been made, and significant challenges remain. This work presents a stable direct current glow discharge microplasma setup built inside a scanning electron microscope. The experimental setup is capable of real‐time in situ imaging of the sample evolution during plasma operation and it demonstrates localized sputtering and sample oxidation. Further, the experimental parameters such as varying gas mixtures, electrode polarity, and field strength are explored and experimental<italic>V</italic>–<italic>I</italic>curves under various conditions are provided. These results demonstrate the capabilities of this setup in potential investigations of plasma physics, plasma‐surface interactions, and materials science and its practical applications. The presented setup shows the potential to have several technological applications, for example, to locally modify the sample surface (e.g., local oxidation and ion implantation for nanotechnology applications) on the µm‐scale. |
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Wos |
001168639900001 |
Publication Date |
2024-02-25 |
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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 |
2365-709X |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
6.8 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
L.G., S.B., and J.V. acknowledge support from the iBOF-21-085 PERsist research fund. D.C., S.V.A., and J.V. acknowledge funding from a TOPBOF project of the University of Antwerp (FFB 170366). R.D.M., A.B., and J.V. acknowledge funding from the Methusalem project of the University of Antwerp (FFB 15001A, FFB 15001C). A.O. and J.V. acknowledge funding from the Research Foundation Flanders (FWO, Belgium) project SBO S000121N. |
Approved |
Most recent IF: 6.8; 2024 IF: NA |
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Call Number |
EMAT @ emat @c:irua:204363 |
Serial |
8995 |
| Permanent link to this record |
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Author |
Şentürk, D.G.; De Backer, A.; Van Aert, S. |
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Title |
Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
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Volume |
259 |
Issue |
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Pages |
113941 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy. |
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Wos |
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Publication Date |
2024-02-19 |
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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 |
0304-3991 |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
2.2 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). |
Approved |
Most recent IF: 2.2; 2024 IF: 2.843 |
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Call Number |
EMAT @ emat @c:irua:204353 |
Serial |
8996 |
| Permanent link to this record |
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Author |
Vandemeulebroucke, D.; Batuk, M.; Hajizadeh, A.; Wastiaux, M.; Roussel, P.; Hadermann, J. |
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Title |
Incommensurate Modulations and Perovskite Growth in LaxSr2–xMnO4−δAffecting Solid Oxide Fuel Cell Conductivity |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Chemistry of Materials |
Abbreviated Journal |
Chem. Mater. |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Ruddlesden-Popper La????Sr2−????MnO4−???? materials are interesting symmetric solid oxide
fuel cell electrodes due to their good redox stability, mixed ionic and electronic conducting behavior and thermal expansion that matches well with common electrolytes. In reducing environments – as at a solid oxide fuel cell anode – the x = 0.5 member, i.e. La0.5Sr1.5MnO4−????, has a much higher total conductivity than compounds with a different La/Sr ratio, although all those compositions have the same K2NiF4-type I4/mmm structure. The origin for this conductivity difference is not yet known in literature. Now, a combination of in-situ and ex-situ 3D electron diffraction, high-resolution imaging, energy-dispersive X-ray analysis and electron energy-loss spectroscopy uncovered clear differences between x=0.25 and x=0.5 in the pristine structure, as well as in the transformations upon high-temperature reduction. In La0.5Sr1.5MnO4−????, Ruddlesden-Popper n=2 layer defects and an amorphous surface layer are present, but not in La0.25Sr1.75MnO4−????. After annealing at 700°C in 5% H2/Ar, La0.25Sr1.75MnO4−???? transforms to a tetragonal 2D incommensurately modulated structure with modulation vectors ⃗????1 = 0.2848(1) · (⃗????* +⃗????*) and ⃗????2 =0.2848(1) · (⃗????* – ⃗????*), whereas La0.5Sr1.5MnO4−???? only partially transforms to an orthorhombic 1D incommensurately modulated structure,
with ⃗???? = 0.318(2) · ⃗????*. Perovskite domains grow at the crystal edge at 700°C in 5%
H2 or vacuum, due to the higher La concentration on the surface compared to the bulk, which leads to a different thermodynamic equilibrium. Since it is known that a lower degree of oxygen vacancy ordering and a higher amount of perovskite blocks enhance oxygen mobility, those differences in defect structure and structural transformation upon reduction, might all contribute to the higher conductivity of La0.5Sr1.5MnO4−???? in solid oxide fuel cell anode conditions compared to other La/Sr ratios. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
English |
Wos |
001174840900001 |
Publication Date |
2024-02-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| |
Impact Factor |
8.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| |
Notes |
Universiteit Antwerpen, BOF TOP 38689 ; Fonds Wetenschappelijk Onderzoek, I003218N ; European Commission NanED, 956099 ; |
Approved |
Most recent IF: 8.6; 2024 IF: 9.466 |
| |
Call Number |
EMAT @ emat @c:irua:204354 |
Serial |
8997 |
| Permanent link to this record |
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Author |
Mayda, S.; Monico, L.; Krishnan, D.; De Meyer, S.; Cotte, M.; Garrevoet, J.; Falkenberg, G.; Sandu, I.C.A.; Partoens, B.; Lamoen, D.; Romani, A.; Miliani, C.; Verbeeck, J.; Janssens, K. |
| |
Title |
A combined experimental and computational approach to understanding CdS pigment oxidation in a renowned early 20th century painting |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Chemistry of materials |
Abbreviated Journal |
|
| |
Volume |
35 |
Issue |
24 |
Pages |
10403-10415 |
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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Abstract |
Cadmium sulfide (CdS)-based yellow pigments have been used in a number of early 20th century artworks, including The Scream series painted by Edvard Munch. Some of these unique paintings are threatened by the discoloration of these CdS-based yellow oil paints because of the oxidation of the original sulfides to sulfates. The experimental data obtained here prove that moisture and cadmium chloride compounds play a key role in promoting such oxidation. To clarify how these two factors effectively prompt the process, we studied the band alignment between CdS, CdCl2, and Cd-(OH)Cl as well as the radicals center dot OH and H3O center dot by density functional theory (DFT) methods. Our results show that a stack of several layers of Cd-(OH)Cl creates a pocket of positive holes at the Cl-terminated surface and a pocket of electrons at the OH-terminated surface by leading in a difference in ionization energy at both surfaces. The resulting band alignment indicates that Cd-(OH)Cl can indeed play the role of an oxidative catalyst for CdS in a moist environment, thus providing an explanation for the experimental evidence. |
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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 |
001133000900001 |
Publication Date |
2023-12-08 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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ISSN |
0897-4756; 1520-5002 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
8.6 |
Times cited |
|
Open Access |
|
| |
Notes |
The experimental research on the cadmium yellow powders/paint mock-ups and The Scream (ca. 1910) was financially supported by the European Union, research projects IPERION-CH (H2020-INFRAIA-2014-2015, GA no. 654028) and IPERION-HS (H2020-INFRAIA-2019-1, GA no. 871034) and the project AMIS within the program Dipartimenti di Eccellenza 2018-2022 (funded by MUR and the University of Perugia). For the beamtime grants received, the authors thank the ESRF-ID21 beamline (experiments HG64 and HG95), the DESY-P06 beamline, a member of the Helmholtz Association HGF (experiments I-20130221 EC and I-20160126 EC), and the project CALIPSOplus under the GA no. 730872 from the E.U. Framework Programme for Research and Innovation Horizon 2020. All of the staff of the MUNCH Museum (Conservation Department) is acknowledged for their collaboration. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO – Vlaanderen and the Flemish Government, Department EWI. |
Approved |
Most recent IF: 8.6; 2023 IF: 9.466 |
| |
Call Number |
UA @ admin @ c:irua:202836 |
Serial |
8999 |
| Permanent link to this record |
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Author |
Duran, T.A.; Yayak, Y.O.; Aydin, H.; Peeters, F.M.; Yagmurcukardes, M. |
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Title |
A perspective on the state-of-the-art functionalized 2D materials |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Journal of applied physics |
Abbreviated Journal |
|
| |
Volume |
134 |
Issue |
12 |
Pages |
120901-120929 |
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| |
Abstract |
Two-dimensional (2D) ultra-thin materials are more crucial than their bulk counterparts for the covalent functionalization of their surface owing to atomic thinness, large surface-to-volume ratio, and high reactivity of surface atoms having unoccupied orbitals. Since the surface of a 2D material is composed of atoms having unoccupied orbitals, covalent functionalization enables one to improve or precisely modify the properties of the ultra-thin materials. Chemical functionalization of 2D materials not only modifies their intrinsic properties but also makes them adapted for nanotechnology applications. Such engineered materials have been used in many different applications with their improved properties. In the present Perspective, we begin with a brief history of functionalization followed by the introduction of functionalized 2D materials. Our Perspective is composed of the following sections: the applications areas of 2D graphene and graphene oxide crystals, transition metal dichalcogenides, and in-plane anisotropic black phosphorus, all of which have been widely used in different nanotechnology applications. Finally, our Perspectives on the future directions of applications of functionalized 2D materials are given. The present Perspective sheds light on the current progress in nanotechnological applications of engineered 2D materials through surface functionalization. |
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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 |
001087770500008 |
Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.2 |
Times cited |
|
Open Access |
|
| |
Notes |
|
Approved |
Most recent IF: 3.2; 2023 IF: 2.068 |
| |
Call Number |
UA @ admin @ c:irua:201281 |
Serial |
9000 |
| Permanent link to this record |
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Author |
Jenkinson, K.; Spadaro, M.C.; Golovanova, V.; Andreu, T.; Morante, J.R.; Arbiol, J.; Bals, S. |
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Title |
Direct operando visualization of metal support interactions induced by hydrogen spillover during CO₂ hydrogenation |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Advanced materials |
Abbreviated Journal |
|
| |
Volume |
35 |
Issue |
51 |
Pages |
2306447-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The understanding of catalyst active sites is a fundamental challenge for the future rational design of optimized and bespoke catalysts. For instance, the partial reduction of Ce4+ surface sites to Ce3+ and the formation of oxygen vacancies are critical for CO2 hydrogenation, CO oxidation, and the water gas shift reaction. Furthermore, metal nanoparticles, the reducible support, and metal support interactions are prone to evolve under reaction conditions; therefore a catalyst structure must be characterized under operando conditions to identify active states and deduce structure-activity relationships. In the present work, temperature-induced morphological and chemical changes in Ni nanoparticle-decorated mesoporous CeO2 by means of in situ quantitative multimode electron tomography and in situ heating electron energy loss spectroscopy, respectively, are investigated. Moreover, operando electron energy loss spectroscopy is employed using a windowed gas cell and reveals the role of Ni-induced hydrogen spillover on active Ce3+ site formation and enhancement of the overall catalytic performance. |
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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 |
001106139400001 |
Publication Date |
2023-10-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
29.4 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 29.4; 2023 IF: 19.791 |
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Call Number |
UA @ admin @ c:irua:201143 |
Serial |
9022 |
| Permanent link to this record |
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Author |
Huang, S.; Griffin, E.; Cai, J.; Xin, B.; Tong, J.; Fu, Y.; Kravets, V.; Peeters, F.M.; Lozada-Hidalgo, M. |
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Title |
Gate-controlled suppression of light-driven proton transport through graphene electrodes |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Nature communications |
Abbreviated Journal |
|
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Volume |
14 |
Issue |
1 |
Pages |
6932-6937 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Recent experiments demonstrated that proton transport through graphene electrodes can be accelerated by over an order of magnitude with low intensity illumination. Here we show that this photo-effect can be suppressed for a tuneable fraction of the infra-red spectrum by applying a voltage bias. Using photocurrent measurements and Raman spectroscopy, we show that such fraction can be selected by tuning the Fermi energy of electrons in graphene with a bias, a phenomenon controlled by Pauli blocking of photo-excited electrons. These findings demonstrate a dependence between graphene's electronic and proton transport properties and provide fundamental insights into molecularly thin electrode-electrolyte interfaces and their interaction with light. Recent experiments have shown that proton transport through graphene electrodes can be promoted by light, but the understanding of this phenomenon remains unclear. Here, the authors report the electrical tunability of this photo-effect, showing a connection between graphene electronic and proton transport properties. |
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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 |
001094448600003 |
Publication Date |
2023-10-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
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ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| |
Impact Factor |
16.6 |
Times cited |
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Open Access |
|
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Notes |
|
Approved |
Most recent IF: 16.6; 2023 IF: 12.124 |
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Call Number |
UA @ admin @ c:irua:201185 |
Serial |
9041 |
| Permanent link to this record |
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Author |
Van den Hoek, J.; Daems, N.; Arnouts, S.; Hoekx, S.; Bals, S.; Breugelmans, T. |
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Title |
Improving stability of CO₂ electroreduction by incorporating Ag NPs in N-doped ordered mesoporous carbon structures |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
ACS applied materials and interfaces |
Abbreviated Journal |
|
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Volume |
16 |
Issue |
6 |
Pages |
6931-6947 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) |
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Abstract |
The electroreduction of carbon dioxide (eCO2RR) to CO using Ag nanoparticles as an electrocatalyst is promising as an industrial carbon capture and utilization (CCU) technique to mitigate CO2 emissions. Nevertheless, the long-term stability of these Ag nanoparticles has been insufficient despite initial high Faradaic efficiencies and/or partial current densities. To improve the stability, we evaluated an up-scalable and easily tunable synthesis route to deposit low-weight percentages of Ag nanoparticles (NPs) on and into the framework of a nitrogen-doped ordered mesoporous carbon (NOMC) structure. By exploiting this so-called nanoparticle confinement strategy, the nanoparticle mobility under operation is strongly reduced. As a result, particle detachment and agglomeration, two of the most pronounced electrocatalytic degradation mechanisms, are (partially) blocked and catalyst durability is improved. Several synthesis parameters, such as the anchoring agent, the weight percentage of Ag NPs, and the type of carbonaceous support material, were modified in a controlled manner to evaluate their respective impact on the overall electrochemical performance, with a strong emphasis on operational stability. The resulting powders were evaluated through electrochemical and physicochemical characterization methods, including X-ray diffraction (XRD), N2-physisorption, Inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), SEM-energy-dispersive X-ray spectroscopy (SEM-EDS), high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM-EDS, electron tomography, and X-ray photoelectron spectroscopy (XPS). The optimized Ag/soft-NOMC catalysts showed both a promising selectivity (∼80%) and stability compared with commercial Ag NPs while decreasing the loading of the transition metal by more than 50%. The stability of both the 5 and 10 wt % Ag/soft-NOMC catalysts showed considerable improvements by anchoring the Ag NPs on and into a NOMC framework, resulting in a 267% improvement in CO selectivity after 72 h (despite initial losses) compared to commercial Ag NPs. These results demonstrate the promising strategy of anchoring Ag NPs to improve the CO selectivity during prolonged experiments due to the reduced mobility of the Ag NPs and thus enhanced stability. |
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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 |
001158812100001 |
Publication Date |
2023-12-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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ISSN |
1944-8244 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
9.5 |
Times cited |
|
Open Access |
Not_Open_Access: Available from 21.06.2024 |
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Notes |
|
Approved |
Most recent IF: 9.5; 2024 IF: 7.504 |
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Call Number |
UA @ admin @ c:irua:202309 |
Serial |
9045 |
| Permanent link to this record |
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Author |
Hugenschmidt, M.; Jannis, D.; Kadu, A.A.; Grünewald, L.; De Marchi, S.; Perez-Juste, J.; Verbeeck, J.; Van Aert, S.; Bals, S. |
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Title |
Low-dose 4D-STEM tomography for beam-sensitive nanocomposites |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
ACS materials letters |
Abbreviated Journal |
|
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Volume |
6 |
Issue |
1 |
Pages |
165-173 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Electron tomography is essential for investigating the three-dimensional (3D) structure of nanomaterials. However, many of these materials, such as metal-organic frameworks (MOFs), are extremely sensitive to electron radiation, making it difficult to acquire a series of projection images for electron tomography without inducing electron-beam damage. Another significant challenge is the high contrast in high-angle annular dark field scanning transmission electron microscopy that can be expected for nanocomposites composed of a metal nanoparticle and an MOF. This strong contrast leads to so-called metal artifacts in the 3D reconstruction. To overcome these limitations, we here present low-dose electron tomography based on four-dimensional scanning transmission electron microscopy (4D-STEM) data sets, collected using an ultrafast and highly sensitive direct electron detector. As a proof of concept, we demonstrate the applicability of the method for an Au nanostar embedded in a ZIF-8 MOF, which is of great interest for applications in various fields, including drug delivery. |
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Corporate Author |
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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 |
001141178500001 |
Publication Date |
2023-12-11 |
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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 |
2639-4979 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access |
Not_Open_Access |
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Notes |
This work was supported by the European Research Council (Grant 815128 REALNANO to S.B., Grant 770887 PICOMETRICS to S.V.A.). J.P.-J. and S.M. acknowledge financial support from the MCIN/AEI/10.13039/501100011033 (Grants No. PID2019-108954RB-I00) and EU Horizon 2020 research and innovation program under grant agreement no. 883390 (SERSing). J.V., S.B., S.V.A., and L.G. acknowledge funding from the Flemish government (iBOF-21-085 PERsist). |
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:202771 |
Serial |
9053 |
| Permanent link to this record |
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Author |
Liu, J.; Xu, W.; Xiao, Y.M.; Ding, L.; Li, H.W.; Peeters, F.M. |
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Title |
Optical spectrum of n-type and p-type monolayer MoS₂ in the presence of proximity-induced interactions |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Journal of applied physics |
Abbreviated Journal |
|
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Volume |
134 |
Issue |
22 |
Pages |
224301-224307 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In this paper, we examined the effects of proximity-induced interactions such as Rashba spin-orbit coupling and effective Zeeman fields (EZFs) on the optical spectrum of n-type and p-type monolayer (ML)-MoS2. The optical conductivity is evaluated using the standard Kubo formula under random-phase approximation by including the effective electron-electron interaction. It has been found that there exist two absorption peaks in n-type ML-MoS2 and two knife shaped absorptions in p-type ML-MoS2, which are contributed by the inter-subband spin-flip electronic transitions within conduction and valence bands at valleys K and K ' with a lifted valley degeneracy. The optical absorptions in n-type and p-type ML-MoS 2 occur in THz and infrared radiation regimes and the position, height, and shape of them can be effectively tuned by Rashba parameter, EZF parameters, and carrier density. The interesting theoretical predictions in this study would be helpful for the experimental observation of the optical absorption in infrared to THz bandwidths contributed by inter-subband spin-flip electronic transitions in a lifted valley degeneracy monolayer transition metal dichalcogenides system. The obtained results indicate that ML-MoS2 with the platform of proximity interactions make it a promising infrared and THz material for optics and optoelectronics. |
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Corporate Author |
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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 |
001135684400003 |
Publication Date |
2023-12-11 |
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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 |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.2 |
Times cited |
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Open Access |
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Notes |
|
Approved |
Most recent IF: 3.2; 2023 IF: 2.068 |
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Call Number |
UA @ admin @ c:irua:202777 |
Serial |
9069 |
| Permanent link to this record |
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Author |
Gerrits, N.; Jackson, B.; Bogaerts, A. |
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Title |
Accurate Reaction Probabilities for Translational Energies on Both Sides of the Barrier of Dissociative Chemisorption on Metal Surfaces |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
The Journal of Physical Chemistry Letters |
Abbreviated Journal |
J. Phys. Chem. Lett. |
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Volume |
15 |
Issue |
9 |
Pages |
2566-2572 |
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Keywords |
A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
Molecular dynamics simulations are essential for a better understanding of dissociative chemisorption on metal surfaces, which is often the rate-controlling step in heterogeneous and plasma catalysis. The workhorse quasi-classical trajectory approach ubiquitous in molecular dynamics is able to accurately predict reactivity only for high translational and low vibrational energies. In contrast, catalytically relevant conditions generally involve low translational and elevated vibrational energies. Existing quantum dynamics approaches are intractable or approximate as a result of the large number of degrees of freedom present in molecule−metal surface reactions. Here, we extend a ring polymer molecular dynamics approach to fully include, for the first time, the degrees of freedom of a moving metal surface. With this approach, experimental sticking probabilities for the dissociative chemisorption of methane on Pt(111) are reproduced for a large range of translational and vibrational energies by including nuclear quantum effects and employing full-dimensional simulations. |
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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 |
001177959900001 |
Publication Date |
2024-03-07 |
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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 |
1948-7185 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
5.7 |
Times cited |
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Open Access |
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Notes |
Nick Gerrits has been financially supported through a Dutch Research Council (NWO) Rubicon grant (019.202EN.012). The computational resources and services used in this work were provided by the high performance computing (HPC) core facility CalcUA of the Universiteit Antwerpen and the Flemish Supercomputer Center (VSC) funded by the Research Foundation−Flanders (FWO) and the Flemish Government. The authors thank Mark Somers for useful discussions. |
Approved |
Most recent IF: 5.7; 2024 IF: 9.353 |
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Call Number |
PLASMANT @ plasmant @c:irua:204818 |
Serial |
9114 |
| Permanent link to this record |
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Author |
De Meyer, R.; Gorbanev, Y.; Ciocarlan, R.-G.; Cool, P.; Bals, S.; Bogaerts, A. |
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Title |
Importance of plasma discharge characteristics in plasma catalysis: Dry reforming of methane vs. ammonia synthesis |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Chemical Engineering Journal |
Abbreviated Journal |
Chemical Engineering Journal |
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Volume |
488 |
Issue |
|
Pages |
150838 |
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Keywords |
A1 Journal Article; Gas conversion Dry reforming of methane Ammonia Microdischarges Dielectric barrier discharge; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
Plasma catalysis is a rapidly growing field, often employing a packed-bed dielectric barrier discharge plasma reactor. Such dielectric barrier discharges are complex, especially when a packing material (e.g., a catalyst) is introduced in the discharge volume. Catalysts are known to affect the plasma discharge, though the underlying mechanisms influencing the plasma physics are not fully understood. Moreover, the effect of the catalysts on the plasma discharge and its subsequent effect on the overall performance is often overlooked. In this work, we deliberately design and synthesize catalysts to affect the plasma discharge in different ways. These Ni or Co alumina-based catalysts are used in plasma-catalytic dry reforming of methane and ammonia synthesis. Our work shows that introducing a metal to the dielectric packing can affect the plasma discharge, and that the distribution of the metal is crucial in this regard. Further, the altered discharge can greatly influence the overall performance. In an atmospheric pressure dielectric barrier discharge reactor, this apparently more uniform plasma yields a significantly better performance for ammonia synthesis compared to the more conventional filamentary discharge, while it underperforms in dry reforming of methane. This study stresses the importance of analyzing the plasma discharge in plasma catalysis experiments. We hope this work encourages a more critical view on the plasma discharge characteristics when studying various catalysts in a plasma reactor. |
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Editor |
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Language |
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Wos |
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Publication Date |
2024-03-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1385-8947 |
ISBN |
|
Additional Links |
UA library record |
| |
Impact Factor |
15.1 |
Times cited |
|
Open Access |
|
| |
Notes |
This research was supported through long-term structural funding (Methusalem FFB15001C) and by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme with grant agreement No 810182 (SCOPE ERC Synergy project) and with grant agreement No 815128 (REALNANO). We acknowledge the practical contribution of Senne Van Doorslaer. |
Approved |
Most recent IF: 15.1; 2024 IF: 6.216 |
| |
Call Number |
PLASMANT @ plasmant @c:irua:205154 |
Serial |
9115 |
| Permanent link to this record |
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|
| |
|
Author |
Faraji, F.; Neyts, E.C.; Milošević, M.V.; Peeters, F.M. |
| |
Title |
Comment on “Misinterpretation of the Shuttleworth equation” |
Type |
A1 Journal Article |
| |
Year |
2024 |
Publication |
Scripta Materialia |
Abbreviated Journal |
Scripta Materialia |
| |
Volume |
250 |
Issue |
|
Pages |
116186 |
| |
Keywords |
A1 Journal Article; CMT |
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Abstract |
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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 |
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Publication Date |
2024-05-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
1359-6462 |
ISBN |
|
Additional Links |
|
| |
Impact Factor |
6 |
Times cited |
|
Open Access |
|
| |
Notes |
Research Foundation Flanders; |
Approved |
Most recent IF: 6; 2024 IF: 3.747 |
| |
Call Number |
UA @ lucian @ CMT |
Serial |
9116 |
| Permanent link to this record |
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Author |
Gorbanev, Y.; Fedirchyk, I.; Bogaerts, A. |
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Title |
Plasma catalysis in ammonia production and decomposition: Use it, or lose it? |
Type |
A1 Journal Article |
| |
Year |
2024 |
Publication |
Current Opinion in Green and Sustainable Chemistry |
Abbreviated Journal |
Current Opinion in Green and Sustainable Chemistry |
| |
Volume |
47 |
Issue |
|
Pages |
100916 |
| |
Keywords |
A1 Journal Article; Plasma Nitrogen fixation Ammonia Plasma catalysis Production and decomposition; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
| |
Abstract |
The combination of plasma with catalysis for the synthesis and decomposition of NH3 is an attractive route to the production of carbon-neutral fertiliser and energy carriers and its conversion into H2. Recent years have seen fast developments in the field of plasma-catalytic NH3 life cycle. This work summarises the most recent advances in plasma-catalytic and related NH3-focussed processes, identifies some of the most important discoveries, and addresses plausible strategies for future developments in plasma-based NH3 technology. |
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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 |
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Publication Date |
2024-03-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
2452-2236 |
ISBN |
|
Additional Links |
|
| |
Impact Factor |
9.3 |
Times cited |
|
Open Access |
|
| |
Notes |
The work was supported by the Fund for Scientific Research (FWO) Flanders Bioeconomy project (grant G0G2322N) funded by the European Union-NextGe- nerationEU, the HyPACT project funded by the Belgian Energy Transition Fund, and the MSCA4Ukraine project 1233629 funded by the European Union. |
Approved |
Most recent IF: 9.3; 2024 IF: NA |
| |
Call Number |
PLASMANT @ plasmant @ |
Serial |
9117 |
| Permanent link to this record |
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Author |
Chakraborty, J.; Chatterjee, A.; Molkens, K.; Nath, I.; Arenas Esteban, D.; Bourda, L.; Watson, G.; Liu, C.; Van Thourhout, D.; Bals, S.; Geiregat, P.; Van der Voort, P. |
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Title |
Decoding Excimer Formation in Covalent–Organic Frameworks Induced by Morphology and Ring Torsion |
Type |
A1 Journal Article |
| |
Year |
2024 |
Publication |
Advanced Materials |
Abbreviated Journal |
Advanced Materials |
| |
Volume |
|
Issue |
|
Pages |
|
| |
Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
| |
Abstract |
A thorough and quantitative understanding of the fate of excitons in covalent–organic frameworks (COFs) after photoexcitation is essential for their augmented optoelectronic and photocatalytic applications via precise structure tuning. The synthesis of a library of COFs having identical chemical backbone with impeded conjugation, but varied morphology and surface topography to study the effect of these physical properties on the photophysics of the materials is herein reported. The variation of crystallite size and surface topography substantified different aggregation pattern in the COFs, which leads to disparities in their photoexcitation and relaxation properties. Depending on aggregation, an inverse correlation between bulk luminescence decay time and exciton binding energy of the materials is perceived. Further transient absorption spectroscopic analysis confirms the presence of highly localized, immobile, Frenkel excitons (of diameter 0.3–0.5 nm) via an absence of annihilation at high density, most likely induced by structural torsion of the COF skeletons, which in turn preferentially relaxes via long‐lived (nanosecond to microsecond) excimer formation (in femtosecond scale) over direct emission. These insights underpin the importance of structural and topological design of COFs for their targeted use in photocatalysis. |
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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 |
001206226700001 |
Publication Date |
2024-04-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
| |
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| |
Impact Factor |
29.4 |
Times cited |
|
Open Access |
|
| |
Notes |
PVDV, JC, AC, and IN acknowledge the FWO-Vlaanderen for research grant G020521N and the research board of UGent (BOF) through a Concerted Research Action (GOA010-17). JC acknowledges UGent for BOF postdoctoral grant (2022.0032.01). AC acknowledges FWO- Vlaanderen for postdoctoral grant (12T7521N). KM, DVT and PG acknowledges FWO- Vlaanderen for research grant G0B2921N. SB and DAE acknowledge financial support from ERC Consolidator Grant Number 815128 REALNANO. CHL acknowledges China Scholarship Council doctoral grant (201908110280). PVDV acknowledges Hercules Project AUGE/17/07 for the UV VIS DRS spectrometer and UGent BASBOF BOF20/BAS/015 for the powder X-Ray Diffractometer. PG thanks UGent for support of the Core Facility NOLIMITS. |
Approved |
Most recent IF: 29.4; 2024 IF: 19.791 |
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Call Number |
EMAT @ emat @c:irua:205967 |
Serial |
9118 |
| Permanent link to this record |
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Author |
Esteban, D.A.; Chamocho, E.G.; Carretero González, J.; Urones Garrote, E.; Otero Díaz, L.C.; Brande, D.Á. |
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Title |
Enhancing Electrochemical Properties of Walnut Shell Activated Carbon with Embedded MnO Clusters for Supercapacitor Applications |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Batteries & Supercaps |
Abbreviated Journal |
Batteries & Supercaps |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Activated carbon (AC) materials from renewable sources are widely used in electrochemical applications due to their well‐known high surface area. However, their application as electrode material in double‐layer electrochemical devices may be limited due to their relatively low electrical conductivity and lightweight. To overcome these limitations, the incorporation of pseudocapacitance metal oxide nanoparticles is an optimum approach. These nanoparticles can provide a second energy storage mechanism to the composite, mitigating the loss of surface area associated with their incorporation. As a result, the composite material is endowed with increased conductivity and higher density, making it more suitable for practical implementation in real devices. In this study, we have incorporated a fine dispersion of 1 % of MnO clusters into a highly porous activated carbon synthesized from walnut shells (WAC). The high‐resolution electron microscopy studies, combined with their related analytical techniques, allow us to determine the presence of the cluster within the matrix carbon precisely. The resulting MnO@WAC composite demonstrated significantly improved capacitive behavior compared with the WAC material, with increased volumetric capacitance and higher charge retention at higher current densities. The composite‘s electrochemical performance suggests its potential as a promising electrode material for supercapacitors, addressing drawbacks associated with traditional AC materials. |
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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 |
001198179300001 |
Publication Date |
2024-04-08 |
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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 |
2566-6223 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access |
|
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Notes |
Grants PID2020-112848RB-C21 funded by MCIN/AEI/ 10.13039/501100011033 and by the European Union PRTR funding through projects are acknowledged. Access to the ICTS- CNME for TEM is also acknowledged. |
Approved |
Most recent IF: NA |
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Call Number |
EMAT @ emat @c:irua:205463 |
Serial |
9119 |
| Permanent link to this record |
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Author |
Ignatova, K.; Vlasov, E.; Seddon, S.D.; Gauquelin, N.; Verbeeck, J.; Wermeille, D.; Bals, S.; Hase, T.P.A.; Arnalds, U.B. |
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Title |
Phase coexistence induced surface roughness in V2O3/Ni magnetic heterostructures |
Type |
A1 Journal Article |
| |
Year |
2024 |
Publication |
APL Materials |
Abbreviated Journal |
|
| |
Volume |
12 |
Issue |
4 |
Pages |
|
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
We present an investigation of the microstructure changes in V2O3 as it goes through its inherent structural phase transition. Using V2O3 films with a well-defined crystal structure deposited by reactive magnetron sputtering on r-plane Al2O3 substrates, we study the phase coexistence region and its impact on the surface roughness of the films and the magnetic properties of overlying Ni magnetic layers in V2O3/Ni hybrid magnetic heterostructures. The simultaneous presence of two phases in V2O3 during its structural phase transition was identified with high resolution x-ray diffraction and led to an increase in surface roughness observed using x-ray reflectivity. The roughness reaches its maximum at the midpoint of the transition. In V2O3/Ni hybrid heterostructures, we find a concomitant increase in the coercivity of the magnetic layer correlated with the increased roughness of the V2O3 surface. The chemical homogeneity of the V2O3 is confirmed through transmission electron microscopy analysis. High-angle annular dark field imaging and electron energy loss spectroscopy reveal an atomically flat interface between Al2O3 and V2O3, as well as a sharp interface between V2O3 and Ni. |
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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 |
001202661800003 |
Publication Date |
2024-04-01 |
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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 |
2166-532X |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
6.1 |
Times cited |
|
Open Access |
|
| |
Notes |
This work was supported by the funding from the University of Iceland Research Fund, the Icelandic Research Fund Grant No. 207111. Instrumentation funding from the Icelandic Infrastructure Fund is acknowledged. This work was based on experiments per- formed at the BM28 (XMaS) beamline at the European Synchrotron Radiation Facility, Grenoble, France. XMaS is a National Research Facility funded by the UK EPSRC and managed by the Universi- ties of Liverpool and Warwick. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717—ESTEEM3. |
Approved |
Most recent IF: 6.1; 2024 IF: 4.335 |
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Call Number |
EMAT @ emat @c:irua:205569 |
Serial |
9120 |
| Permanent link to this record |
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Author |
Vlasov, E.; Heyvaert, W.; Ni, B.; Van Gordon, K.; Girod, R.; Verbeeck, J.; Liz-Marzán, L.M.; Bals, S. |
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Title |
High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
ACS Nano |
Abbreviated Journal |
ACS Nano |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods. However, the technique is time-consuming and consequently lacks statistical value. To address this issue, we introduce herein a high-throughput methodology that combines images acquired by secondary electron-based electron beam-induced current (SEEBIC) with quantitative image analysis. As a result, the geometric chirality of hundreds of nanoparticles can be quantified in less than 1 h. When combining the drastic gain in data collection efficiency of SEEBIC with a limited number of ET data sets, a better understanding of how the chiral structure of individual chiral nanoparticles translates into the ensemble chiroptical response can be reached. |
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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 |
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Publication Date |
2024-04-26 |
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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 |
1936-0851 |
ISBN |
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Additional Links |
|
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Impact Factor |
17.1 |
Times cited |
|
Open Access |
|
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Notes |
The authors acknowledge financial support by the European Research Council (ERC CoG No. 815128 REALNANO to S.B.) and from MCIN/AEI/10.13039/501100011033 (Grant PID2020-117779RB-I00 to L.M.L.-M and FPI Fellowship PRE2021-097588 to K.V.G.). Funded by the European Union under Project 101131111 − DELIGHT, JV acknowledges the eBEAM project supported by the European Union’s Horizon 2020 research and innovation program FETPROACT-EIC-07- 2020: emerging paradigms and communities. |
Approved |
Most recent IF: 17.1; 2024 IF: 13.942 |
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Call Number |
EMAT @ emat @ |
Serial |
9121 |
| Permanent link to this record |
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Author |
Faraji, F.; Neyts, E.C.; Milošević, M.V.; Peeters, F.M. |
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Title |
Capillary Condensation of Water in Graphene Nanocapillaries |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Nano Letters |
Abbreviated Journal |
Nano Lett. |
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Volume |
24 |
Issue |
18 |
Pages |
5625-5630 |
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Keywords |
A1 Journal Article; CMT |
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Abstract |
Recent experiments have revealed that the macroscopic Kelvin equation remains surprisingly accurate even for nanoscale capillaries. This phenomenon was so far explained by the oscillatory behavior of the solid−liquid interfacial free energy. We here demonstrate thermodynamic and capillarity inconsistencies with this explanation. After revising the Kelvin equation, we ascribe its validity at nanoscale confinement to the effect of disjoining pressure.
To substantiate our hypothesis, we employed molecular dynamics simulations to evaluate interfacial heat transfer and wetting properties. Our assessments unveil a breakdown in a previously established proportionality between the work of adhesion and the Kapitza conductance at capillary heights below 1.3 nm, where the dominance of the work of adhesion shifts primarily from energy to entropy. Alternatively, the peak density of the initial water layer can effectively probe the work of adhesion. Unlike under bulk conditions, high confinement renders the work of adhesion entropically unfavorable. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Wos |
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Publication Date |
2024-05-08 |
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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 |
1530-6984 |
ISBN |
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Additional Links |
|
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Impact Factor |
10.8 |
Times cited |
|
Open Access |
|
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Notes |
This work was supported by Research Foundation-Flanders (FWO, project No. G099219N). The computational resources used in this work were provided by the HPC core facility CalcUA of the University of Antwerp, and the Flemish Supercomputer Center (VSC), funded by FWO and the Flemish Government. |
Approved |
Most recent IF: 10.8; 2024 IF: 12.712 |
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Call Number |
UA @ lucian @ |
Serial |
9123 |
| Permanent link to this record |
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Author |
Cai, Y.; Mei, D.; Chen, Y.; Bogaerts, A.; Tu, X. |
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Title |
Machine learning-driven optimization of plasma-catalytic dry reforming of methane |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Journal of Energy Chemistry |
Abbreviated Journal |
Journal of Energy Chemistry |
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Volume |
96 |
Issue |
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Pages |
153-163 |
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Keywords |
A1 Journal Article; Plasma catalysis Machine learning Process optimization Dry reforming of methane Syngas production; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
This study investigates the dry reformation of methane (DRM) over Ni/Al2O3 catalysts in a dielectric barrier discharge (DBD) non-thermal plasma reactor. A novel hybrid machine learning (ML) model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data. To address the non-linear and complex nature of the plasma-catalytic DRM process, the hybrid ML model integrates three well-established algorithms: regression trees, support vector regression, and artificial neural networks. A genetic algorithm (GA) is then used to optimize the hyperparameters of each algorithm within the hybrid ML model. The ML model achieved excellent agreement with the experimental data, demonstrating its efficacy in accurately predicting and optimizing the DRM process. The model was subsequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance. We found that the optimal discharge power (20 W), CO2/CH4 molar ratio (1.5), and Ni loading (7.8 wt%) resulted in the maximum energy yield at a total flow rate of 51 mL/min. Furthermore, we investigated the relative significance of each operating parameter on the performance of the plasmacatalytic DRM process. The results show that the total flow rate had the greatest influence on the conversion, with a significance exceeding 35% for each output, while the Ni loading had the least impact on the overall reaction performance. This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets, enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes. |
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Address |
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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 |
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Publication Date |
2024-04-25 |
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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 |
2095-4956 |
ISBN |
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Additional Links |
|
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Impact Factor |
13.1 |
Times cited |
|
Open Access |
|
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Notes |
This project received funding from the European Union’s Hori- zon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 813393. |
Approved |
Most recent IF: 13.1; 2024 IF: 2.594 |
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Call Number |
PLASMANT @ plasmant @ |
Serial |
9124 |
| Permanent link to this record |
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Author |
Albrechts, M.; Tsonev, I.; Bogaerts, A. |
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Title |
Investigation of O atom kinetics in O2plasma and its afterglow |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
Plasma Sources Science and Technology |
Abbreviated Journal |
Plasma Sources Sci. Technol. |
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Volume |
33 |
Issue |
4 |
Pages |
045017 |
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Keywords |
A1 Journal Article; oxygen plasma, pseudo-1D plug-flow kinetic model, O atoms, low-pressure validation, atmospheric pressure microwave torch; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
We have developed a comprehensive kinetic model to study the O atom kinetics in an O<sub>2</sub>plasma and its afterglow. By adopting a pseudo-1D plug-flow formalism within the kinetic model, our aim is to assess how far the O atoms travel in the plasma afterglow, evaluating its potential as a source of O atoms for post-plasma gas conversion applications. Since we could not find experimental data for pure O<sub>2</sub>plasma at atmospheric pressure, we first validated our model at low pressure (1–10 Torr) where very good experimental data are available. Good agreement between our model and experiments was achieved for the reduced electric field, gas temperature and the densities of the dominant neutral species, i.e. O<sub>2</sub>(a), O<sub>2</sub>(b) and O. Subsequently, we confirmed that the chemistry set is consistent with thermodynamic equilibrium calculations at atmospheric pressure. Finally, we investigated the O atom densities in the O<sub>2</sub>plasma and its afterglow, for which we considered a microwave O<sub>2</sub>plasma torch, operating at a pressure between 0.1 and 1 atm, for a flow rate of 20 slm and an specific energy input of 1656 kJ mol<sup>−1</sup>. Our results show that for both pressure conditions, a high dissociation degree of ca. 92% is reached within the discharge. However, the O atoms travel much further in the plasma afterglow for<italic>p</italic>= 0.1 atm (9.7 cm) than for<italic>p</italic>= 1 atm (1.4 cm), attributed to the longer lifetime (3.8 ms at 0.1 atm vs 1.8 ms at 1 atm) resulting from slower three-body recombination kinetics, as well as a higher volumetric flow rate. |
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Place of Publication |
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Language |
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Wos |
001209453500001 |
Publication Date |
2024-04-01 |
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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 |
0963-0252 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.8 |
Times cited |
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Open Access |
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Notes |
This research was supported by the Horizon Europe Framework Program ‘Research and Innovation Actions’ (RIA), Project CANMILK (Grant No. 101069491). |
Approved |
Most recent IF: 3.8; 2024 IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @c:irua:205920 |
Serial |
9125 |
| Permanent link to this record |
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Author |
Guerrero, R.M.; Lemir, I.D.; Carrasco, S.; Fernández-Ruiz, C.; Kavak, S.; Pizarro, P.; Serrano, D.P.; Bals, S.; Horcajada, P.; Pérez, Y. |
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Title |
Scaling-Up Microwave-Assisted Synthesis of Highly Defective Pd@UiO-66-NH2Catalysts for Selective Olefin Hydrogenation under Ambient Conditions |
Type |
A1 Journal Article |
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Year |
2024 |
Publication |
ACS Applied Materials & Interfaces |
Abbreviated Journal |
ACS Appl. Mater. Interfaces |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
The need to develop green and cost-effective industrial catalytic processes has led to growing interest in preparing more robust, efficient, and selective heterogeneous catalysts at a large scale. In this regard, microwave-assisted synthesis is a fast method for fabricating heterogeneous catalysts (including metal oxides, zeolites, metal–organic frameworks, and supported metal nanoparticles) with enhanced catalytic properties, enabling synthesis scale-up. Herein, the synthesis of nanosized UiO-66-NH2 was optimized via a microwave-assisted hydrothermal method to obtain defective matrices essential for the stabilization of metal nanoparticles, promoting catalytically active sites for hydrogenation reactions (760 kg·m–3·day–1 space time yield, STY). Then, this protocol was scaled up in a multimodal microwave reactor, reaching 86% yield (ca. 1 g, 1450 kg·m–3·day–1 STY) in only 30 min. Afterward, Pd nanoparticles were formed in situ decorating the nanoMOF by an effective and fast microwave-assisted hydrothermal method, resulting in the formation of Pd@UiO-66-NH2 composites. Both the localization and oxidation states of Pd nanoparticles (NPs) in the MOF were achieved using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray photoelectron spectroscopy (XPS), respectively. The optimal composite, loaded with 1.7 wt % Pd, exhibited an extraordinary catalytic activity (>95% yield, 100% selectivity) under mild conditions (1 bar H2, 25 °C, 1 h reaction time), not only in the selective hydrogenation of a variety of single alkenes (1-hexene, 1-octene, 1-tridecene, cyclohexene, and tetraphenyl ethylene) but also in the conversion of a complex mixture of alkenes (i.e., 1-hexene, 1-tridecene, and anethole). The results showed a powerful interaction and synergy between the active phase (Pd NPs) and the catalytic porous scaffold (UiO-66-NH2), which are essential for the selectivity and recyclability. |
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Wos |
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Publication Date |
2024-04-26 |
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1944-8244 |
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Impact Factor |
9.5 |
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Notes |
The authors gratefully acknowledge financial support from “Comunidad de Madrid” and European Regional Development Fund-FEDER through the project HUB MADRID+CIRCULAR; the State Research Agency (MCIN/AEI /10.13039/501100011033) through the grant with reference number CEX2019-000931-M received in the 2019 call for “Severo Ochoa Centres of Excellence” and “María de Maeztu Units of Excellence” of the State Programme for Knowledge Generation and Scientific and Technological Strengthening of the R&D&I System; and MICIU through the project “NAPOLION” (PID2022-139956OB-I00). S.K. acknowledges the Flemish Fund for Scientific Research (FWO Vlaanderen) through a PhD research grant (1181124N). |
Approved |
Most recent IF: 9.5; 2024 IF: 7.504 |
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Call Number |
EMAT @ emat @ |
Serial |
9126 |
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Author |
Leinders, G.; Grendal, O.G.; Arts, I.; Bes, R.; Prozheev, I.; Orlat, S.; Fitch, A.; Kvashnina, K.; Verwerft, M. |
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Title |
Refinement of the uranium dispersion corrections from anomalous diffraction |
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A1 Journal Article |
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Year |
2024 |
Publication |
Journal of Applied Crystallography |
Abbreviated Journal |
J Appl Cryst |
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Volume |
57 |
Issue |
2 |
Pages |
284-295 |
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Keywords |
A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; |
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Abstract |
The evolution of the uranium chemical state in uranium compounds, principally in the oxides, is of concern in the context of nuclear fuel degradation under storage and repository conditions, and in accident scenarios. The U–O system shows complicated phase relations between single-valence uranium dioxide (UO<sub>2</sub>) and different mixed-valence compounds (<italic>e.g.</italic>U<sub>4</sub>O<sub>9</sub>, U<sub>3</sub>O<sub>7</sub>and U<sub>3</sub>O<sub>8</sub>). To try resolving the electronic structure associated with unique atomic positions, a combined application of diffraction and spectroscopic techniques, such as diffraction anomalous fine structure (DAFS), can be considered. Reported here is the application of two newly developed routines for assessing a DAFS data set, with the aim of refining the uranium X-ray dispersion corrections. High-resolution anomalous diffraction data were acquired from polycrystalline powder samples of UO<sub>2</sub>(containing tetravalent uranium) and potassium uranate (KUO<sub>3</sub>, containing pentavalent uranium) using synchrotron radiation in the vicinity of the U<italic>L</italic><sub>3</sub>edge (17.17 keV). Both routines are based on an iterative refinement of the dispersion corrections, but they differ in either using the intensity of a selection of reflections or doing a full-pattern (Rietveld method) refinement. The uranium dispersion corrections obtained using either method are in excellent agreement with each other, and they show in great detail the chemical shifts and differences in fine structure expected for tetravalent and pentavalent uranium. This approach may open new possibilities for the assessment of other, more complicated, materials such as mixed-valence compounds. Additionally, the DAFS methodology can offer a significant resource optimization because each data set contains both structural (diffraction) and chemical (spectroscopy) information, which can avoid the requirement to use multiple experimental stations at synchrotron sources. |
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001208800100008 |
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2024-04-01 |
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ISSN |
1600-5767 |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
6.1 |
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Notes |
FPS Economy, SF-CORMOD; |
Approved |
Most recent IF: 6.1; 2024 IF: 2.495 |
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Call Number |
EMAT @ emat @c:irua:206011 |
Serial |
9127 |
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