Home | << 1 2 3 >> |
![]() |
Records | |||||
---|---|---|---|---|---|
Author | Gkanatsiou, A.; Lioutas, C.B.; Frangis, N.; Polychroniadis, E.K.; Prystawko, P.; Leszczynski, M.; Altantzis, T.; Van Tendeloo, G. | ||||
Title | Influence of 4H-SiC substrate miscut on the epitaxy and microstructure of AlGaN/GaN heterostructures | Type | A1 Journal article | ||
Year | 2019 | Publication | Materials science in semiconductor processing | Abbreviated Journal | Mat Sci Semicon Proc |
Volume | 91 | Issue | Pages | 159-166 | |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | AlGaN/GaN heterostructures were grown on “on-axis” and 2° off (0001) 4H-SiC substrates by metalorganic vapor phase epitaxy (MOVPE). Structural characterization was performed by transmission electron microscopy. The dislocation density, being greater in the on-axis case, is gradually reduced in the GaN layer and is forming dislocation loops in the lower region. Steps aligned along [11̅00] in the off-axis case give rise to simultaneous defect formation. In the on-axis case, an almost zero density of steps is observed, with the main origin of defects probably being the orientation mismatch at the grain boundaries between the small not fully coalesced AlN grains. V-shaped formations are observed in the AlN nucleation layer, but are more frequent in the off-axis case, probably enhanced by the presence of steps. These V-shaped formations are completely overgrown by the GaN layer, during the subsequent deposition, presenting AlGaN areas in the walls of the defect, indicating an interdiffusion between the layers. Finally, at the AlGaN/GaN heterostructure surface in the on-axis case, V-shapes are observed, with the AlN spacer and AlGaN (21% Al) thickness on relaxed GaN exceeding the critical thickness for relaxation. On the other hand, no relaxation in the form of V-shape creation is observed in the off-axis case, probably due to the smaller AlGaN thickness (less than 21% Al). The AlN spacer layer, grown in between the heterostructure, presents a uniform thickness and clear interfaces. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000454537700022 | Publication Date | 2018-11-26 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1369-8001 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.359 | Times cited | 1 | Open Access | Not_Open_Access |
Notes | Funding: This work was supported by the IKY Fellowships of Excellence for Postgraduate Studies in Greece-SIEMENS Program; the Greek General Secretariat for Research and Technology, contract SAE 013/8–2009SE 01380012; and the JU ENIAC Project LAST POWER Large Area silicon carbide Substrates and heteroepitaxial GaN for POWER device applications [grant number 120218]. Also part of the research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative–I3). T.A. acknowledges financial support from the Research Foundation Flanders (FWO, Belgium) through a post-doctoral grant. | Approved | Most recent IF: 2.359 | ||
Call Number | EMAT @ emat @UA @ admin @ c:irua:156200 | Serial | 5149 | ||
Permanent link to this record | |||||
Author | Barreca, D.; Gri, F.; Gasparotto, A.; Carraro, G.; Bigiani, L.; Altantzis, T.; Žener, B.; Lavrenčič Štangar, U.; Alessi, B.; Padmanaban, D.B.; Mariotti, D.; Maccato, C. | ||||
Title | Multi-functional MnO2nanomaterials for photo-activated applications by a plasma-assisted fabrication route | Type | A1 Journal article | ||
Year | 2019 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 11 | Issue | 1 | Pages | 98-108 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) | ||||
Abstract | Supported MnO2-based nanomaterials were fabricated on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition (PE-CVD) between 100 °C and 400 °C, starting from a fluorinated Mn(II) diamine diketonate precursor. Growth experiments yielded -MnO2 nanosystems with hierarchical morphology tuneable from dendritic structures to quasi-1D nanosystems as a function of growth temperature, whose variation enabled also a concomitant tailoring of the system fluorine content, and of the optical absorption and band gap. Preliminary photocatalytic tests were aimed at the investigation of photoinduced hydrophilic (PH) and solid phase photocatalytic (PC) performances of the present nanomaterials, as well as at the photodegradation of Plasmocorinth B azo-dye aqueous solutions. The obtained findings highlighted an attractive system photoactivity even under visible light, finely tailored by fluorine content, morphological organization and optical properties of the prepared nanostructures. The results indicate that the synthesized MnO2 nanosystems have potential applications as advanced smart materials for anti-fogging/self-cleaning end uses and water purification. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000454327500037 | Publication Date | 2018-10-10 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 7 | Open Access | OpenAccess |
Notes | Padova University DOR 2016–2017, P-DiSC #03BIRD2016-UNIPD projects, HERALD Cost Action MP1402 – 37831 and ACTION post-doc fellowship are acknowledged for financial support. T.A. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO). Thanks are also due to Prof. Sara Bals (EMAT, University of Antwerp, Belgium), Prof. Romana Cerc Korošec and to Dr. Lev Matoh (University of Ljubljana, Slovenia), and to Prof. Elza Bontempi (Brescia University, Italy). The work was also supported by EPSRC (award EP/R008841/1, EP/M024938/1). | Approved | Most recent IF: 7.367 | ||
Call Number | EMAT @ emat @UA @ admin @ c:irua:156388 | Serial | 5148 | ||
Permanent link to this record | |||||
Author | Barreca, D.; Gri, F.; Gasparotto, A.; Altantzis, T.; Gombac, V.; Fornasiero, P.; Maccato, C. | ||||
Title | Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2Nanomaterials | Type | A1 Journal Article | ||
Year | 2018 | Publication | Inorganic Chemistry | Abbreviated Journal | Inorg Chem |
Volume | 57 | Issue | 23 | Pages | 14564-14573 |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | Among transition metal oxides, MnO2 is of considerable importance for various technological end-uses,from heterogeneous catalysis to gas sensing, owing to its structural flexibility and unique properties at the nanoscale. In this work, we demonstrate the successful fabrication of supported MnO2 nanomaterials by a catalyst-free, plasmaassisted process starting from a fluorinated manganese(II) molecular source in Ar/O2 plasmas. A thorough multitechnique characterization aimed at the systematic investigation of material structure, chemical composition, and morphology revealed the formation of F-doped, oxygendeficient, MnO2-based nanomaterials, with a fluorine content tunable as a function of growth temperature (TG). Whereas phase-pure β-MnO2 was obtained for 100 °C ≤ TG ≤ 300 °C, the formation of mixed phase MnO2 + Mn2O3 nanosystems took place at 400 °C. In addition, the system nano-organization could be finely tailored, resulting in a controllable evolution from wheat-ear columnar arrays to high aspect ratio pointed-tip nanorod assemblies. Concomitantly, magnetic force microscopy analyses suggested the formation of spin domains with features dependent on material morphology. Preliminary tests in Vislight activated photocatalytic degradation of rhodamine B aqueous solutions pave the way to possible applications of the target materials in wastewater purification. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000452344400016 | Publication Date | 2018-12-03 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0020-1669 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.857 | Times cited | Open Access | Not_Open_Access | |
Notes | The present work was financially supported by Padova University DOR 2016−2018 and P-DiSC #03BIRD2016- UNIPD projects. T.A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO). Thanks are also due to Prof. Sara Bals (EMAT, University of Antwerp, Belgium) and to Dr. Giorgio Carraro (Department of Chemical Sciences, Padova University, Italy) for valuable support and experimental assistance. | Approved | Most recent IF: 4.857 | ||
Call Number | EMAT @ emat @c:irua:156245 | Serial | 5147 | ||
Permanent link to this record | |||||
Author | Guzzinati, G.; Altantzis, T.; Batuk, M.; De Backer, A.; Lumbeeck, G.; Samaee, V.; Batuk, D.; Idrissi, H.; Hadermann, J.; Van Aert, S.; Schryvers, D.; Verbeeck, J.; Bals, S. | ||||
Title | Recent Advances in Transmission Electron Microscopy for Materials Science at the EMAT Lab of the University of Antwerp | Type | A1 Journal article | ||
Year | 2018 | Publication | Materials | Abbreviated Journal | Materials |
Volume | 11 | Issue | 11 | Pages | 1304 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000444112800041 | Publication Date | 2018-07-28 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1996-1944 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 2.654 | Times cited | 15 | Open Access | OpenAccess |
Notes | Fonds Wetenschappelijk Onderzoek, G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N AUHA13009 ; European Research Council, COLOURATOM 335078 ; Universiteit Antwerpen, GOA Solarpaint ; G. Guzzinati, T. Altantzis and A. De Backer have been supported by postdoctoral fellowship grants from the Research Foundation Flanders (FWO). Funding was also received from the European Research Council (starting grant no. COLOURATOM 335078), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 770887), the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0502.18N, G.0267.18N, G.0120.12N, G.0365.15N, G.0934.17N, S.0100.18N, G.0401.16N) and from the University of Antwerp through GOA project Solarpaint. Funding for the TopSPIN precession system under grant AUHA13009, as well as for the Qu-Ant-EM microscope, is acknowledged from the HERCULES Foundation. H. Idrissi is mandated by the Belgian National Fund for Scientific Research (F.R.S.-FNRS). (ROMEO:green; preprint:; postprint:can ; pdfversion:can); saraecas; ECAS_Sara; | Approved | Most recent IF: 2.654 | ||
Call Number | EMAT @ emat @c:irua:153737UA @ admin @ c:irua:153737 | Serial | 5064 | ||
Permanent link to this record | |||||
Author | Serrano-Sevillano, J.; Reynaud, M.; Saracibar, A.; Altantzis, T.; Bals, S.; van Tendeloo, G.; Casas-Cabanas, M. | ||||
Title | Enhanced electrochemical performance of Li-rich cathode materials through microstructural control | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical chemistry, chemical physics | Abbreviated Journal | Phys Chem Chem Phys |
Volume | 20 | Issue | 20 | Pages | 23112-23122 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | The microstructural complexity of Li-rich cathode materials has so far hampered understanding the critical link between size, morphology and structural defects with both capacity and voltage fadings that this family of materials exhibits. Li2MnO3 is used here as a model material to extract reliable structure–property relationships that can be further exploited for the development of high-performing and long-lasting Li-rich oxides. A series of samples with microstructural variability have been prepared and thoroughly characterized using the FAULTS software, which allows quantification of planar defects and extraction of average crystallite sizes. Together with transmission electron microscopy (TEM) and density functional theory (DFT) results, the successful application of FAULTS analysis to Li2MnO3 has allowed rationalizing the synthesis conditions and identifying the individual impact of concurrent microstructural features on both voltage and capacity fadings, a necessary step for the development of high-capacity Li-ion cathode materials with enhanced cycle life. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000445220500071 | Publication Date | 2018-08-24 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1463-9076 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.123 | Times cited | 36 | Open Access | OpenAccess |
Notes | This work was supported by the Spanish Ministerio de la Economı´a y de la Competitividad through the project IONSTORE (MINECO ref. ENE2016-81020-R). The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). JSS and AS are grateful for computing time provided by the Spanish i2Basque Centers. MR acknowledges the Spanish State for its financial support through her post-doctoral grant Juan de la Cierva – Formacio´n (MINECO ref. FJCI-2014-19990) and her international mobility grant Jose´ Castillejos (MECD ref. CAS15/00354). S. B. acknowledges funding from the European Research Council (ERC starting grant #335078 Colouratom) and T. A. a postdoctoral grant from the Research Foundation Flanders (FWO). (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); ecas_sara | Approved | Most recent IF: 4.123 | ||
Call Number | EMAT @ emat @c:irua:154782UA @ admin @ c:irua:154782 | Serial | 5062 | ||
Permanent link to this record | |||||
Author | Gasparotto, A.; Maccato, C.; Carraro, G.; Sada, C.; Štangar, U.L.; Alessi, B.; Rocks, C.; Mariotti, D.; La Porta, A.; Altantzis, T.; Barreca, D. | ||||
Title | Surface Functionalization of Grown-on-Tip ZnO Nanopyramids: From Fabrication to Light-Triggered Applications | Type | A1 Journal Article | ||
Year | 2019 | Publication | Acs Applied Materials & Interfaces | Abbreviated Journal | Acs Appl Mater Inter |
Volume | 11 | Issue | 17 | Pages | 15881-15890 |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | We report on a combined chemical vapor deposition (CVD)/radio frequency (RF) sputtering synthetic strategy for the controlled surface modification of ZnO nanostructures by Ti-containing species. Specifically, the proposed approach consists in the CVD of grown-on-tip ZnO nanopyramids, followed by titanium RF sputtering under mild conditions. The results obtained by a thorough characterization demonstrate the successful ZnO surface functionalization with dispersed Ti-containing species in low amounts. This phenomenon, in turn, yields a remarkable enhancement of photoactivated superhydrophilic behavior, self-cleaning ability, and photocatalytic performances in comparison to bare ZnO. The reasons accounting for such an improvement are unravelled by a multitechnique analysis, elucidating the interplay between material chemico-physical properties and the corresponding functional behavior. Overall, the proposed strategy stands as an amenable tool for the mastering of semiconductor-based functional nanoarchitectures through ad hoc engineering of the system surface. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000466988800078 | Publication Date | 2019-04-18 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1944-8244 | ISBN | Additional Links | ||
Impact Factor | 7.504 | Times cited | 1 | Open Access | Not_Open_Access |
Notes | The research leading to these results has received financial support from Padova University ACTION postdoc fellowship, DOR 2016-2018, P-DiSC #03BIRD2016-UNIPD projects, and HERALD COST Action MP1402-37831. The support from EPSRC (awards EP/R008841/1 and EP/M024938/1) as well as from the Slovenian Research Agency (research core funding No. P1-0134) is also recognized. T.A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO, Belgium). The authors are grateful to Dr. Sebastiano Pianta (Department of Chemical Sciences, Padova University, Italy) for experimental assistance. | Approved | Most recent IF: 7.504 | ||
Call Number | EMAT @ emat @ | Serial | 5185 | ||
Permanent link to this record | |||||
Author | Gasparotto, A.; Maccato, C.; Sada, C.; Carraro, G.; Kondarides, D.I.; Bebelis, S.; Petala, A.; La Porta, A.; Altantzis, T.; Barreca, D. | ||||
Title | Controlled Surface Modification of ZnO Nanostructures with Amorphous TiO2for Photoelectrochemical Water Splitting | Type | A1 Journal Article | ||
Year | 2019 | Publication | Advanced Sustainable Systems | Abbreviated Journal | Adv. Sustainable Syst. |
Volume | Issue | Pages | 1900046 | ||
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | The utilization of solar radiation to trigger photoelectrochemical (PEC) water splitting has gained interest for sustainable energy production. In this study, attention is focused on the development of ZnO–TiO2 nanocomposite photoanodes. The target systems are obtained by growing porous arrays of highly crystalline, elongated ZnO nanostructures on indium tin oxide (ITO) by chemical vapor deposition. Subsequently, the obtained nanodeposits are functionalized with TiO2 via radio frequency-sputtering for different process durations, and subjected to final annealing in air. Characterization results demonstrate the successful formation of high purity composite systems in which the surface of ZnO nanostructures is decorated by ultra-small amounts of amorphous titania, whose content can be conveniently tailored as a function of deposition time. Photocurrent density measurements in sunlight triggered water splitting highlight a remarkable performance enhancement with respect to single-phase zinc and titanium oxides, with up to a threefold photocurrent increase compared to bare ZnO. These results, mainly traced back to the formation of ZnO/TiO2 heterojunctions yielding an improved photocarrier separation, show that the target nanocomposites are attractive photoanodes for efficient PEC water splitting. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | Publication Date | 2019-06-03 | ||
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2366-7486 | ISBN | Additional Links | ||
Impact Factor | Times cited | Open Access | Not_Open_Access | ||
Notes | This work was financially supported by Padova University DOR 2016–2019, P-DiSC #03BIRD2016-UNIPD, and #03BIRD2018-UNIPD projects and ACTION post-doc fellowship. A.G. acknowledges AMGAFoundation and INSTM Consortium. T.A. acknowledges a postdoctoral grant from the Research Foundation Flanders (FWO, Belgium). Thanks are also due to Dr. Sebastiano Pianta (Department of Chemical Sciences, Padova University, Italy) for experimental assistance. | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @ | Serial | 5186 | ||
Permanent link to this record | |||||
Author | Ramachandran, R.K.; Filez, M.; Solano, E.; Poelman, H.; Minjauw, M.M.; Van Daele, M.; Feng, J.-Y.; La Porta, A.; Altantzis, T.; Fonda, E.; Coati, A.; Garreau, Y.; Bals, S.; Marin, G.B.; Detavernier, C.; Dendooven, J. | ||||
Title | Chemical and Structural Configuration of Pt Doped Metal Oxide Thin Films Prepared by Atomic Layer Deposition | Type | A1 Journal article | ||
Year | 2019 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 31 | Issue | 31 | Pages | 9673-9683 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Pt doped semiconducting metal oxides and Pt metal clusters embedded in an oxide matrix are of interest for applications such as catalysis and gas sensing, energy storage and memory devices. Accurate tuning of the dopant level is crucial for adjusting the properties of these materials. Here, a novel atomic layer deposition (ALD) based method for doping Pt into In2O3 in specific, and metals in metal oxides in general, is demonstrated. This approach combines alternating exposures of Pt and In2O3 ALD processes in a single ‘supercycle’, followed by supercycle repetition leading to multilayered nanocomposites. The atomic level control of ALD and its conformal nature make the method suitable for accurate dopant control even on high surface area supports. Oxidation state, local structural environment and crystalline phase of the embedded Pt dopants were obtained by means of X-ray characterization methods and high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In addition, this approach allows characterization of the nucleation stages of metal ALD processes, by stacking those states multiple times in an oxide matrix. Regardless of experimental conditions, a few Pt ALD cycles leads to the formation of oxidized Pt species due to their highly dispersed nature, as proven by X-ray absorption spectroscopy (XAS). Grazing-incidence small-angle X-ray scattering (GISAXS) and highresolution scanning transmission electron microscopy, combined with energy dispersive X-ray spectroscopy (HR-STEM/EDXS) show that Pt is evenly distributed in the In2O3 metal oxide matrix without the formation of clusters. For a larger number of Pt ALD cycles, typ. > 10, the oxidation state gradually evolves towards fully metallic, and metallic Pt clusters are obtained within the In2O3 metal oxide matrix. This work reveals how tuning of the ALD supercycle approach for Pt doping allows controlled engineering of the Pt compositional and structural configuration within a metal oxide matrix. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000502418000010 | Publication Date | 2019-11-11 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 6 | Open Access | OpenAccess |
Notes | This research was supported by the Flemish Research Foundation (FWO-Vlaanderen), the Flemish Government (Long term structural funding – Methusalem funding and Medium scale research infrastructure funding-Hercules funding), the Special Research Fund BOF of Ghent University (GOA 01G01513) and the CALIPSO Trans National Access Program funded by the European Commission in supplying financing of travel costs. We are grateful to the SIXS and SAMBA-SOLEIL staff for smoothly running the beamline facilities. J.D. and R.K.R. are postdoctoral fellows of the FWO. | Approved | Most recent IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:164056 | Serial | 5380 | ||
Permanent link to this record | |||||
Author | Kirkwood, N.; De Backer, A.; Altantzis, T.; Winckelmans, N.; Longo, A.; Antolinez, F.V.; Rabouw, F.T.; De Trizio, L.; Geuchies, J.J.; Mulder, J.T.; Renaud, N.; Bals, S.; Manna, L.; Houtepen, A.J. | ||||
Title | Locating and controlling the Zn content in In(Zn)P quantum dots | Type | A1 Journal article | ||
Year | 2019 | Publication | Chemistry of materials | Abbreviated Journal | Chem Mater |
Volume | 32 | Issue | 32 | Pages | 557-565 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Zinc is routinely employed in the synthesis of InP quantum dots (QDs) to improve the photoluminescence efficiency and carrier mobility of the resulting In(Zn)P alloy nanostructures. The exact location of Zn in the final structures and the mechanism by which it enhances the optoelectronic properties of the QDs is debated. We use synchrotron X-ray absorbance spectroscopy to show that the majority of Zn in In(Zn)P QDs is located at their surface as Zn-carboxylates. However, a small amount of Zn is present inside the bulk of the QDs with the consequent contraction of their lattice, as confirmed by combining high resolution high-angle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM) with statistical parameter estimation theory. We further demonstrate that the Zn content and its incorporation into the QDs can be tuned by the ligation of commonly employed Zn carboxylate precursors: the use of highly reactive Zn-acetate leads to the formation of undesired Zn3P2 and the final nanostructures being characterized by broad optical features, whereas Zn-carboxylates with longer carbon chains lead to InP crystals with much lower zinc content and narrow optical features. These results can explain the differences between structural and optical properties of In(Zn)P samples reported across the literature, and provide a rational method to tune the amount of Zn in InP nanocrystals and to drive the incorporation of Zn either as surface Zn-carboxylate, as a substitutional dopant inside the InP crystal lattice, or even predominantly as Zn3P2. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000507721600056 | Publication Date | 2019-12-13 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0897-4756 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.466 | Times cited | 39 | Open Access | OpenAccess |
Notes | A.J.H. acknowledges support from the European Research Council Horizon 2020 ERC Grant Agreement No. 678004 (Doping on Demand). This research is supported by the Dutch Technology Foundation TTW, which is part of The Netherlands Organization for Scientific Research (NWO), and which is partly funded by Ministry of Economic Affairs. SB acknowledges funding from the European Research Council (grant 815128 REALNANO). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project funding G.0381.16N and a postdoctoral grant to A.D.B. AJH, LM and JM acknowledge support from the H2020 Collaborative Project TEQ (Grant No. 766900).; sygma | Approved | Most recent IF: 9.466 | ||
Call Number | EMAT @ emat @c:irua:165234 | Serial | 5438 | ||
Permanent link to this record | |||||
Author | Agrawal, H.; Patra, B.K.; Altantzis, T.; De Backer, A.; Garnett, E.C. | ||||
Title | Quantifying Strain and Dislocation Density at Nanocube Interfaces after Assembly and Epitaxy | Type | A1 Journal article | ||
Year | 2020 | Publication | Acs Applied Materials & Interfaces | Abbreviated Journal | Acs Appl Mater Inter |
Volume | 12 | Issue | 7 | Pages | 8788-8794 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Nanoparticle self-assembly and epitaxy are utilized extensively to make 1D and 2D structures with complex shapes. High-resolution transmission electron microscopy (HRTEM) has shown that single-crystalline interfaces can form, but little is known about the strain and dislocations at these interfaces. Such information is critically important for applications: drastically reducing dislocation density was the key breakthrough enabling widespread implementation of light-emitting diodes, while strain engineering has been fundamental to modern high-performance transistors, solar cells, and thermoelectrics. In this work, the interfacial defect and strain formation after selfassembly and room temperature epitaxy of 7 nm Pd nanocubes capped with polyvinylpyrrolidone (PVP) is examined. It is observed that, during ligand removal, the cubes move over large distances on the substrate, leading to both spontaneous self-assembly and epitaxy to form single crystals. Subsequently, atomically resolved images are used to quantify the strain and dislocation density at the epitaxial interfaces between cubes with different lateral and angular misorientations. It is shown that dislocation- and strain-free interfaces form when the nanocubes align parallel to each other. Angular misalignment between adjacent cubes does not necessarily lead to grain boundaries but does cause dislocations, with higher densities associated with larger rotations. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000515214300101 | Publication Date | 2020-02-19 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1944-8244 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 9.5 | Times cited | Open Access | OpenAccess | |
Notes | Fonds Wetenschappelijk Onderzoek; H2020 Research Infrastructures, 731019 ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 14846 ; The work at AMOLF is part of the research program of the “Nederlandse Organisatie voor Wetenschappelijk Onderzoek” (NWO). This work was supported by the NWO VIDI grant (project no. 14846). The authors would like to thank Reinout Jaarsma and Dr. Sven Askes for helping with the XPS measurements. A.D.B. acknowledges a postdoctoral grant from the research foundation Flanders (FWO). The authors acknowledge financial support from the European Commission under the Horizon 2020 Programme by means of the grant agreement no. 731019 EUSMI. | Approved | Most recent IF: 9.5; 2020 IF: 7.504 | ||
Call Number | EMAT @ emat @c:irua:167770 | Serial | 6398 | ||
Permanent link to this record | |||||
Author | Milagres de Oliveira, T.; Albrecht, W.; González-Rubio, G.; Altantzis, T.; Lobato Hoyos, I.P.; Béché, A.; Van Aert, S.; Guerrero-Martínez, A.; Liz-Marzán, L.M.; Bals, S. | ||||
Title | 3D Characterization and Plasmon Mapping of Gold Nanorods Welded by Femtosecond Laser Irradiation | Type | A1 Journal article | ||
Year | 2020 | Publication | Acs Nano | Abbreviated Journal | Acs Nano |
Volume | 14 | Issue | Pages | acsnano.0c02610 | |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Ultrafast laser irradiation can induce morphological and structural changes in plasmonic nanoparticles. Gold nanorods (Au NRs), in particular, can be welded together upon irradiation with femtosecond laser pulses, leading to dimers and trimers through the formation of necks between individual nanorods. We used electron tomography to determine the 3D (atomic) structure at such necks for representative welding geometries and to characterize the induced defects. The spatial distribution of localized surface plasmon modes for different welding configurations was assessed by electron energy loss spectroscopy. Additionally, we were able to directly compare the plasmon line width of single-crystalline and welded Au NRs with single defects at the same resonance energy, thus making a direct link between the structural and plasmonic properties. In this manner, we show that the occurrence of (single) defects results in significant plasmon broadening. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000586793400016 | Publication Date | 2020-08-19 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1936-0851 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 17.1 | Times cited | 25 | Open Access | OpenAccess |
Notes | This project has received funding from the European Research Council under the European Union's Horizon 2020 research and innovation program (ERC Consolidator Grants #815128 – REALNANO and #770887 – PICOMETRICS). The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project funding G.0381.16N and G.0267.18N. W.A. acknowledges an Individual Fellowship funded by the Marie 27 Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 797153, SOPMEN). G.G.-R. acknowledge receipt of FPI Fellowship from the Spanish MINECO. This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grants RTI2018-095844-B-I00 and MAT2017-86659-R) and the Madrid Regional Government (Grant P2018/NMT-4389). A.B. acknowledges funding from FWO project G093417N and from the European Union's Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. L.M.L.-M. acknowledges the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency (Grant No. MDM-2017-0720); Comunidad de Madrid, P2018/NMT-4389 ; Ministerio de Ciencia, Innovación y Universidades, MAT2017-86659-R RTI2018-095844-B-I00 ; Ministerio de Economía y Competitividad; H2020 Marie Sklodowska-Curie Actions, 797153 ; Fonds Wetenschappelijk Onderzoek, G.0267.18N G.0381.16N G093417N ; H2020 Research Infrastructures, 823717 ; H2020 European Research Council, 770887 815128 ; Agencia Estatal de Investigación, Ministerio de Ciencia, Innovación y Universidades, MDM-2017-0720 ; sygma | Approved | Most recent IF: 17.1; 2020 IF: 13.942 | ||
Call Number | EMAT @ emat @c:irua:172440 | Serial | 6426 | ||
Permanent link to this record | |||||
Author | Wang, D.; Dasgupta, T.; van der Wee, E.B.; Zanaga, D.; Altantzis, T.; Wu, Y.; Coli, G.M.; Murray, C.B.; Bals, S.; Dijkstra, M.; van Blaaderen, A. | ||||
Title | Binary icosahedral clusters of hard spheres in spherical confinement | Type | A1 Journal article | ||
Year | 2020 | Publication | Nature Physics | Abbreviated Journal | Nat Phys |
Volume | Issue | Pages | 1-9 | ||
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | The influence of geometry on the local and global packing of particles is important to many fundamental and applied research themes, such as the structure and stability of liquids, crystals and glasses. Here we show by experiments and simulations that a binary mixture of hard-sphere-like nanoparticles crystallizing into a MgZn(2)Laves phase in bulk spontaneously forms icosahedral clusters in slowly drying droplets. Using advanced electron tomography, we are able to obtain the real-space coordinates of all the spheres in the icosahedral clusters of up to about 10,000 particles. The local structure of 70-80% of the particles became similar to that of the MgCu(2)Laves phase. These observations are important for photonic applications. In addition, we observed in simulations that the icosahedral clusters nucleated away from the spherical boundary, which is distinctly different from that of the single species clusters. Our findings open the way for particle-level studies of nucleation and growth of icosahedral clusters, and of binary crystallization. The authors investigate out-of-equilibrium crystallization of a binary mixture of sphere-like nanoparticles in small droplets. They observe the spontaneous formation of an icosahedral structure with stable MgCu(2)phases, which are promising for photonic applications. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000564497300002 | Publication Date | 2020-08-31 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1745-2473; 1745-2481 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 19.6 | Times cited | 38 | Open Access | OpenAccess |
Notes | ; D.W., E.B.v.d.W. and A.v.B. acknowledge partial financial support from the European Research Council under the European Union's Seventh Framework Programme (FP-2007-2013)/ERC Advanced Grant Agreement 291667 HierarSACol. T.D. and M. D. acknowledge financial support from the Industrial Partnership Programme, 'Computational Sciences for Energy Research' (grant number 13CSER025), of the Netherlands Organization for Scientific Research (NWO), which was co-financed by Shell Global Solutions International BV G.M.C. was also financially supported by NWO. S.B. acknowledges financial support from ERC Consolidator Grant Number 815128 REALNANO. T.A. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). C.B.M. and Y.W. acknowledge support for materials synthesis from the Office of Naval Research Multidisciplinary University Research Initiative Award ONR N00014-18-1-2497. G. A. Blab is gratefully acknowledged for 3D printing numerous truncated tetrahedra, which increased our understanding of the connection between the binary icosahedral cluster and Laves phase structures. N. Tasios is sincerely thanked for providing the code for the diffraction pattern calculation. M. Hermes is sincerely thanked for providing interactive views of the structures in this work. We thank G. van Tendeloo, M. Engel, J. Wang, S. Dussi, L. Filion, E. Boattini, S. Paliwal, N. Tasios, B. van der Meer, I. Lobato, J. Wu and L. Laurens for fruitful discussions. We acknowledge the EM Square centre at Utrecht University for the access to the microscopes. ; sygma | Approved | Most recent IF: 19.6; 2020 IF: 22.806 | ||
Call Number | UA @ admin @ c:irua:172044 | Serial | 6460 | ||
Permanent link to this record | |||||
Author | Bagiński, M.; Pedrazo-Tardajos, A.; Altantzis, T.; Tupikowska, M.; Vetter, A.; Tomczyk, E.; Suryadharma, R.N.S.; Pawlak, M.; Andruszkiewicz, A.; Górecka, E.; Pociecha, D.; Rockstuhl, C.; Bals, S.; Lewandowski, W. | ||||
Title | Understanding and Controlling the Crystallization Process in Reconfigurable Plasmonic Superlattices | Type | A1 Journal article | ||
Year | 2021 | Publication | Acs Nano | Abbreviated Journal | Acs Nano |
Volume | Issue | Pages | acsnano.0c09746 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | The crystallization of nanomaterials is a primary source of solid-state, photonic structures. Thus, a detailed understanding of this process is of paramount importance for the successful application of photonic nanomaterials in emerging optoelectronic technologies. While colloidal crystallization has been thoroughly studied, for example, with advanced in situ electron microscopy methods, the noncolloidal crystallization (freezing) of nanoparticles (NPs) remains so far unexplored. To fill this gap, in this work, we present proof-of principle experiments decoding a crystallization of reconfigurable assemblies of NPs at a solid state. The chosen material corresponds to an excellent testing bed, as it enables both in situ and ex situ investigation using X-ray diffraction (XRD), transmission electron microscopy (TEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), atomic force microscopy (AFM), and optical spectroscopy in visible and ultraviolet range (UV−vis) techniques. In particular, ensemble measurements with small-angle XRD highlighted the dependence of the correlation length in the NPs assemblies on the number of heating/cooling cycles and the rate of cooling. Ex situ TEM imaging further supported these results by revealing a dependence of domain size and structure on the sample preparation route and by showing we can control the domain size over 2 orders of magnitude. The application of HAADF-STEM tomography, combined with in situ thermal control, provided three-dimensional single-particle level information on the positional order evolution within assemblies. This combination of real and reciprocal space provides insightful information on the anisotropic, reversibly reconfigurable assemblies of NPs. TEM measurements also highlighted the importance of interfaces in the polydomain structure of nanoparticle solids, allowing us to understand experimentally observed differences in UV−vis extinction spectra of the differently prepared crystallites. Overall, the obtained results show that the combination of in situ heating HAADF-STEM tomography with XRD and ex situ TEM techniques is a powerful approach to study nanoparticle freezing processes and to reveal the crucial impact of disorder in the solid-state aggregates of NPs on their plasmonic properties. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000634569100101 | Publication Date | 2021-02-23 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1936-0851 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 13.942 | Times cited | 10 | Open Access | OpenAccess |
Notes | Ministerstwo Nauki i Szkolnictwa Wyzszego, 0112/DIA/2019/48 ; European Commission, 731019 E171000009 (EUSMI) ; Narodowe Centrum Nauki, 2016/21/N/ST5/03356 ; Deutsche Forschungsgemeinschaft, RO 3640/12-1 ; Fundacja na rzecz Nauki Polskiej, First TEAM2016–2/15 ; European Research Council, 815128 (REALNANO) ; sygma; | Approved | Most recent IF: 13.942 | ||
Call Number | EMAT @ emat @c:irua:175872 | Serial | 6673 | ||
Permanent link to this record | |||||
Author | Wu, L.; Kolmeijer, K.E.; Zhang, Y.; An, H.; Arnouts, S.; Bals, S.; Altantzis, T.; Hofmann, J.P.; Costa Figueiredo, M.; Hensen, E.J.M.; Weckhuysen, B.M.; van der Stam, W. | ||||
Title | Stabilization effects in binary colloidal Cu and Ag nanoparticle electrodes under electrochemical CO₂ reduction conditions | Type | A1 Journal article | ||
Year | 2021 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | 13 | Issue | 9 | Pages | 4835-4844 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Nanoparticle modified electrodes constitute an attractive way to tailor-make efficient carbon dioxide (CO2) reduction catalysts. However, the restructuring and sintering processes of nanoparticles under electrochemical reaction conditions not only impedes the widespread application of nanoparticle catalysts, but also misleads the interpretation of the selectivity of the nanocatalysts. Here, we colloidally synthesized metallic copper (Cu) and silver (Ag) nanoparticles with a narrow size distribution (<10%) and utilized them in electrochemical CO2 reduction reactions. Monometallic Cu and Ag nanoparticle electrodes showed severe nanoparticle sintering already at low overpotential of -0.8 V vs. RHE, as evidenced by ex situ SEM investigations, and potential-dependent variations in product selectivity that resemble bulk Cu (14% for ethylene at -1.3 V vs. RHE) and Ag (69% for carbon monoxide at -1.0 V vs. RHE). However, by co-deposition of Cu and Ag nanoparticles, a nanoparticle stabilization effect was observed between Cu and Ag, and the sintering process was greatly suppressed at CO2 reducing potentials (-0.8 V vs. RHE). Furthermore, by varying the Cu/Ag nanoparticle ratio, the CO2 reduction reaction (CO2RR) selectivity towards methane (maximum of 20.6% for dense Cu-2.5-Ag-1 electrodes) and C-2 products (maximum of 15.7% for dense Cu-1-Ag-1 electrodes) can be tuned, which is attributed to a synergistic effect between neighbouring Ag and Cu nanoparticles. We attribute the stabilization of the nanoparticles to the positive enthalpies of Cu-Ag solid solutions, which prevents the dissolution-redeposition induced particle growth under CO2RR conditions. The observed nanoparticle stabilization effect enables the design and fabrication of active CO2 reduction nanocatalysts with high durability. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000628024200011 | Publication Date | 2021-02-22 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 7.367 | Times cited | 24 | Open Access | OpenAccess |
Notes | This work is funded by the Strategic UU-TU/e Alliance project ‘Joint Centre for Chemergy Research’ (budget holder B. M. W.). S. B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO). S. A. and T. A. acknowledge funding from the University of Antwerp Research fund (BOF). We thank Eric Hellebrand (Faculty of Geosciences, Utrecht University) for the assistance in SEM measurements. Dr Ramon Oord (ARC Chemical Building Blocks Consortium, Faculty of Science, Utrecht University) is acknowledged for assisting with the grazing incidence XRD measurements; sygma | Approved | Most recent IF: 7.367 | ||
Call Number | UA @ admin @ c:irua:176723 | Serial | 6737 | ||
Permanent link to this record | |||||
Author | Albrecht, W.; Arslan Irmak, E.; Altantzis, T.; Pedrazo‐Tardajos, A.; Skorikov, A.; Deng, T.‐S.; van der Hoeven, J.E.S.; van Blaaderen, A.; Van Aert, S.; Bals, S. | ||||
Title | 3D Atomic‐Scale Dynamics of Laser‐Light‐Induced Restructuring of Nanoparticles Unraveled by Electron Tomography | Type | A1 Journal article | ||
Year | 2021 | Publication | Advanced Materials | Abbreviated Journal | Adv Mater |
Volume | Issue | Pages | 2100972 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Understanding light–matter interactions in nanomaterials is crucial for optoelectronic, photonic, and plasmonic applications. Specifically, metal nanoparticles (NPs) strongly interact with light and can undergo shape transformations, fragmentation and ablation upon (pulsed) laser excitation. Despite being vital for technological applications, experimental insight into the underlying atomistic processes is still lacking due to the complexity of such measurements. Herein, atomic resolution electron tomography is performed on the same mesoporous-silica-coated gold nanorod, before and after femtosecond laser irradiation, to assess the missing information. Combined with molecular dynamics (MD) simulations based on the experimentally determined 3D atomic-scale morphology, the complex atomistic rearrangements, causing shape deformations and defect generation, are unraveled. These rearrangements are simultaneously driven by surface diffusion, facet restructuring, and strain formation, and are influenced by subtleties in the atomic distribution at the surface. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000671662000001 | Publication Date | 2021-07-11 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0935-9648 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 19.791 | Times cited | 8 | Open Access | OpenAccess |
Notes | W.A. and E.A.I. contributed equally to this work. The authors acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128 – REALNANO and No. 770887 – PICOMETRICS), the European Union’s Seventh Framework Programme (ERC Advanced Grant No. 291667 – HierarSACol), and the European Commission (EUSMI). W.A. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in the Horizon2020 program (Grant 797153, SOPMEN). T.-S.D. acknowledges financial support from the National Science Foundation of China (NSFC, Grant No. 61905056). The authors also acknowledge financial support by the Research Foundation Flanders (FWO Grant G.0267.18N).; sygmaSB | Approved | Most recent IF: 19.791 | ||
Call Number | EMAT @ emat @c:irua:179781 | Serial | 6805 | ||
Permanent link to this record | |||||
Author | Hudry, D.; De Backer, A.; Popescu, R.; Busko, D.; Howard, I.A.; Bals, S.; Zhang, Y.; Pedrazo‐Tardajos, A.; Van Aert, S.; Gerthsen, D.; Altantzis, T.; Richards, B.S. | ||||
Title | Interface Pattern Engineering in Core‐Shell Upconverting Nanocrystals: Shedding Light on Critical Parameters and Consequences for the Photoluminescence Properties | Type | A1 Journal article | ||
Year | 2021 | Publication | Small | Abbreviated Journal | Small |
Volume | Issue | Pages | 2104441 | ||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Advances in controlling energy migration pathways in core-shell lanthanide (Ln)-based hetero-nanocrystals (HNCs) have relied heavily on assumptions about how optically active centers are distributed within individual HNCs. In this article, it is demonstrated that different types of interface patterns can be formed depending on shell growth conditions. Such interface patterns are not only identified but also characterized with spatial resolution ranging from the nanometer- to the atomic-scale. In the most favorable cases, atomic-scale resolved maps of individual particles are obtained. It is also demonstrated that, for the same type of core-shell architecture, the interface pattern can be engineered with thicknesses of just 1 nm up to several tens of nanometers. Total alloying between the core and shell domains is also possible when using ultra-small particles as seeds. Finally, with different types of interface patterns (same architecture and chemical composition of the core and shell domains) it is possible to modify the output color (yellow, red, and green-yellow) or change (improvement or degradation) the absolute upconversion quantum yield. The results presented in this article introduce an important paradigm shift and pave the way toward the emergence of a new generation of core-shell Ln-based HNCs with better control over their atomic-scale organization. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000710758000001 | Publication Date | 2021-10-25 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1613-6810 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 8.643 | Times cited | 17 | Open Access | OpenAccess |
Notes | The authors would like to acknowledge the financial support provided by the Helmholtz Recruitment Initiative Fellowship (B.S.R.) and the Helmholtz Association's Research Field Energy (Materials and Technologies for the Energy Transition program, Topic 1 Photovoltaics and Wind Energy). The authors would like to thank the Karlsruhe Nano Micro Facility (KNMF) for STEM access. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant agreement no. 770887 PICOMETRICS to S.V.A. and Grant agreement no. 815128 REALNANO to S.B.). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Projects no. G.0502.18N, G.0267.18N, and a postdoctoral grant to A.D.B. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). This project had received funding (EUSMI proposal #E181100205) from the European Union's Horizon 2020 Research and Innovation Programme under Grant agreement no 731019 (EUSMI). D.H. would like to thank “CGFigures” for helpful tutorials on 3D graphics with Blender.; sygmaSB | Approved | Most recent IF: 8.643 | ||
Call Number | EMAT @ emat @c:irua:183285 | Serial | 6817 | ||
Permanent link to this record | |||||
Author | Coeck, R.; Meeprasert, J.; Li, G.; Altantzis, T.; Bals, S.; Pidko, E.A.; De Vos, D.E. | ||||
Title | Gold and silver-catalyzed reductive amination of aromatic carboxylic acids to benzylic amines | Type | A1 Journal article | ||
Year | 2021 | Publication | Acs Catalysis | Abbreviated Journal | Acs Catal |
Volume | 11 | Issue | 13 | Pages | 7672-7684 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | The reductive amination of benzoic acid and its derivatives would be an effective addition to current synthesis methods for benzylamine. However, with current technology it is very difficult to keep the aromaticity intact when starting from benzoic acid, and salt wastes are often generated in the process. Here, we report a heterogeneous catalytic system for such a reductive amination, requiring solely H-2 and NH3 as the reactants. The Ag/TiO2 or Au/TiO2 catalysts can be used multiple times, and very little noble metal is required, only 0.025 mol % Au. The catalysts are bifunctional: the support catalyzes the dehydration of both the ammonium carboxylate to the amide and of the amide to the nitrile, while the sites at the metal-support interface promote the hydrogenation of the in situ generated nitrile. Yields of up to 92% benzylamine were obtained. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000670659900005 | Publication Date | 2021-06-10 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2155-5435 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 10.614 | Times cited | 16 | Open Access | OpenAccess |
Notes | R.C. thanks the FWO for his SB PhD fellowship. D.E.D.V. acknowledges FWO for research project funding, as well as KU Leuven for funding in the Metusalem program Casas. S.B. acknowledges support from the European Research Council (ERC Consolidator grant #815128 REALNANO). T.A. acknowledges funding from the University of Antwerp Research fund (BOF). E.A.P. acknowledges the support from the European Research Council (ERC Consolidator grant #725686 DeliCAT). J.M. acknowledges financial support through the Royal Thai Government Scholarship. DFT calculations on SURFsara supercomputer facilities were performed with support from the Netherlands Organization for Scientific Research (NWO).; sygmaSB | Approved | Most recent IF: 10.614 | ||
Call Number | UA @ admin @ c:irua:179851 | Serial | 6840 | ||
Permanent link to this record | |||||
Author | Wang, D.; van der Wee, E.B.; Zanaga, D.; Altantzis, T.; Wu, Y.; Dasgupta, T.; Dijkstra, M.; Murray, C.B.; Bals, S.; van Blaaderen, A. | ||||
Title | Quantitative 3D real-space analysis of Laves phase supraparticles | Type | A1 Journal article | ||
Year | 2021 | Publication | Nature Communications | Abbreviated Journal | Nat Commun |
Volume | 12 | Issue | 1 | Pages | 3980 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | 3D real-space analysis of thick nanoparticle crystals is non-trivial. Here, the authors demonstrate the structural analysis of a bulk-like Laves phase by imaging an off-stoichiometric binary mixture of hard-sphere-like nanoparticles in spherical confinement by electron tomography, enabling defect analysis on the single-particle level. Assembling binary mixtures of nanoparticles into crystals, gives rise to collective properties depending on the crystal structure and the individual properties of both species. However, quantitative 3D real-space analysis of binary colloidal crystals with a thickness of more than 10 layers of particles has rarely been performed. Here we demonstrate that an excess of one species in the binary nanoparticle mixture suppresses the formation of icosahedral order in the self-assembly in droplets, allowing the study of bulk-like binary crystal structures with a spherical morphology also called supraparticles. As example of the approach, we show single-particle level analysis of over 50 layers of Laves phase binary crystals of hard-sphere-like nanoparticles using electron tomography. We observe a crystalline lattice composed of a random mixture of the Laves phases. The number ratio of the binary species in the crystal lattice matches that of a perfect Laves crystal. Our methodology can be applied to study the structure of a broad range of binary crystals, giving insights into the structure formation mechanisms and structure-property relations of nanomaterials. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000687320200032 | Publication Date | 2021-06-25 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2041-1723 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 12.124 | Times cited | 10 | Open Access | OpenAccess |
Notes | M. Hermes is sincerely thanked for providing interactive views of the structures in this work. The authors thank I. Lobato, S. Dussi, L. Filion, E. Boattini, S. Paliwal, B. van der Meer and X. Xie for fruitful discussions. D.W., E.B.v.d.W. and A.v.B. acknowledge partial financial support from the European Research Council under the European Union’s Seventh Framework Program (FP-2007-2013)/ERC Advanced Grant Agreement 291667 HierarSACol. T.D. and M.D. acknowledge financial support from the Industrial Partnership Program, “Computational Sciences for Energy Research” (Grant no. 13CSER025), of the Netherlands Organization for Scientific Research (NWO), which was co-financed by Shell Global Solutions International B.V. S.B. acknowledges financial support from ERC Consolidator Grant No. 815128 REALNANO. T.A. acknowledges a post-doctoral grant from the Research Foundation Flanders (FWO, Belgium). C.B.M and Y.W. acknowledge support for materials synthesis from the Office of Naval Research Multidisciplinary University Research Initiative Award ONR N00014-18-1-2497. The authors acknowledge EM Square center at Utrecht University for the access to the microscopes.; sygmaSB | Approved | Most recent IF: 12.124 | ||
Call Number | UA @ admin @ c:irua:181662 | Serial | 6845 | ||
Permanent link to this record | |||||
Author | Zheng, Y.-R.; Vernieres, J.; Wang, Z.; Zhang, K.; Hochfilzer, D.; Krempl, K.; Liao, T.-W.; Presel, F.; Altantzis, T.; Fatermans, J.; Scott, S.B.; Secher, N.M.; Moon, C.; Liu, P.; Bals, S.; Van Aert, S.; Cao, A.; Anand, M.; Nørskov, J.K.; Kibsgaard, J.; Chorkendorff, I. | ||||
Title | Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts | Type | A1 Journal article | ||
Year | 2021 | Publication | Nature Energy | Abbreviated Journal | Nat Energy |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Development of low-cost and high-performance oxygen evolution reaction catalysts is key to implementing polymer electrolyte membrane water electrolyzers for hydrogen production. Iridium-based oxides are the state-of-the-art acidic oxygen evolution reactio catalysts but still suffer from inadequate activity and stability, and iridium's scarcity motivates the discovery of catalysts with lower iridium loadings. Here we report a mass-selected iridium-tantalum oxide catalyst prepared by a magnetron-based cluster source with considerably reduced noble-metal loadings beyond a commercial IrO2 catalyst. A sensitive electrochemistry/mass-spectrometry instrument coupled with isotope labelling was employed to investigate the oxygen production rate under dynamic operating conditions to account for the occurrence of side reactions and quantify the number of surface active sites. Iridium-tantalum oxide nanoparticles smaller than 2 nm exhibit a mass activity of 1.2 ± 0.5 kA “g” _“Ir” ^“-1” and a turnover frequency of 2.3 ± 0.9 s-1 at 320 mV overpotential, which are two and four times higher than those of mass-selected IrO2, respectively. Density functional theory calculations reveal that special iridium coordinations and the lowered aqueous decomposition free energy might be responsible for the enhanced performance. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000728458000001 | Publication Date | 2021-12-09 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2058-7546 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 95 | Open Access | OpenAccess | |
Notes | Y.-R.Z. and Z.W acknowledge funding from the Toyota Research Institute. This project has received funding from VILLUM FONDEN (grant no. 9455) and the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grants no. 741860-CLUNATRA, no. 815128−REALNANO and no. 770887−PICOMETRICS). S.B. and S.V.A. acknowledge funding from the Research Foundation Flanders (FWO, G026718N and G050218N). T.A. acknowledges the University of Antwerp Research Fund (BOF). STEM measurements were supported by the European Union's Horizon 2020 Research Infrastructure-Integrating Activities for Advanced Communities under grant agreement No 823717 – ESTEEM3.; sygmaSB | Approved | Most recent IF: NA | ||
Call Number | EMAT @ emat @c:irua:184794 | Serial | 6903 | ||
Permanent link to this record | |||||
Author | Altantzis, T.; Wang, D.; Kadu, A.; van Blaaderen, A.; Bals, S. | ||||
Title | Optimized 3D Reconstruction of Large, Compact Assemblies of Metallic Nanoparticles | Type | A1 Journal article | ||
Year | 2021 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
Volume | 125 | Issue | 47 | Pages | 26240-26246 |
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | 3D characterization of assemblies of nanoparticles is of great importance to determine their structure-property connection. Such investigations become increasingly more challenging when the assemblies become larger and more compact. In this paper, we propose an optimized approach for electron tomography to minimize artefacts related to beam broadening in High Angle Annular Dark-Field Scanning Transmission Electron Microscopy mode. These artefacts are typically present at one side of the reconstructed 3D data set for thick nanoparticle assemblies. To overcome this problem, we propose a procedure in which two tomographic tilt series of the same sample are acquired. After acquiring the first series, the sample is flipped over 180o, and a second tilt series is acquired. By merging the two reconstructions, blurring in the reconstructed volume is minimized. Next, this approach is combined with an advanced three-dimensional reconstruction algorithm yielding quantitative structural information. Here, the approach is applied to a thick and compact assembly of spherical Au nanoparticles, but the methodology can we used to investigate a broad range of samples. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000752810100031 | Publication Date | 2021-12-02 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 4.536 | Times cited | 4 | Open Access | OpenAccess |
Notes | This work was supported by the European Research Council (grant No. 815128−REALNANO to S.B.). T.A. acknowledges the University of Antwerp Research fund (BOF). D.W. and A.v.B. acknowledge partial financial support from the European Research Council under the European Union’s Seventh Framework Program (FP-2007-2013)/ERC Advanced Grant Agreement 291667 HierarSACol. D.W. acknowledges an Individual Fellowship funded by the Marie Sklodowska-Curie Actions (MSCA) in Horizon 2020 program (grant 894254 SuprAtom).; sygmaSB | Approved | Most recent IF: 4.536 | ||
Call Number | EMAT @ emat @c:irua:185224 | Serial | 6904 | ||
Permanent link to this record | |||||
Author | Fatermans, J.; Romolini, G.; Altantzis, T.; Hofkens, J.; Roeffaers, M.B.J.; Bals, S.; Van Aert, S. | ||||
Title | Atomic-scale detection of individual lead clusters confined in Linde Type A zeolites | Type | A1 Journal article | ||
Year | 2022 | Publication | Nanoscale | Abbreviated Journal | Nanoscale |
Volume | Issue | Pages | |||
Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | Structural analysis of metal clusters confined in nanoporous materials is typically performed by X-ray-driven techniques. Although X-ray analysis has proved its strength in the characterization of metal clusters, it provides averaged structural information. Therefore, we here present an alternative workflow for bringing the characterization of confined metal clusters towards the local scale. This workflow is based on the combination of aberration-corrected transmission electron microscopy (TEM), TEM image simulations, and powder X-ray diffraction (XRD) with advanced statistical techniques. In this manner, we were able to characterize the clustering of Pb atoms in Linde Type A (LTA) zeolites with Pb loadings as low as 5 wt%. Moreover, individual Pb clusters could be directly detected. The proposed methodology thus enables a local-scale characterization of confined metal clusters in zeolites. This is important for further elucidation of the connection between the structure and the physicochemical properties of such systems. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000809619900001 | Publication Date | 0000-00-00 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2040-3364 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.7 | Times cited | 2 | Open Access | OpenAccess |
Notes | The authors acknowledge the Research Foundation Flanders through project fundings (FWO, G026718N, G050218N, ZW15_09-G0H6316N, and W002221N) and through a PhD scholarship to G.R. (grant 11C6920N), as well as iBOF-21-085 PERSIST. T.A. and S.V.A. acknowledge funding from the University of Antwerp Research fund (BOF). J.H. acknowledges the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) and the MPI as MPI fellow. M.R. acknowledges funding by the KU Leuven Research Fund (C14/19/079). S.B. and S.V.A. acknowledge funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants No. 815128−REALNANO and No. 770887−PICOMETRICS). The authors thank Dr. D. Chernyshov for the collection of XRD measurements. | Approved | Most recent IF: 6.7 | ||
Call Number | EMAT @ emat @c:irua:189061 | Serial | 7076 | ||
Permanent link to this record | |||||
Author | Parastaev, A.; Muravev, V.; Osta, E.H.; Kimpel, T.F.; Simons, J.F.M.; van Hoof, A.J.F.; Uslamin, E.; Zhang, L.; Struijs, J.J.C.; Burueva, D.B.; Pokochueva, E.V.; Kovtunov, K.V.; Koptyug, I.V.; Villar-Garcia, I.J.; Escudero, C.; Altantzis, T.; Liu, P.; Béché, A.; Bals, S.; Kosinov, N.; Hensen, E.J.M. | ||||
Title | Breaking structure sensitivity in CO2 hydrogenation by tuning metal–oxide interfaces in supported cobalt nanoparticles | Type | A1 Journal article | ||
Year | 2022 | Publication | Nature Catalysis | Abbreviated Journal | Nat Catal |
Volume | 5 | Issue | 11 | Pages | 1051-1060 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT) | ||||
Abstract | A high dispersion of the active metal phase of transition metals on oxide supports is important when designing efficient heterogeneous catalysts. Besides nanoparticles, clusters and even single metal atoms can be attractive for a wide range of reactions. However, many industrially relevant catalytic transformations suffer from structure sensitivity, where reducing the size of the metal particles below a certain size substantially lowers catalytic performance. A case in point is the low activity of small cobalt nanoparticles in the hydrogenation of CO and CO2. Here we show how engineering of catalytic sites at the metal–oxide interface in cerium oxide–zirconium dioxide (ceria–zirconia)-supported cobalt can overcome this structure sensitivity. Few-atom cobalt clusters dispersed on 3 nm cobalt(II)-oxide particles stabilized by ceria–zirconia yielded a highly active CO2 methanation catalyst with a specific activity higher than that of larger particles under the same conditions. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000884939300006 | Publication Date | 2022-11-17 | |
Series Editor ![]() |
Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2520-1158 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 37.8 | Times cited | 32 | Open Access | OpenAccess |
Notes | This research was supported by the Applied and Engineering Sciences division of the Netherlands Organization for Scientific Research through the Alliander (now Qirion) Perspective program on Plasma Conversion of CO2. We acknowledge Diamond Light Source for time on beamline B18 under proposal SP20715-1. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823717 – ESTEEM3. S.B. acknowledges support from the European Research Council (ERC Consolidator Grant #815128 REALNANO) and T.A. acknowledges funding from the University of Antwerp Research fund (BOF). A.B. received funding from the European Union under grant agreement No 823717 – ESTEEM3. The authors acknowledge funding through the Hercules grant (FWO, University of Antwerp) I003218N “Infrastructure for imaging nanoscale processes in gas/vapour or liquid environments”. I.V.K., D.B.B., and E.V.P. acknowledge the Russian Ministry of Science and Higher Education (contract 075-15-2021-580) for financial support of parahydrogen-based studies. Experiments using synchrotron radiation XPS were performed at the CIRCE beamline at ALBA Synchrotron with the collaboration of ALBA staff. F. Oropeza Palacio and Rim C.J. van de Poll are acknowledged for the help with RPES measurements.; esteem3reported; esteem3jra | Approved | Most recent IF: 37.8 | ||
Call Number | EMAT @ emat @c:irua:192068 | Serial | 7230 | ||
Permanent link to this record |