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“'On tomorrow's grounds' : Flemish agriculture in 2030: a case of participatory translation of sustainability principles into a vision for the future”. Nevens F, Dessein J, Meul M, Rogge E, Verbruggen I, Mulier A, Van Passel S, Lepoutre J, Hongenaert M, Journal Of Cleaner Production 16, 1062 (2008). http://doi.org/10.1016/J.JCLEPRO.2007.06.007
Abstract: In Flanders (Belgium) there is an obvious lack of clear long-term vision on sustainable development, for society as a whole as well as for the individual sectors of (economic) activity. In this paper we present the first results of a process of vision development for Flemish agriculture, called On tomorrow's grounds. The initiative, taken by Stedula (the Flemish Policy Research Centre for Sustainable Agriculture), shows that discovering core values, stating a concise mission, establishing guiding core principles and working with vivid descriptions of envisaged future systems seem indispensable elements to develop a vision that inspires and mobilizes people and that, eventually, stands a chance of being anchored in the sector's or organisation's culture. The principal method of working of the project was a multi-stakeholder process (MSP) focussed on dialogue. During five extensive stakeholder meetings, representatives of farmers, service industries, food distribution, education, government, research, consumers and NGO's participated in a constructive dialogue on values and mission, principles and two vivid descriptions of envisioned future farms. The concept of the project was welcomed and supported by the Flemish Minister-President and by the Belgian federal state secretary for sustainable development.
Keywords: A1 Journal article; Economics
Impact Factor: 5.715
Times cited: 13
DOI: 10.1016/J.JCLEPRO.2007.06.007
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“Innovative market-based policy instruments for waste management : a case study on shredder residues in Belgium”. Dubois M, Hoogmartens R, Van Passel S, Van Acker K, Vanderreydt I, Waste Management &, Research 33, 886 (2015). http://doi.org/10.1177/0734242X15600053
Abstract: In an increasingly complex waste market, market-based policy instruments, such as disposal taxes, can give incentives for sustainable progress while leaving flexibility for innovation. However, implementation of disposal taxes is often criticised by domestic waste handlers that fear to be outcompeted by competitors in other countries. The article discusses three innovative market-based instruments that limit the impact on international competitiveness: Tradable recycling credits, refunded disposal taxes and differentiated disposal taxes. All three instruments have already been implemented for distinct environmental policies in Europe. In order to illustrate how these instruments can be used for waste policy, the literature review is complemented with a case study on shredder residues from metal-containing waste streams in Belgium. The analysis shows that a conventional disposal tax remains the most efficient, simple and transparent instrument. However, if international competition is a significant issue or if political support is weak, refunded and differentiated disposal taxes can have an added value as second-best instruments. Tradable recycling credits are not an appropriate instrument for use in small waste markets with market power. In addition, refunded taxes create similar incentives, but induce lower transactions costs.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 1.803
Times cited: 1
DOI: 10.1177/0734242X15600053
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“Manipulating topological transformations of polar structures through real-time observation of the dynamic polarization evolution”. Du K, Zhang M, Dai C, Zhou ZN, Xie YW, Ren ZH, Tian H, Chen LQ, Van Tendeloo G, Zhang Z, Nature communications 10, 4864 (2019). http://doi.org/10.1038/S41467-019-12864-5
Abstract: Topological structures based on controllable ferroelectric or ferromagnetic domain configurations offer the opportunity to develop microelectronic devices such as high-density memories. Despite the increasing experimental and theoretical insights into various domain structures (such as polar spirals, polar wave, polar vortex) over the past decade, manipulating the topological transformations of polar structures and comprehensively understanding its underlying mechanism remains lacking. By conducting an in-situ non-contact bias technique, here we systematically investigate the real-time topological transformations of polar structures in PbTiO3/SrTiO3 multilayers at an atomic level. The procedure of vortex pair splitting and the transformation from polar vortex to polar wave and out-of-plane polarization are observed step by step. Furthermore, the redistribution of charge in various topological structures has been demonstrated under an external bias. This provides new insights for the symbiosis of polar and charge and offers an opportunity for a new generation of microelectronic devices.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.124
DOI: 10.1038/S41467-019-12864-5
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“Improving extracellular vesicles visualization: From static to motion”. Reclusa P, Verstraelen P, Taverna S, Gunasekaran M, Pucci M, Pintelon I, Claes N, de Miguel-Pérez D, Alessandro R, Bals S, Kaushal S, Rolfo C, Scientific Reports 10, 6494 (2020). http://doi.org/10.1038/s41598-020-62920-0
Abstract: In the last decade extracellular vesicles (EVs) have become a hot topic. The findings on EVs content and effects have made them a major field of interest in cancer research. EVs, are able to be internalized through integrins expressed in parental cells, in a tissue specific manner, as a key step of cancer progression and pre-metastatic niche formation. However, this specificity might lead to new opportunities in cancer treatment by using EVs as devices for drug delivery. For future applications of EVs in cancer, improved protocols and methods for EVs isolation and visualization are required. Our group has put efforts on developing a protocol, able to track the EVs for in vivo internalization analysis. We showed, for the first time, the videos of labeled EVs uptake by living lung cancer cells.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.6
Times cited: 25
DOI: 10.1038/s41598-020-62920-0
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“Luminescent Colloidal InSb Quantum Dots from In Situ Generated Single-Source Precursor”. Busatto S, Ruiter M de, Jastrzebski JTBH, Albrecht W, Pinchetti V, Brovelli S, Bals S, Moret M-E, de Mello Donega C, Acs Nano 14, 13146 (2020). http://doi.org/10.1021/acsnano.0c04744
Abstract: Despite recent advances, the synthesis of colloidal InSb quantum dots (QDs) remains underdeveloped, mostly due to the lack of suitable precursors. In this work, we use Lewis acid–base interactions between Sb(III) and In(III) species formed at room temperature in situ from commercially available compounds (viz., InCl3, Sb[NMe2]3 and a primary alkylamine) to obtain InSb adduct complexes. These complexes are successfully used as precursors for the synthesis of colloidal InSb QDs ranging from 2.8 to 18.2 nm in diameter by fast coreduction at sufficiently high temperatures (≥230 °C). Our findings allow us to propose a formation mechanism for the QDs synthesized in our work, which is based on a nonclassical nucleation event, followed by aggregative growth. This yields ensembles with multimodal size distributions, which can be fractionated in subensembles with relatively narrow polydispersity by postsynthetic size fractionation. InSb QDs with diameters below 7.0 nm have the zinc blende crystal structure, while ensembles of larger QDs (≥10 nm) consist of a mixture of wurtzite and zinc blende QDs. The QDs exhibit photoluminescence with small Stokes shifts and short radiative lifetimes, implying that the emission is due to band-edge recombination and that the direct nature of the bandgap of bulk InSb is preserved in InSb QDs. Finally, we constructed a sizing curve correlating the peak position of the lowest energy absorption transition with the QD diameters, which shows that the band gap of colloidal InSb QDs increases with size reduction following a 1/d dependence.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 17.1
Times cited: 21
DOI: 10.1021/acsnano.0c04744
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“Division of labor and growth during electrical cooperation in multicellular cable bacteria”. Geerlings NMJ, Karman C, Trashin S, As KS, Kienhuis MVM, Hidalgo-Martinez S, Vasquez-Cardenas D, Boschker HTS, De Wael K, Middelburg JJ, Polerecky L, Meysman FJR, Proceedings Of The National Academy Of Sciences Of The United States Of America 117, 5478 (2020). http://doi.org/10.1073/PNAS.1916244117
Abstract: Multicellularity is a key evolutionary innovation, leading to coordinated activity and resource sharing among cells, which generally occurs via the physical exchange of chemical compounds. However, filamentous cable bacteria display a unique metabolism in which redox transformations in distant cells are coupled via long-distance electron transport rather than an exchange of chemicals. This challenges our understanding of organismal functioning, as the link among electron transfer, metabolism, energy conservation, and filament growth in cable bacteria remains enigmatic. Here, we show that cells within individual filaments of cable bacteria display a remarkable dichotomy in biosynthesis that coincides with redox zonation. Nanoscale secondary ion mass spectrometry combined with 13 C (bicarbonate and propionate) and 15 N-ammonia isotope labeling reveals that cells performing sulfide oxidation in deeper anoxic horizons have a high assimilation rate, whereas cells performing oxygen reduction in the oxic zone show very little or no label uptake. Accordingly, oxygen reduction appears to merely function as a mechanism to quickly dispense of electrons with little to no energy conservation, while biosynthesis and growth are restricted to sulfide-respiring cells. Still, cells can immediately switch roles when redox conditions change, and show no differentiation, which suggests that the “community service” performed by the cells in the oxic zone is only temporary. Overall, our data reveal a division of labor and electrical cooperation among cells that has not been seen previously in multicellular organisms.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 11.1
Times cited: 6
DOI: 10.1073/PNAS.1916244117
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“Spin polarization in monolayer MoS₂, in the presence of proximity-induced interactions”. Zhao XN, Xu W, Xiao YM, Van Duppen B, International Journal Of Modern Physics C 31, 2050143 (2020). http://doi.org/10.1142/S0129183120501430
Abstract: When monolayer (ML) MoS2 is placed on a substrate, the proximity-induced interactions such as the Rashba spin-orbit coupling (RSOC) and exchange interaction (EI) can be introduced. Thus, the electronic system can behave like a spintronic device. In this study, we present a theoretical study on how the presence of the RSCO and EI can lead to the band splitting, the lifting of the valley degeneracy and to the spin polarization in n- and p-type ML MoS2. We find that the maxima of the in-plane spin orientation in the conduction and valence bands in ML MoS2 depend on the Rashba parameter and the effective Zeeman field factor. At a fixed Rashba parameter, the minima of the split conduction band and the maxima of the split valence band along with the spin polarization in ML MoS2 can be tuned effectively by varying the effective Zeeman field factor. On the basis that the EI can be induced by placing the ML MoS2 on a ferromagnetic substrate or by magnetic doping in ML MoS2, we predict that the interesting spintronic effects can be observed in n- and p-type ML MoS2. This work can be helpful to gain an in-depth understanding of the basic physical properties of ML MoS2 for application in advanced electronic and optoelectronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.9
DOI: 10.1142/S0129183120501430
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“Topological energy barrier for skyrmion lattice formation in MnSi”. Leishman AWD, Menezes RM, Longbons G, Bauer ED, Janoschek M, Honecker D, DeBeer-Schmitt L, White JS, Sokolova A, Milošević, MV, Eskildsen MR, Physical Review B 102, 104416 (2020). http://doi.org/10.1103/PHYSREVB.102.104416
Abstract: We report the direct measurement of the topological skyrmion energy barrier through a hysteresis of the skyrmion lattice in the chiral magnet MnSi. Measurements were made using small-angle neutron scattering with a custom-built resistive coil to allow for high-precision minor hysteresis loops. The experimental data were analyzed using an adapted Preisach model to quantify the energy barrier for skyrmion formation and corroborated by the minimum-energy path analysis based on atomistic spin simulations. We reveal that the skyrmion lattice in MnSi forms from the conical phase progressively in small domains, each of which consisting of hundreds of skyrmions, and with an activation barrier of several eV.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.7
Times cited: 1
DOI: 10.1103/PHYSREVB.102.104416
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“Layer-by-Layer-Stabilized Plasmonic Gold-Silver Nanoparticles on TiO2: Towards Stable Solar Active Photocatalysts”. Dingenen F, Blommaerts N, Van Hal M, Borah R, Arenas-Esteban D, Lenaerts S, Bals S, Verbruggen SW, Nanomaterials 11, 2624 (2021). http://doi.org/10.3390/nano11102624
Abstract: To broaden the activity window of TiO2, a broadband plasmonic photocatalyst has been designed and optimized. This plasmonic ‘rainbow’ photocatalyst consists of TiO2 modified with gold–silver composite nanoparticles of various sizes and compositions, thus inducing a broadband interaction with polychromatic solar light. However, these nanoparticles are inherently unstable, especially due to the use of silver. Hence, in this study the application of the layer-by-layer technique is introduced to create a protective polymer shell around the metal cores with a very high degree of control. Various TiO2 species (pure anatase, PC500, and P25) were loaded with different plasmonic metal loadings (0–2 wt %) in order to identify the most solar active composite materials. The prepared plasmonic photocatalysts were tested towards stearic acid degradation under simulated sunlight. From all materials tested, P25 + 2 wt % of plasmonic ‘rainbow’ nanoparticles proved to be the most promising (56% more efficient compared to pristine P25) and was also identified as the most cost-effective. Further, 2 wt % of layer-by-layer-stabilized ‘rainbow’ nanoparticles were loaded on P25. These layer-by-layer-stabilized metals showed superior stability under a heated oxidative atmosphere, as well as in a salt solution. Finally, the activity of the composite was almost completely retained after 1 month of aging, while the nonstabilized equivalent lost 34% of its initial activity. This work shows for the first time the synergetic application of a plasmonic ‘rainbow’ concept and the layer-by-layer stabilization technique, resulting in a promising solar active, and long-term stable photocatalyst.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 3.553
Times cited: 7
DOI: 10.3390/nano11102624
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“Correlating structure and detection properties in HgTe nanocrystal films”. Chee S-S, Greboval C, Vale Magalhaes D, Ramade J, Chu A, Qu J, Rastogi P, Khalili A, Dang TH, Dabard C, Prado Y, Patriarche G, Chaste J, Rosticher M, Bals S, Delerue C, Lhuillier E, Nano Letters 21, 4145 (2021). http://doi.org/10.1021/ACS.NANOLETT.0C04346
Abstract: HgTe nanocrystals (NCs) enable broadly tunable infrared absorption, now commonly used to design light sensors. This material tends to grow under multipodic shapes and does not present well-defined size distributions. Such point generates traps and reduces the particle packing, leading to a reduced mobility. It is thus highly desirable to comprehensively explore the effect of the shape on their performance. Here, we show, using a combination of electron tomography and tight binding simulations, that the charge dissociation is strong within HgTe NCs, but poorly shape dependent. Then, we design a dual-gate field-effect-transistor made of tripod HgTe NCs and use it to generate a planar p-n junction, offering more tunability than its vertical geometry counterpart. Interestingly, the performance of the tripods is higher than sphere ones, and this can be correlated with a stronger Te excess in the case of sphere shapes which is responsible for a higher hole trap density.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 12.712
Times cited: 20
DOI: 10.1021/ACS.NANOLETT.0C04346
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“Zitterbewegung of moiré, excitons in twisted MoS₂/WSe₂, heterobilayers”. Lavor IR, da Costa DR, Covaci L, Milošević, MV, Peeters FM, Chaves A, Physical review letters 127, 106801 (2021). http://doi.org/10.1103/PHYSREVLETT.127.106801
Abstract: The moire pattern observed in stacked noncommensurate crystal lattices, such as heterobilayers of transition metal dichalcogenides, produces a periodic modulation of their band gap. Excitons subjected to this potential landscape exhibit a band structure that gives rise to a quasiparticle dubbed the moire exciton. In the case of MoS2/WSe2 heterobilayers, the moire trapping potential has honeycomb symmetry and, consequently, the moire exciton band structure is the same as that of a Dirac-Weyl fermion, whose mass can be further tuned down to zero with a perpendicularly applied field. Here we show that, analogously to other Dirac-like particles, the moire exciton exhibits a trembling motion, also known as Zitterbewegung, whose long timescales are compatible with current experimental techniques for exciton dynamics. This promotes the study of the dynamics of moire excitons in van der Waals heterostructures as an advantageous solid-state platform to probe Zitterbewegung, broadly tunable by gating and interlayer twist angle.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Times cited: 5
DOI: 10.1103/PHYSREVLETT.127.106801
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“Electronic transport mechanisms correlated to structural properties of a reduced graphene oxide sponge”. Pinto N, McNaughton B, Minicucci M, Milošević, MV, Perali A, Nanomaterials 11, 2503 (2021). http://doi.org/10.3390/NANO11102503
Abstract: We report morpho-structural properties and charge conduction mechanisms of a foamy “graphene sponge ”, having a density as low as & AP;0.07 kg/m3 and a carbon to oxygen ratio C:O & SIME; 13:1. The spongy texture analysed by scanning electron microscopy is made of irregularly-shaped millimetres-sized small flakes, containing small crystallites with a typical size of & SIME;16.3 nm. A defect density as high as & SIME;2.6 x 1011 cm-2 has been estimated by the Raman intensity of D and G peaks, dominating the spectrum from room temperature down to & SIME;153 K. Despite the high C:O ratio, the graphene sponge exhibits an insulating electrical behavior, with a raise of the resistance value at & SIME;6 K up to 5 orders of magnitude with respect to the room temperature value. A variable range hopping (VRH) conduction, with a strong 2D character, dominates the charge carriers transport, from 300 K down to 20 K. At T < 20 K, graphene sponge resistance tends to saturate, suggesting a temperature-independent quantum tunnelling. The 2D-VRH conduction originates from structural disorder and is consistent with hopping of charge carriers between sp2 defects in the plane, where sp3 clusters related to oxygen functional groups act as potential barriers.</p>
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 3.553
DOI: 10.3390/NANO11102503
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“Metal-polymer heterojunction in colloidal-phase plasmonic catalysis”. Rogolino A, Claes N, Cizaurre J, Marauri A, Jumbo-Nogales A, Lawera Z, Kruse J, Sanroman-Iglesias M, Zarketa I, Calvo U, Jimenez-Izal E, Rakovich YP, Bals S, Matxain JM, Grzelczak M, The journal of physical chemistry letters 13, 2264 (2022). http://doi.org/10.1021/ACS.JPCLETT.1C04242
Abstract: Plasmonic catalysis in the colloidal phase requires robust surface ligands that prevent particles from aggregation in adverse chemical environments and allow carrier flow from reagents to nanoparticles. This work describes the use of a water-soluble conjugated polymer comprising a thiophene moiety as a surface ligand for gold nanoparticles to create a hybrid system that, under the action of visible light, drives the conversion of the biorelevant NAD+ to its highly energetic reduced form NADH. A combination of advanced microscopy techniques and numerical simulations revealed that the robust metal-polymer heterojunction, rich in sulfonate functional groups, directs the interaction of electron-donor molecules with the plasmonic photocatalyst. The tight binding of polymer to the gold surface precludes the need for conventional transition-metal surface cocatalysts, which were previously shown to be essential for photocatalytic NAD(+) reduction but are known to hinder the optical properties of plasmonic nanocrystals. Moreover, computational studies indicated that the coating polymer fosters a closer interaction between the sacrificial electron-donor triethanolamine and the nanoparticles, thus enhancing the reactivity.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.7
Times cited: 1
DOI: 10.1021/ACS.JPCLETT.1C04242
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“NH3and HNOxFormation and Loss in Nitrogen Fixation from Air with Water Vapor by Nonequilibrium Plasma”. Vervloessem E, Gromov M, De Geyter N, Bogaerts A, Gorbanev Y, Nikiforov A, ACS Sustainable Chemistry and Engineering 11, 4289 (2023). http://doi.org/10.1021/acssuschemeng.3c00208
Abstract: The current global energy crisis indicated that increasing our
insight into nonfossil fuel nitrogen fixation pathways for synthetic fertilizer
production is more crucial than ever. Nonequilibrium plasma is a good candidate
because it can use N2 or air as a N source and water directly as a H source, instead
of H2 or fossil fuel (CH4). In this work, we investigate NH3 gas phase formation
pathways from humid N2 and especially humid air up to 2.4 mol % H2O (100%
relative humidity at 20 °C) by optical emission spectroscopy and Fouriertransform
infrared spectroscopy. We demonstrate that the nitrogen fixation
capacity is increased when water vapor is added, as this enables HNO2 and NH3
production in both N2 and air. However, we identified a significant loss
mechanism for NH3 and HNO2 that occurs in systems where these species are
synthesized simultaneously; i.e., downstream from the plasma, HNO2 reacts with NH3 to form NH4NO2, which rapidly decomposes
into N2 and H2O. We also discuss approaches to prevent this loss mechanism, as it reduces the effective nitrogen fixation when not
properly addressed and therefore should be considered in future works aimed at optimizing plasma-based N2 fixation. In-line removal
of HNO2 or direct solvation in liquid are two proposed strategies to suppress this loss mechanism. Indeed, using liquid H2O is
beneficial for accumulation of the N2 fixation products. Finally, in humid air, we also produce NH4NO3, from the reaction of HNO3
with NH3, which is of direct interest for fertilizer application.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 8.4
DOI: 10.1021/acssuschemeng.3c00208
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“Two-dimensional heterostructures formed by graphenelike ZnO and MgO monolayers for optoelectronic applications”. Seyedmohammadzadeh M, Sevik C, Guelseren O, Physical review materials 6, 104004 (2022). http://doi.org/10.1103/PHYSREVMATERIALS.6.104004
Abstract: Two-dimensional heterostructures are an emerging class of materials for novel applications because of extensive engineering potential by tailoring intriguing properties of different layers as well as the ones arising from their interface. A systematic investigation of mechanical, electronic, and optical properties of possible heterostructures formed by bilayer structures graphenelike ZnO and MgO monolayers is presented. Different functionality of each layer makes these heterostructures very appealing for device applications. ZnO layer is convenient for electron transport in these structures, while MgO layer improves electron collection. At the outset, all of the four possible stacking configurations across the heterostructure are mechanically stable. In addition, stability analysis using phonon dispersion reveals that the AB stacking formed by placing the Mg atom on top of the O atom of the ZnO layer is also dynamically stable at zero temperature. Henceforth, we have investigated the optical properties of these stable heterostructures by applying many-body perturbation theory within the framework of GW approximation and solving the Bethe-Salpeter equation. It is demonstrated that strong excitonic effects reduce the optical band gap to the visible light spectrum range. These results show that this new two-dimensional form of ZnO/MgO heterostructures open an avenue for novel optoelectronic device applications.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.4
DOI: 10.1103/PHYSREVMATERIALS.6.104004
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“Background aerosol composition in the Namib Desert, South West-Africa (Namibia)”. Annegarn HJ, Van Grieken RE, Dibby DM, Von Blottnitz F, Atmospheric environment : an international journal 17, 2045 (1983). http://doi.org/10.1016/0004-6981(83)90361-X
Abstract: A remote site in the Namib Desert was selected for sampling background aerosols in southern Africa, as one of a wide network of stations spanning the Southern Hemisphere in a programme designed to measure the background concentrations of trace elements in the atmosphere. A series of samples was collected over a 6-month period using a single-orifice cascade impactor, which fractionated the particles into six size groups. Analysis was performed using particle-induced X-ray emission (PIXE), yielding results for S, Cl, K, Ca, Ti, Mn, Fe, Br and Sr, and occasionally also for V, Cr, Ni, Cu, Zn and Pb. No direct correlations with wind direction were observed excluding strong local or regional sources of particles. K, Ca, Ti, Mn and Fe can be identified with a dust dispersion source. Cl, large particle S and Br, and part of the K and Sr are derived from sea spray. Relative to the soil components small particle K is not enriched as it normally is in regions with less scarce vegetation. Cr, V, Ni, Cu, Zn and Pb concentrations and enrichments in the aerosol are lower than practically all values measured at any other location hitherto. The concentration of the small particle sulphur, 200 ng m−3, is believed to be related to anaerobic conditions and plankton blooms in the ocean upwelling zones off Namibia.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0004-6981(83)90361-X
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“Combined 1D, 2D and 3D micro-XRF techniques for the analysis of illuminated manuscripts”. Lachmann T, van der Snickt G, Haschke M, Mantouvalou I, Journal of analytical atomic spectrometry 31, 1989 (2016). http://doi.org/10.1039/C6JA00220J
Abstract: The combination of several micro-XRF analysis modes is presented for the investigation of an illuminated parchment manuscript. With a commercial instrument, conventional micro-XRF spot analysis (0D) and mapping (2D) are performed, yielding detailed lateral elemental information. Depth resolution becomes accessible by mounting an additional polycapillary lens in front of an SDD detector. Quantitative confocal depth profiles (1D) are presented as well as the full separation of the front and the backside decorations with the help of fast 3D mappings of specific areas. Only through the use of these multidimensional modes can elemental information be assigned both to lateral and depth positions, making the analysis of such heterogeneous samples feasible.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1039/C6JA00220J
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“Determination of silicon in organic matrices with grazing-emission X-ray fluorescence spectrometry”. Claes M, van Dyck K, Deelstra H, Van Grieken R, Spectrochimica acta: part B : atomic spectroscopy 54, 1517 (1999). http://doi.org/10.1016/S0584-8547(99)00098-1
Abstract: The potential of a prototype grazing-emission X-ray fluorescence spectrometer for reliable analysis of sample solutions, obtained by pressurized microwave oven digestion of Si-spiked organic and biological materials, was investigated as part of an inter-laboratory study. The fact that this grazing-emission technique is based on the total reflection phenomenon and wavelength-dispersive detection, gives it the benefit to determine light elements in a sensitive way. Results of the determination of silicon in pork liver, cellulose, urine, serum, spinach, beer, mineral water and horsetail (dry plant extract) samples are presented. Some of the results are compared with those obtained with other analytical techniques. The study proved that determination of silicon traces in biological matrices represents an extremely difficult task, however, measurements of silicon are achieved with acceptable precision. The most important problems still arise when sample pre-treatment is needed prior to analysis. (C) 1999 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0584-8547(99)00098-1
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“Effects of Ag additive in low temperature CO detection with In2O3 based gas sensors”. Naberezhnyi D, Rumyantseva M, Filatova D, Batuk M, Hadermann J, Baranchikov A, Khmelevsky N, Aksenenko A, Konstantinova E, Gaskov A, Nanomaterials 8, 801 (2018). http://doi.org/10.3390/NANO8100801
Abstract: Nanocomposites In2O3/Ag obtained by ultraviolet (UV) photoreduction and impregnation methods were studied as materials for CO sensors operating in the temperature range 25-250 degrees C. Nanocrystalline In2O3 and In2O3/Ag nanocomposites were characterized by X-ray diffraction (XRD), single-point Brunauer-Emmet-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with energy dispersive X-ray (EDX) mapping. The active surface sites were investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy and thermo-programmed reduction with hydrogen (TPR-H-2) method. Sensor measurements in the presence of 15 ppm CO demonstrated that UV treatment leads to a complete loss of In2O3 sensor sensitivity, while In2O3/Ag-UV nanocomposite synthesized by UV photoreduction demonstrates an increased sensor signal to CO at T < 200 degrees C. The observed high sensor response of the In2O3/Ag-UV nanocomposite at room temperature may be due to the realization of an additional mechanism of CO oxidation with participation of surface hydroxyl groups associated via hydrogen bonds.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
DOI: 10.3390/NANO8100801
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“Efficient iron phosphide catalyst as a counter electrode in dye-sensitized solar cells”. Yildiz A, Chouki T, Atli A, Harb M, Verbruggen SW, Ninakanti R, Emin S, ACS applied energy materials 4, 10618 (2021). http://doi.org/10.1021/ACSAEM.1C01628
Abstract: Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Transition metal phosphides have been demonstrated as outstanding multifunctional catalysts in a broad range of energy conversion technologies. Here, we exploited different phases of iron phosphide as CEs in DSSCs with an I–/I3–-based electrolyte. Solvothermal synthesis using a triphenylphosphine precursor as a phosphorus source allows to grow a Fe2P phase at 300 °C and a FeP phase at 350 °C. The obtained iron phosphide catalysts were coated on fluorine-doped tin oxide substrates and heat-treated at 450 °C under an inert gas atmosphere. The solar-to-current conversion efficiency of the solar cells assembled with the Fe2P material reached 3.96 ± 0.06%, which is comparable to the device assembled with a platinum (Pt) CE. DFT calculations support the experimental observations and explain the fundamental origin behind the improved performance of Fe2P compared to FeP. These results indicate that the Fe2P catalyst exhibits excellent performance along with desired stability to be deployed as an efficient Pt-free alternative in DSSCs.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1021/ACSAEM.1C01628
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“Methods, fluxes and sources of gas phase alkyl nitrates in the coastal air”. Dirtu AC, Buczyńska AJ, Godoi AFL, Favoreto R, Bencs L, Potgieter-Vermaak SS, Godoi RHM, Van Grieken R, Van Vaeck L, Environmental monitoring and assessment 186, 6445 (2014). http://doi.org/10.1007/S10661-014-3866-7
Abstract: The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO2 levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
DOI: 10.1007/S10661-014-3866-7
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“On the impact of precipitation amount on the concentration of elements and ions in urban aerosol particles”. Deutsch F, Stranger M, Kaplinskii AE, Samek L, Joos P, Van Grieken R, Atmospheric and oceanic optics 16, 850 (2003)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“O vlijanii kolitsjestva osadkov na kontsentratsioe elementov i ionov v tsjastitsach gorodskogo aerozolja”. Deutsch F, Stranger M, Kaplinskii AE, Samek L, Joos P, Van Grieken R, Optika atmospheri i okeana 16, 927 (2003)
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Roadmap on structured waves”. Bliokh KY, Karimi E, Padgett MJ, Alonso MA, Dennis MR, Dudley A, Forbes A, Zahedpour S, Hancock SW, Milchberg HM, Rotter S, Nori F, Ozdemir SK, Bender N, Cao H, Corkum PB, Hernandez-Garcia C, Ren H, Kivshar Y, Silveirinha MG, Engheta N, Rauschenbeutel A, Schneeweiss P, Volz J, Leykam D, Smirnova DA, Rong K, Wang B, Hasman E, Picardi MF, Zayats AV, Rodriguez-Fortuno FJ, Yang C, Ren J, Khanikaev AB, Alu A, Brasselet E, Shats M, Verbeeck J, Schattschneider P, Sarenac D, Cory DG, Pushin DA, Birk M, Gorlach A, Kaminer I, Cardano F, Marrucci L, Krenn M, Marquardt F, Journal of optics 25, 103001 (2023). http://doi.org/10.1088/2040-8986/ACEA92
Abstract: Structured waves are ubiquitous for all areas of wave physics, both classical and quantum, where the wavefields are inhomogeneous and cannot be approximated by a single plane wave. Even the interference of two plane waves, or of a single inhomogeneous (evanescent) wave, provides a number of nontrivial phenomena and additional functionalities as compared to a single plane wave. Complex wavefields with inhomogeneities in the amplitude, phase, and polarization, including topological----- structures and singularities, underpin modern nanooptics and photonics, yet they are equally important, e.g. for quantum matter waves, acoustics, water waves, etc. Structured waves are crucial in optical and electron microscopy, wave propagation and scattering, imaging, communications, quantum optics, topological and non-Hermitian wave systems, quantum condensed-matter systems, optomechanics, plasmonics and metamaterials, optical and acoustic manipulation, and so forth. This Roadmap is written collectively by prominent researchers and aims to survey the role of structured waves in various areas of wave physics. Providing background, current research, and anticipating future developments, it will be of interest to a wide cross-disciplinary audience.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.1
Times cited: 7
DOI: 10.1088/2040-8986/ACEA92
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“Surfactant layers on gold nanorods”. Mosquera J, Wang D, Bals S, Liz-Marzan LM, Accounts of chemical research 56, 1204 (2023). http://doi.org/10.1021/ACS.ACCOUNTS.3C00101
Abstract: Gold nanorods (Au NRs) are an exceptionally promising tool in nanotechnology due to three key factors: (i) their strong interaction with electromagnetic radiation, stemming from their plasmonic nature, (ii) the ease with which the resonance frequency of their longitudinal plasmon mode can be tuned from the visible to the near-infrared region of the electromagnetic spect r u m based on their aspect ratio, and (iii) their simple and cost-effective preparation through seed-mediated chemical growth. In this synthetic method, surfactants play a critical role in controlling the size, shape, and colloidal stabi l i t y of Au NRs. For example, surfactants can stabilize specific crystallographic facets during the formation of Au NRs, leading to t h e formation of NRs with specific morphologies. The process of surfactant adsorption onto the NR surface may result in various assemblies of surfactant molecules, such as spherical micelles, elongated micelles, or bilayers. Again, the assembly mode is critical toward determining the further availabi l i t y of the Au NR surface to the surrounding medium. Despite its importance and a great deal of research effort, the interaction between Au NPs and surfactants remains insufficiently understood, because the assembly process is influenced by numerous factors, including the chemical nature of the surfactant, the surface morphology of Au NPs, and solution parameters. Therefore, gaining a more comprehensive understanding of these interactions is essential to unlock the full potential of the seed-mediated growth method and the applications of plasmonic NPs. A plethora of characterization techniques have been applied to reach such an understanding , but many open questions remain. In this Account, we review the current knowledge on the interactions between surfactants and Au NRs. We briefly introduce the state-of-the-art methods for synthesizing Au NRs and highlight the crucial role of cationic surfactants during this process. The self-assembly and organization of surfactants on the Au NR surface is then discussed to better understand their role in seed-mediated growth. Subsequently, we provide examples and elucidate how chemical additives can be used to modulate micellar assemblies, in turn allowing for a finer control over the growth of Au NRs, including chiral NRs. Next, we review the main experimental characterization and computational modeling techniques that have been applied to shed light on the arrangement of surfactants on Au NRs and summarize the advantages and disadvantages for each technique. The Account ends with a “Conclusions and Outlook” section, outlining promising future research directions and developments that we consider are sti l l required, mostly related to the application of electron microscopy in liquid and in 3D. Finally, we remark on the potential of exploiting machine learning techniques to predict synthetic routes for NPs with predefined structures and properties.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 18.3
Times cited: 8
DOI: 10.1021/ACS.ACCOUNTS.3C00101
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“Plasma‐driven<scp>CO2</scp>hydrogenation to<scp>CH3OH</scp>over<scp>Fe2O3</scp>/<scp>γ‐Al2O3</scp>catalyst”. Meng S, Wu L, Liu M, Cui Z, Chen Q, Li S, Yan J, Wang L, Wang X, Qian J, Guo H, Niu J, Bogaerts A, Yi Y, AIChE Journal 69, e18154 (2023). http://doi.org/10.1002/aic.18154
Abstract: We report a plasma‐assisted CO<sub>2</sub>hydrogenation to CH<sub>3</sub>OH over Fe<sub>2</sub>O<sub>3</sub>/γ‐Al<sub>2</sub>O<sub>3</sub>catalysts, achieving 12% CO<sub>2</sub>conversion and 58% CH<sub>3</sub>OH selectivity at a temperature of nearly 80°C atm pressure. We investigated the effect of various supports and loadings of the Fe‐based catalysts, as well as optimized reaction conditions. We characterized catalysts by X‐ray powder diffraction (XRD), hydrogen temperature programmed reduction (H<sub>2</sub>‐TPR), CO<sub>2</sub>and CO temperature programmed desorption (CO<sub>2</sub>/CO‐TPD), high‐resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM), x‐ray photoelectron spectroscopy (XPS), Mössbauer, and Fourier transform infrared<bold>(</bold>FTIR). The XPS results show that the enhanced CO<sub>2</sub>conversion and CH<sub>3</sub>OH selectivity are attributed to the chemisorbed oxygen species on Fe<sub>2</sub>O<sub>3</sub>/γ‐Al<sub>2</sub>O<sub>3</sub>. Furthermore, the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) and TPD results illustrate that the catalysts with stronger CO<sub>2</sub>adsorption capacity exhibit a higher reaction performance.<italic>In situ</italic>DRIFTS gain insight into the specific reaction pathways in the CO<sub>2</sub>/H<sub>2</sub>plasma. This study reveals the role of chemisorbed oxygen species as a key intermediate, and inspires to design highly efficient catalysts and expand the catalytic systems for CO<sub>2</sub>hydrogenation to CH<sub>3</sub>OH.
Keywords: A1 Journal Article; chemisorbed oxygen, CO2 hydrogenation, iron-based catalyst, methanol production, plasma catalysis; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 3.7
DOI: 10.1002/aic.18154
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“Competition between the Ni and Fe redox in the O3-NaNi1/3Fe1/3Mn1/3O2 cathode material for Na-ion batteries”. Shevchenko VA, Glazkova IS, Novichkov DA, Skvortsova I, V Sobolev A, Abakumov AM, Presniakov IA, Drozhzhin OA, V Antipov E, Chemistry of materials 35, 4015 (2023). http://doi.org/10.1021/ACS.CHEMMATER.3C00338
Abstract: Sodium-ion batteries are attracting great attention due to their low cost and abundance of sodium. The O3-type NaNi1/3Fe1/3Mn1/3O2 layered oxide material is a promising candidate for positive electrodes (cathodes) in Na-ion batteries. However, its stable electrochemical performance is restricted by the upper voltage limit of 4.0 V (vs Na/Na+), which allows for reversibly removing 0.5-0.55 Na+ per formula unit, corresponding to the capacity of 120-130 mAh.g(-1). Further reduction of sodium content inevitably accelerates capacity degradation, and this issue calls for a detailed study of the redox reactions that accompany the electrochemical (de)intercalation of a large amount of sodium. Here, we present operando and ex situ studies using powder X-ray diffraction and X-ray absorption spectroscopy combined with Fe-57 Mossbauer spectroscopy. Our approach reveals the sequence of the redox transitions that occur during the charge and discharge of O3-NaNi1/3Fe1/3Mn1/3O2. Our data show that in addition to nickel and iron cations oxidizing to M+4, a part of iron transforms into the “3 + delta” state owing to the fast electron exchange Fe3+ + Fe4+ <-> Fe4+ + Fe3+. This process freezes upon cooling the material to 35 K, producing Fe4+ cations, some of which occupy tetrahedral positions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 8.6
DOI: 10.1021/ACS.CHEMMATER.3C00338
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“Charged vacancy in graphene : interplay between Landau levels and atomic collapse resonances”. Wang J, Zhao W-S, Hu Y, Filho RNC, Peeters FM, Physical review B 109, 104103 (2024). http://doi.org/10.1103/PHYSREVB.109.104103
Abstract: The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive-energy region, but in the negative-energy region, they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number m are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same m, in this work anticrossing is found between the normal Landau level and the vacancy-induced level. The atomic collapse resonance hybridizes with the Landau levels. The charge at which the lowest Landau level m = -1, N = 1 crosses E = 0 increases with enhancing magnetic field. A Landau level scaling anomaly occurs when the charge is larger than the critical charge beta 0.6 and this critical charge is independent of the magnetic field.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.7
DOI: 10.1103/PHYSREVB.109.104103
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“Giant vortices in small mesoscopic disks : an approximate description”. Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 347 (2002). http://doi.org/10.1016/S0921-4534(01)01274-6
Abstract: We present an approximate description of the giant vortex state in a thin mesoscopic superconducting disk within the phenomenological Ginzburg-Landau approach. Analytical asymptotic expressions for the energies of the states with fixed vorticity are obtained when a small magnetic flux is accumulated in the disk. The spectrum of the lowest Landau levels of such a disk is also discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
DOI: 10.1016/S0921-4534(01)01274-6
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“Magnetic coupling between mesoscopic superconducting rings”. Baelus BJ, Yampolskii SV, Peeters FM, Physica: C : superconductivity 369, 366 (2002). http://doi.org/10.1016/S0921-4534(01)01278-3
Abstract: Using the nonlinear Ginzburg-Landau theory we investigated the dependence of the magnetic coupling between two concentric mesoscopic superconducting rings on their thickness. The size of this magnetic coupling increases with the thickness of the rings. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.404
Times cited: 1
DOI: 10.1016/S0921-4534(01)01278-3
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