“Gliding Arc Plasmatron: Providing an Alternative Method for Carbon Dioxide Conversion”. Ramakers M, Trenchev G, Heijkers S, Wang W, Bogaerts A, Chemsuschem 10, 2642 (2017). http://doi.org/10.1002/cssc.201700589
Abstract: Low-temperature plasmas are gaining a lot of interest for environmental and energy applications. A large research field in these applications is the conversion of CO2 into chemicals and fuels. Since CO2 is a very stable molecule, a key performance indicator for the research on plasma-based CO2 conversion is the energy efficiency. Until now, the energy efficiency in atmospheric plasma reactors is quite low, and therefore we employ here a novel type of plasma reactor, the gliding arc plasmatron (GAP). This paper provides a detailed experimental and computational study of the CO2 conversion, as well as the energy cost and efficiency in a GAP. A comparison with thermal conversion, other plasma types and other novel CO2 conversion technologies is made to find out whether this novel plasma reactor can provide a significant contribution to the much-needed efficient conversion of CO2. From these comparisons it becomes evident that our results are less than a factor of two away from being cost competitive and already outperform several other new technologies. Furthermore, we indicate how the performance of the GAP can still be improved by further exploiting its non-equilibrium character. Hence, it is clear that the GAP is very promising for CO2 conversion.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.226
Times cited: 42
DOI: 10.1002/cssc.201700589
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“Gliding arc plasma for CO 2 conversion: Better insights by a combined experimental and modelling approach”. Wang W, Mei D, Tu X, Bogaerts A, Chemical engineering journal 330, 11 (2017). http://doi.org/10.1016/j.cej.2017.07.133
Abstract: A gliding arc plasma is a potential way to convert CO2 into CO and O2, due to its non-equilibrium character, but little is known about the underlying mechanisms. In this paper, a self-consistent two-dimensional (2D) gliding arc model is developed, with a detailed non-equilibrium CO2 plasma chemistry, and validated with experiments. Our calculated values of the electron number density in the plasma, the CO2 conversion and energy efficiency show reasonable agreement with the experiments, indicating that the model can provide a realistic picture of the plasma chemistry. Comparison of the results with classical thermal conversion, as well as other plasma-based technologies for CO2 conversion reported in literature, demonstrates the non-equilibrium character of the gliding arc, and indicates that the gliding arc is a promising plasma reactor for CO2 conversion. However, some process modifications should be exploited to further improve its performance. As the model provides a realistic picture of the plasma behaviour, we use it first to investigate the plasma characteristics in a whole gliding arc cycle, which is necessary to understand the underlying mechanisms. Subsequently, we perform a chemical kinetics analysis, to investigate the different pathways for CO2 loss and formation. Based on the revealed discharge properties and the underlying CO2 plasma chemistry, the model allows us to propose solutions on how to further improve the
CO2 conversion and energy efficiency by a gliding arc plasma.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 38
DOI: 10.1016/j.cej.2017.07.133
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“Giant magnetoresistance in the half-metallic double-perovskite ferrimagnet Mn2FeReO6”. Li MR, Retuerto M, Deng Z, Stephens PW, Croft M, Huang Q, Wu H, Deng X, Kotliar G, Sánchez-Benítez J, Hadermann J, Walker D, Greenblatt M;, Angewandte Chemie: international edition in English 54, 12069 (2015). http://doi.org/10.1002/anie.201506456
Abstract: The first transition-metal-only double perovskite compound, Mn2+ Fe-2(3+) Re5+ O-6, with 17 unpaired d electrons displays ferrimagnetic ordering up to 520K and a giant positive magnetoresistance of up to 220% at 5K and 8 T. These properties result from the ferrimagnetically coupled Fe and Re sublattice and are affected by a two-to-one magnetic-structure transition of the Mn sublattice when a magnetic field is applied. Theoretical calculations indicate that the half-metallic state can be mainly attributed to the spin polarization of the Fe and Re sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
DOI: 10.1002/anie.201506456
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“Geometry errors in 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 13, 225 (1973). http://doi.org/10.1007/BF02514126
Abstract: The effects of inaccurate sample sizes and sample positioning on 14 MeV neutron activation analysis results are estimated for 30, 20 and 10 mm diameter targets. It appears that axial positioning is the most critical parameter and that using a larger tritium target will yield an overall improvement of the reproducibility.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02514126
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“Geometry and electronic structure of porphyrines and porphyrazines”. Lamoen D, Parrinello M, Chemical Physics Letters 248, 309 (1996)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
Impact Factor: 1.897
Times cited: 46
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“Geochemistry of suspended matter from the Baltic Sea: 2: results of bulk trace metal analysis by AAS”. Brügmann L, Bernard PC, Van Grieken R, Marine chemistry 38, 303 (1992). http://doi.org/10.1016/0304-4203(92)90039-D
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(92)90039-D
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“Geochemistry of suspended matter from the baltic sea : 1 : results of individual particle characterization by automated electron microprobe”. Bernard PC, Van Grieken RE, Brügmann L, Marine chemistry 26, 155 (1989). http://doi.org/10.1016/0304-4203(89)90058-3
Abstract: Automated electron probe X-ray microanalysis was used to characterize some 15 000 individual suspension particles from 50 samples of suspended matter collected from different depths at 18 stations throughout the Baltic Sea and the transient area to the North Sea. For each particle, 14 minor and major elements were determined and size information data were obtained. To process this huge amount of results, multivariate analysis techniques were invoked: the particles were classified into specific types and the abundance variations of these groups were studied. It appeared that 80% of all investigated particles contained mostly silicon, and seemed to consist of quartz, and K-rich and Fe-rich aluminosilicates. The abundance of BaSO4 particles averaged 5% throughout the Baltic Sea, but amounted to up to 44% at some stations. The abundance of the Fe-rich particles varied significantly with location and depth, and averaged ∼ 4%. They were often found to be associated with significant amounts of P. Both of these particle types and the Mn-rich particles are thought to be mainly authigenic. Calcium carbonate particles are more abundant towards the North Sea (which seems to act as a source). Principal component analysis of the data revealed that most of the compositional variability can be explained by differences between deep and surface waters and by the influences of inflowing North Sea waters. Additional information about the types and sources of the suspended matter in the Baltic Sea was gained from the comparison and correlation of the single particle results with different fractions of the bulk concentrations of elements such as Al, Ca, Mn, Fe, Zn and Ba.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(89)90058-3
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“Geochemical characterization of recent sediments in the Baltic Sea by bulk and electron microprobe analysis”. Belmans F, Van Grieken R, Brügmann L, Marine chemistry 42, 223 (1993). http://doi.org/10.1016/0304-4203(93)90014-F
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(93)90014-F
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“Gel-based morphological design of zirconium metal-organic frameworks”. Bueken B, Van Velthoven N, Willhammar T, Stassin T, Stassen I, Keen DA, Baron GV, Denayer JFM, Ameloot R, Bals S, De Vos D, Bennett TD, Chemical science 8, 3939 (2017). http://doi.org/10.1039/C6SC05602D
Abstract: The ability of metal-organic frameworks (MOFs) to gelate under specific synthetic conditions opens up new opportunities in the preparation and shaping of hierarchically porous MOF monoliths, which could be directly implemented for catalytic and adsorptive applications. In this work, we present the first examples of xero-or aerogel monoliths consisting solely of nanoparticles of several prototypical Zr4+-based MOFs: UiO-66-X (X – H, NH2, NO2, (OH)(2)), UiO-67, MOF-801, MOF-808 and NU-1000. High reactant and water concentrations during synthesis were observed to induce the formation of gels, which were converted to monolithic materials by drying in air or supercritical CO2. Electron microscopy, combined with N-2 physisorption experiments, was used to show that irregular nanoparticle packing leads to pure MOF monoliths with hierarchical pore systems, featuring both intraparticle micropores and interparticle mesopores. Finally, UiO-66 gels were shaped into monolithic spheres of 600 mm diameter using an oil-drop method, creating promising candidates for packed-bed catalytic or adsorptive applications, where hierarchical pore systems can greatly mitigate mass transfer limitations.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.668
Times cited: 168
DOI: 10.1039/C6SC05602D
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“Gas-solid hydrodynamics in a stator-rotor vortex chamber reactor”. Lang X, Ouyang Y, Vandewalle LA, Goshayeshi B, Chen S, Madanikashani S, Perreault P, Van Geem KM, van Geem KM, Chemical engineering journal 446, 137323 (2022). http://doi.org/10.1016/J.CEJ.2022.137323
Abstract: The gas-solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid's kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics. A constructed fluidization flow regime map for a fixed solids loading of 100 g shows that the bed can only be fluidized for a rotation speed between 200 and 400 RPM. Below 200 RPM, particles settle down on the bottom plate and cannot form a stable bed due to inertia and friction. Above 400 RPM, the bed cannot be fluidized with superficial velocities up to 1.8 m/s (air flow rate of 90 Nm(3)/h). The bed thickness shows some non-uniformities, being smaller at the top of the bed than at the bottom counterpart. However by increasing the air flow rate or rotation speed the axial nonuniformity can be resolved. The bed pressure drop first increases with increasing gas flow rate and then levels off, showing similar characteristics as conventional fluidized beds. Theoretical pressure drops calculated from mathematical models such as Kao et al. model agree well with experimental measurements. Particle velocity discrepancies between the top and bottom particles reveal that the impact of gravity cannot be completely neglected. Design guidelines and possible applications for further development of STARVOC concept are proposed based on fundamental data provided in this work.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 15.1
DOI: 10.1016/J.CEJ.2022.137323
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“Gas-phase synthesis of Mg-Ti nanoparticles for solid-state hydrogen storage”. Calizzi M, Venturi F, Ponthieu M, Cuevas F, Morandi V, Perkisas T, Bals S, Pasquini L, Physical chemistry, chemical physics 18, 141 (2016). http://doi.org/10.1039/c5cp03092g
Abstract: Mg-Ti nanostructured samples with different Ti contents were prepared via compaction of nanoparticles grown by inert gas condensation with independent Mg and Ti vapour sources. The growth set-up offered the option to perform in situ hydrogen absorption before compaction. Structural and morphological characterisation was carried out by X-ray diffraction, energy dispersive spectroscopy and electron microscopy. The formation of an extended metastable solid solution of Ti in hcp Mg was detected up to 15 at% Ti in the as-grown nanoparticles, while after in situ hydrogen absorption, phase separation between MgH2 and TiH2 was observed. At a Ti content of 22 at%, a metastable Mg-Ti-H fcc phase was observed after in situ hydrogen absorption. The co-evaporation of Mg and Ti inhibited nanoparticle coalescence and crystallite growth in comparison with the evaporation of Mg only. In situ hydrogen absorption was beneficial to subsequent hydrogen behaviour, studied by high pressure differential scanning calorimetry and isothermal kinetics. A transformed fraction of 90% was reached within 100 s at 300 degrees C during both hydrogen absorption and desorption. The enthalpy of hydride formation was not observed to differ from bulk MgH2.
Keywords: A1 Journal article; Engineering Management (ENM); Electron microscopy for materials research (EMAT)
Impact Factor: 4.123
Times cited: 31
DOI: 10.1039/c5cp03092g
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“Gas-phase loading of [Zn4O(btb)2] (MOF-177) with organometallic CVD-precursors: inclusion compounds of the type [LnM]a@MOF-177 and the formation of Cu and Pd nanoparticles inside MOF-177”. Müller M, Lebedev OI, Fischer RA, Journal of materials chemistry 18, 5274 (2008). http://doi.org/10.1039/b810989c
Abstract: The highly porous and desolvated (activated) coordination polymer [Zn4O(btb)2] (btb = benzene-1,3,5-tribenzoate; MOF-177) was loaded with the organometallic compounds [Cp2Fe], [Cp*2Zn], [Cu(OCHMeCH2NMe2)2], [CpCuL] (L = PMe3, CNtBu) and [CpPd(3-C3H5)] via solvent-free adsorption from the gas-phase. The inclusion compounds of the type [LnM]a@MOF-177, where [LnM] indicates the respective compound and the parameter a denotes the number of molecules per formula unit of the MOF-177, were characterised by elemental analysis, FT-IR, solid-state NMR spectroscopy and by powder X-ray diffraction (PXRD). Remarkably high effective loadings of up to 11 molecules [Cp2Fe] and 10 molecules [CpPd(3-C3H5)] per cavity were determined. The analytical data prove that the host lattice and the guest molecules interact only by weak van-der-Waals forces without any significant change of the framework or the chemical nature of the included molecules. Cu nanoparticles showing the typical surface plasmon resonance at 580 nm and Pd nanoparticles of about 2.6 nm in size were formed inside the cavities of MOF-177 by the thermally activated hydrogenolysis of the inclusion compounds [CpCuCNtBu]2@MOF-177 and by photolysis of [CpPd(3-C3H5)]10@MOF-177 in an inert atmosphere (Ar). PXRD, FT-IR and NMR studies revealed that the MOF-177 matrix remained unchanged during the decomposition process of the precursors. N2 adsorption studies of the obtained materials Cu@MOF-177 (e.g. 10.6 wt.% Cu, 2309 m2 g-1) and Pd@MOF-177 (e.g. 32.5 wt.%, 1063 m2 g-1) reveal high remaining specific surface areas (Langmuir model).
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 65
DOI: 10.1039/b810989c
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“Gas phase photocatalytic spiral reactor for fast and efficient pollutant degradation”. Blommaerts N, Asapu R, Claes N, Bals S, Lenaerts S, Verbruggen SW, Chemical engineering journal 316, 850 (2017). http://doi.org/10.1016/j.cej.2017.02.038
Abstract: Photocatalytic reactors for the degradation of gaseous organic pollutants often suffer from major limitations such as small reaction area, sub-optimal irradiation conditions and thus limited reaction rate. In this work, an alternative solution is presented that involves a glass tube coated on the inside with (silvermodified) TiO2 and spiraled around a UVA lamp. First, the spiral reactor is coated from the inside with TiO2 using an experimentally verified procedure that is optimized toward UV light transmission. This procedure is kept as simple as possible and involves a single casting step of a 1 wt% suspension of TiO2 in ethanol through the spiral. This results in a coated tube that absorbs nearly all incident UV light under the experimental conditions used. The optimized coated spiral reactor is then benchmarked to a conventional annular photoreactor of the same outer dimensions and total catalyst loading over a broad range of experimental conditions. Although residence time distribution experiments indicate slightly longer dwelling of molecules in the spiral reactor, no significant difference in by-passing of gas between the spiral reactor and the annular reactor can be claimed. Acetaldehyde degradation efficiency of 100% is obtained with the spiral reactor for a residence time as low as 60 s, whereas the annular reactor could not achieve full degradation even at 1000 s residence time. In a final case study, addition of long-term stable silver nanoparticles, protected by an ultra-thin polymer shell applied via the layer-by-layer (LbL) method, to the spiral reactor coating is shown to double the degradation efficiency and provides an interesting strategy to cope with higher pollutant concentrations without changing the overall dimensions.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 6.216
Times cited: 30
DOI: 10.1016/j.cej.2017.02.038
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“GaN@ZIF-8 : selective formation of gallium nitride quantum dots inside a zinc methylimidazolate framework”. Esken D, Turner S, Wiktor C, Kalidindi SB, Van Tendeloo G, Fischer RA, Journal of the American Chemical Society 133, 16370 (2011). http://doi.org/10.1021/ja207077u
Abstract: The microporous zeolitic imidazolate framework [Zn(MeIM)2; ZIF-8; MeIM = imidazolate-2-methyl] was quantitatively loaded with trimethylamine gallane [(CH3)3NGaH3]. The obtained inclusion compound [(CH3)3NGaH3]@ZIF-8 reveals three precursor molecules per host cavity. Treatment with ammonia selectively yields the caged cyclotrigallazane intermediate (H2GaNH2)3@ZIF-8, and further annealing gives GaN@ZIF-8. This new composite material was characterized with FT-IR spectroscopy, solid-state NMR spectroscopy, powder X-ray diffraction, elemental analysis, (scanning) transmission electron microscopy combined with electron energy-loss spectroscopy, photoluminescence (PL) spectroscopy, and N2 sorption measurements. The data give evidence for the presence of GaN nanoparticles (13 nm) embedded in the cavities of ZIF-8, including a blue-shift of the PL emission band caused by the quantum size effect.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 82
DOI: 10.1021/ja207077u
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“Galvanic Replacement Coupled to Seeded Growth as a Route for Shape-Controlled Synthesis of Plasmonic Nanorattles”. Polavarapu L, Zanaga D, Altantzis T, Rodal-Cedeira S, Pastoriza-Santos I, Pérez-Juste J, Bals S, Liz-Marzán LM, Journal of the American Chemical Society 138, 11453 (2016). http://doi.org/10.1021/jacs.6b06706
Abstract: Shape-controlled synthesis of metal nanoparticles (NPs) requires mechanistic understanding toward the development of modern nanoscience and nanotechnology. We demonstrate here an unconventional shape transformation of Au@Ag core−shell NPs (nanorods and nanocubes) into octahedral nanorattles via roomtemperature galvanic replacement coupled with seeded growth. The corresponding morphological and chemical transformations were investigated in three dimensions, using state-of-the-art X-ray energy-dispersive spectroscopy (XEDS) tomography. The addition of a reducing agent (ascorbic acid) plays a key role in this unconventional mechanistic path, in which galvanic replacement is found to dominate initially when the shell is made of Ag, while seeded growth suppresses transmetalation when a composition of Au:Ag (∼60:40) is reached in the shell, as revealed by quantitative XEDS tomography. This work not only opens new avenues toward the shape control of hollow NPs beyond the morphology of sacrificial templates, but also expands our understanding of chemical transformations in nanoscale galvanic replacement reactions. The XEDS electron tomography study presented here can be generally applied to investigate a wide range of nanoscale morphological and chemical transformations.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 75
DOI: 10.1021/jacs.6b06706
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“Gallium oxide nanorods : novel, template-free synthesis and high catalytic activity in epoxidation reactions”. Lueangchaichaweng W, Brooks NR, Fiorilli S, Gobechiya E, Lin K, Li L, Parres-Esclapez S, Javon E, Bals S, Van Tendeloo G, Martens JA, Kirschhock CEA, Jacobs PA, Pescarmona PP;, Angewandte Chemie: international edition in English 53, 1585 (2014). http://doi.org/10.1002/anie.201308384
Abstract: Gallium oxide nanorods with unprecedented small dimensions (20-80nm length and 3-5nm width) were prepared using a novel, template-free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H2O2, rivaling the industrial benchmark microporous titanosilicate TS-1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 61
DOI: 10.1002/anie.201308384
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“Gaining new insight into low-temperature aqueous photochemical solution deposited ferroelectric PbTiO3 films”. De Dobbelaere C, Lourdes Calzada M, Bretos I, Jimenez R, Ricote J, Hadermann J, Hardy A, Van Bael MK, Materials chemistry and physics 174, 28 (2016). http://doi.org/10.1016/J.MATCHEMPHYS.2016.02.047
Abstract: The nature of the low-temperature photochemical assisted formation process of ferroelectric lead titanate (PbTiO3) films is studied in the present work. Films are obtained by the deposition of an aqueous solution containing citric acid based (citrato) metal ion complexes with intrinsic UV activity. This UV activity is crucial for the aqueous photochemical solution deposition (aqueous PCSD) route being used. UV irradiation enhances the early decomposition of organics and results in improved electrical properties for the crystalline oxide film, even if the film is crystallized at low temperature. GATR-FTIR shows that UV irradiation promotes the decomposition of organic precursor components, resulting in homogeneous films if applied in the right temperature window during film processing. The organic content, morphology and crystallinity of the irradiated films, achieved at different processing atmospheres and temperatures, is studied and eventually correlated to the functional behavior of the obtained films. This is an important issue, as crystalline films obtained at low temperatures often lack ferroelectric responses. In this work, the film prepared in pure oxygen at the very low temperature of 400 degrees C and after an optimized UV treatment presents a significant remanent polarization value of P-r = 8.8 mu C cm(-2). This value is attributed to the better crystallinity, the larger grain size and the reduced porosity obtained thanks to the early film crystallization effectively achieved through the UV treatment in oxygen. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.084
Times cited: 4
DOI: 10.1016/J.MATCHEMPHYS.2016.02.047
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“Fully inorganic Ruddlesden-Popper double CI-I and triple CI-Br-I lead halide perovskite nanocrystals”. Akkerman QA, Bladt E, Petralanda U, Dang Z, Sartori E, Baranov D, Abdelhady AL, Infante I, Bals S, Manna L, Chemistry of materials 31, 2182 (2019). http://doi.org/10.1021/ACS.CHEMMATER.9B00489
Abstract: The vast majority of lead halide perovskite (LHP) nanocrystals (NCs) are currently based on either a single halide composition (CsPbCl3, CsPbBr3, and CsPbI3) or an alloyed mixture of bromide with either Cl- or I- [i.e., CsPb(Br:Cl)(3) or CsPb(Br:I)(3)]. In this work, we present the synthesis as well as a detailed optical and structural study of two halide alloying cases that have not previously been reported for LHP NCs: Cs2PbI2Cl2 NCs and triple halide CsPb(Cl:Br:I)(3) NCs. In the case of Cs2PbI2Cl2, we observe for the first time NCs with a fully inorganic Ruddlesden-Popper phase (RPP) crystal structure. Unlike the well-explored organic-inorganic RPP, here, the RPP formation is triggered by the size difference between the halide ions. These NCs exhibit a strong excitonic absorption, albeit with a weak photoluminescence quantum yield (PLQY). In the case of the triple halide CsPb(Cl:Br:I)(3) composition, the NCs comprise a CsPbBr2Cl perovskite crystal lattice with only a small amount of incorporated iodide, which segregates at RPP planes' interfaces within the CsPb(Cl:Br:I)(3) NCs. Supported by density functional theory calculations and postsynthetic surface treatments to enhance the PLQY, we show that the combination of iodide segregation and defective RPP interfaces are most likely linked to the strong PL quenching observed in these nanostructures. In summary, this work demonstrates the limits of halide alloying in LHP NCs because a mixture that contains halide ions of very different sizes leads to the formation of defective RPP interfaces and a severe quenching of LHP NC's optical properties.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 58
DOI: 10.1021/ACS.CHEMMATER.9B00489
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“Fullerenen: een nieuwe vorm van koolstof”. Van Tendeloo G, Echo 3: essays voor chemie-onderwijs , 79 (1995)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
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“Fullerene-C60 sensor for ultra-high sensitive detection of bisphenol-A and its treatment by green technology”. Rather JA, De Wael K, Sensors and actuators : B : chemical 176, 110 (2013). http://doi.org/10.1016/J.SNB.2012.08.081
Abstract: Endocrine disruptors (EDCs) are environmental pollutants that, once incorporated into an organism, affect the hormonal balance of humans and various species. Its presence in environment is of great importance in water quality related questions. The proposed method describes the development of an accurate, sensitive and selective sensor for the detection of bisphenol-A (BPA) and its treatment by green technology. A fullerene (C60) fabricated electrochemical sensor was developed for the ultrasensitive detection of BPA. The homemade sensor was characterized by scanning electron microscopy, electrochemical impedance spectroscopy and chronocoulometry. The influence of measuring parameters such as pH and C60 loading on the analytical performance of the sensor was evaluated. Various kinetic parameters such as electron transfer number (n); charge transfer coefficient (α); electrode surface area (A) and diffusion coefficient (D) were also calculated. Under the optimal conditions, the oxidation peak current was linear over the concentration range of 74 nM to 0.23 μM with the detection limit (LOD) of 3.7 nM. The fabricated sensor was successfully applied to the determination of BPA in wastewater samples and it has promising analytical applications for the direct determination of BPA at trace level.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 5.401
Times cited: 79
DOI: 10.1016/J.SNB.2012.08.081
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“Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites”. Abakumov AM, Erni R, Tsirlin AA, Rossell MD, Batuk D, Nénert G, Van Tendeloo G, Chemistry of materials 25, 2670 (2013). http://doi.org/10.1021/cm4012052
Abstract: Perovskite-structured titanates with layered A-site ordering form remarkably complex superstructures. Using transmission electron microscopy, synchrotron X-ray and neutron powder diffraction, and ab initio structure relaxation, we present the structural solution of the incommensurately modulated Li3xNd2/3xTiO3 perovskites (x = 0.05, superspace group Pmmm(α1,1/2,0)000(1/2,β2 0)000, a = 3.831048(5) Å, b = 3.827977(4) Å, c = 7.724356(8) Å, q1 = 0.45131(8)a* + 1/2b*, q2 = 1/2a* + 0.41923(4)b*). In contrast to earlier conjectures on the nanoscale compositional phase separation in these materials, all peculiarities of the superstructure can be understood in terms of displacive modulations related to an intricate octahedral tilting pattern. It involves fragmenting the pattern of the out-of-phase tilted TiO6 octahedra around the a- and b-axes into antiphase domains, superimposed on the pattern of domains with either pronounced or suppressed in-phase tilt component around the c-axis. The octahedral tilting competes with the second order JahnTeller distortion of the TiO6 octahedra. This competition is considered as the primary driving force for the modulated structure. The A cations are suspected to play a role in this modulation affecting it mainly through the tolerance factor and the size variance. The reported crystal structure calls for a revision of the structure models proposed for the family of layered A-site ordered perovskites exhibiting a similar type of modulated structure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 23
DOI: 10.1021/cm4012052
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“From spin induced ferroelectricity to dipolar glasses : spinel chromites and mixed delafossites”. Maignan A, Martin C, Singh K, Simon C, Lebedev OI, Turner S, Journal of solid state chemistry 195, 41 (2012). http://doi.org/10.1016/j.jssc.2012.01.063
Abstract: Magnetoelectric multiferroics showing coupling between polarization and magnetic order are attracting much attention. For instance, they could be used in memory devices. Metal-transition oxides are provided several examples of inorganic magnetoelectric multiferroics. In the present short review, spinel and delafossite chromites are described. For the former, an electric polarization is evidenced in the ferrimagnetic state for ACr2O4 polycrystalline samples (A=Ni, Fe, Co). The presence of a JahnTeller cation such as Ni2+ at the A site is shown to yield larger polarization values. In the delafossites, substitution by V3+ at the Cr or Fe site in CuCrO2 (CuFeO2) suppresses the complex antiferromagnetic structure at the benefit of a spin glass state. The presence of cation disorder, probed by transmission electron microscopy, favors relaxor-like ferroelectricity. The results on the ferroelectricity of ferrimagnets and insulating spin glasses demonstrate that, in this research field, transition-metal oxides are worth to be studied.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 27
DOI: 10.1016/j.jssc.2012.01.063
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“From precursor powders to CsPbX3 perovskite nanowires : one-pot synthesis, growth mechanism, and oriented self-assembly”. Tong Y, Bohn BJ, Bladt E, Wang K, Mueller-Buschbaum P, Bals S, Urban AS, Polavarapu L, Feldmann J, Angewandte Chemie: international edition in English 56, 13887 (2017). http://doi.org/10.1002/ANIE.201707224
Abstract: <script type='text/javascript'>document.write(unpmarked('The colloidal synthesis and assembly of semiconductor nanowires continues to attract a great deal of interest. Herein, we describe the single-step ligand-mediated synthesis of single-crystalline CsPbBr3 perovskite nanowires (NWs) directly from the precursor powders. Studies of the reaction process and the morphological evolution revealed that the initially formed CsPbBr3 nanocubes are transformed into NWs through an oriented-attachment mechanism. The optical properties of the NWs can be tuned across the entire visible range by varying the halide (Cl, Br, and I) composition through subsequent halide ion exchange. Single-particle studies showed that these NWs exhibit strongly polarized emission with a polarization anisotropy of 0.36. More importantly, the NWs can self-assemble in a quasi-oriented fashion at an air/liquid interface. This process should also be easily applicable to perovskite nanocrystals of different morphologies for their integration into nanoscale optoelectronic devices.'));
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
Times cited: 223
DOI: 10.1002/ANIE.201707224
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“From polyester grafting onto POSS nanocage by ring-opening polymerization to high performance polyester/POSS nanocomposites”. Goffin A-L, Duquesne E, Raquez J-M, Miltner HE, Ke X, Alexandre M, Van Tendeloo G, van Mele B, Dubois P, Journal of materials chemistry 20, 9415 (2010). http://doi.org/10.1039/c0jm00283f
Abstract: Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of ε-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins, M. Alexandre, Ph. Dubois, Eur. Polym. Journal, 2007, 43, 4103) were studied as masterbatches by melt-blending within their corresponding commercial polymeric matrices, i.e., poly(ε-caprolactone) (PCL) and poly(L,L-lactide) (PLA). For the sake of comparison, neat POSS nanoparticles were also dispersed in PCL and PLA. The objective was to prepare aliphatic polyester-based nanocomposites with enhanced crystallization behavior, and therefore, enhanced thermo-mechanical properties. Wide-angle X-ray scattering and transmission electron microscopy attested for the dispersion of individualized POSS nanoparticles in the resulting nanocomposite materials only when the polyester-grafted POSS nanohybrid was used as a masterbatch. The large impact of such finely dispersed (grafted) nanoparticles on the crystallization behavior for the corresponding polyester matrices was noticed, as evidenced by differential scanning calorimetry analysis. Indeed, well-dispersed POSS nanoparticles acted as efficient nucleating sites, significantly increasing the crystallinity degree of both PCL and PLA matrices. As a result, a positive impact on thermo-mechanical properties was highlighted by dynamic mechanical thermal analysis.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 42
DOI: 10.1039/c0jm00283f
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“From multi- to single-hollow trimetallic nanocrystals by ultrafast heating”. Manzaneda-Gonzalez V, Jenkinson K, Pena-Rodriguez O, Borrell-Grueiro O, Trivino-Sanchez S, Banares L, Junquera E, Espinosa A, Gonzalez-Rubio G, Bals S, Guerrero-Martinez A, Chemistry of materials 35, 9603 (2023). http://doi.org/10.1021/ACS.CHEMMATER.3C01698
Abstract: Metal nanocrystals (NCs) display unique physicochemical features that are highly dependent on nanoparticle dimensions, anisotropy, structure, and composition. The development of synthesis methodologies that allow us to tune such parameters finely emerges as crucial for the application of metal NCs in catalysis, optical materials, or biomedicine. Here, we describe a synthetic methodology to fabricate hollow multimetallic heterostructures using a combination of seed-mediated growth routes and femtosecond-pulsed laser irradiation. The envisaged methodology relies on the coreduction of Ag and Pd ions on gold nanorods (Au NRs) to form Au@PdAg core-shell nanostructures containing small cavities at the Au-PdAg interface. The excitation of Au@PdAg NRs with low fluence femtosecond pulses was employed to induce the coalescence and growth of large cavities, forming multihollow anisotropic Au@PdAg nanostructures. Moreover, single-hollow alloy AuPdAg could be achieved in high yield by increasing the irradiation energy. Advanced electron microscopy techniques, energy-dispersive X-ray spectroscopy (EDX) tomography, X-ray absorption near-edge structure (XANES) spectroscopy, and finite differences in the time domain (FDTD) simulations allowed us to characterize the morphology, structure, and elemental distribution of the irradiated NCs in detail. The ability of the reported synthesis route to fabricate multimetallic NCs with unprecedented hollow nanostructures offers attractive prospects for the fabrication of tailored high-entropy alloy nanoparticles.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.6
Times cited: 2
DOI: 10.1021/ACS.CHEMMATER.3C01698
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“From CdSe nanoplatelets to quantum rings by thermochemical edge reconfiguration”. Salzmann BBV, Vliem JF, Maaskant DN, Post LC, Li C, Bals S, Vanmaekelbergh D, Chemistry Of Materials 33, 6853 (2021). http://doi.org/10.1021/ACS.CHEMMATER.1C01618
Abstract: The variation in the shape of colloidal semiconductor nanocrystals (NCs) remains intriguing. This interest goes beyond crystallography as the shape of the NC determines its energy levels and optoelectronic properties. While thermodynamic arguments point to a few or just a single shape(s), terminated by the most stable crystal facets, a remarkable variation in NC shape has been reported for many different compounds. For instance, for the well-studied case of CdSe, close-to-spherical quantum dots, rods, two-dimensional nanoplatelets, and quantum rings have been reported. Here, we report how two-dimensional CdSe nanoplatelets reshape into quantum rings. We monitor the reshaping in real time by combining atomically resolved structural characterization with optical absorption and photoluminescence spectroscopy. We observe that CdSe units leave the vertical sides of the edges and recrystallize on the top and bottom edges of the nanoplatelets, resulting in a thickening of the rims. The formation of a central hole, rendering the shape into a ring, only occurs at a more elevated temperature.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 7
DOI: 10.1021/ACS.CHEMMATER.1C01618
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“From Bi4V2O11 to Bi4V2O10.66: the VV-VIV transformation in the Aurovillius-type framework”. Huvé, M, Vannier R-N, Nowogrocki G, Mairesse G, Van Tendeloo G, Journal of materials chemistry 6, 1339 (1996). http://doi.org/10.1039/jm9960601339
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 63
DOI: 10.1039/jm9960601339
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“From anisole to 1,2,4,5-tetramethoxybenzene: theoretical study of the factors that determine the conformation of methoxy groups on a benzene ring”. Vande Velde C, Bultinck E, Tersago K, van Alsenoy C, Blockhuys F, International journal of quantum chemistry 107, 670 (2007). http://doi.org/10.1002/qua.21183
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.92
Times cited: 14
DOI: 10.1002/qua.21183
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“From 2D to 3D : bridging self-assembled monolayers to a substrate-induced polymorph in a molecular semiconductor”. Hao Y, Velpula G, Kaltenegger M, Bodlos WR, Vibert F, Mali KS, De Feyter S, Resel R, Geerts YH, Van Aert S, Beljonne D, Lazzaroni R, Chemistry of materials 34, 2238 (2022). http://doi.org/10.1021/ACS.CHEMMATER.1C04038
Abstract: In this study, a new bottom-up approach is proposed to predict the crystal structure of the substrate-induced polymorph (SIP) of an archetypal molecular semiconductor. In spite of intense efforts, the formation mechanism of SIPs is still not fully understood, and predicting their crystal structure is a very delicate task. Here, we selected lead phthalocyanine (PbPc) as a prototypical molecular material because it is a highly symmetrical yet nonplanar molecule and we demonstrate that the growth and crystal structure of the PbPc SIPs can be templated by the corresponding physisorbed self-assembled molecular networks (SAMNs). Starting from SAMNs of PbPc formed at the solution/graphite interface, the structural and energetic aspects of the assembly were studied by a combination of in situ scanning tunneling microscopy and multiscale computational chemistry approach. Then, the growth of a PbPc SIP on top of the physisorbed monolayer was modeled without prior experimental knowledge, from which the crystal structure of the SIP was predicted. The theoretical prediction of the SIP was verified by determining the crystal structure of PbPc thin films using X-ray diffraction techniques, revealing the formation of a new polymorph of PbPc on the graphite substrate. This study clearly illustrates the correlation between the SAMNs and SIPs, which are traditionally considered as two separate but conceptually connected research areas. This approach is applicable to molecular materials in general to predict the crystal structure of their SIPs.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.6
DOI: 10.1021/ACS.CHEMMATER.1C04038
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“Free energy barriers from biased molecular dynamics simulations”. Bal KM, Fukuhara S, Shibuta Y, Neyts EC, Journal Of Chemical Physics 153, 114118 (2020). http://doi.org/10.1063/5.0020240
Abstract: Atomistic simulation methods for the quantification of free energies are in wide use. These methods operate by sampling the probability density of a system along a small set of suitable collective variables (CVs), which is, in turn, expressed in the form of a free energy surface (FES). This definition of the FES can capture the relative stability of metastable states but not that of the transition state because the barrier height is not invariant to the choice of CVs. Free energy barriers therefore cannot be consistently computed from the FES. Here, we present a simple approach to calculate the gauge correction necessary to eliminate this inconsistency. Using our procedure, the standard FES as well as its gauge-corrected counterpart can be obtained by reweighing the same simulated trajectory at little additional cost. We apply the method to a number of systems—a particle solvated in a Lennard-Jones fluid, a Diels–Alder reaction, and crystallization of liquid sodium—to demonstrate its ability to produce consistent free energy barriers that correctly capture the kinetics of chemical or physical transformations, and discuss the additional demands it puts on the chosen CVs. Because the FES can be converged at relatively short (sub-ns) time scales, a free energy-based description of reaction kinetics is a particularly attractive option to study chemical processes at more expensive quantum mechanical levels of theory.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.4
DOI: 10.1063/5.0020240
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