|
“Semihard iron-based permanent-magnet materials”. Yin L, Juneja R, Lindsay L, Pandey T, Parker DS, Physical Review Applied 15, 024012 (2021). http://doi.org/10.1103/PHYSREVAPPLIED.15.024012
Abstract: Permanent magnets generally require a favorable, but difficult-to-achieve combination of high magnetization, Curie point, and magnetic anisotropy. Thus there have been few, if any, viable permanent magnets developed since the 1982 discovery of Nd2Fe14B [M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and S. Hirosawa, J. Appl. Phys. 57, 4094 (1985)]. Here we point out, both by direct first-principles calculations on the iron carbides and silicides Fe5C2, Fe5SiC, and Fe7C3 as well as a discussion of recent experimental findings, that there are numerous rare-earth-free iron-rich potential permanent-magnet materials with sufficient intrinsic magnetic properties to reasonably achieve room-temperature energy products of 20-25 MG Oe. This is substantially better than the performance of the best available rare-earth-free magnets based on ferrite, as well as shape-anisotropy-employing alnico. These magnets could plausibly fill, at low cost, the present performance “gap” [J. M. D. Coey, Scr. Mater. 67, 524 (2012)] between the best rare-earth-free magnets and rare-earth magnets such as Nd2Fe14B and Sm-Co.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 4.808
DOI: 10.1103/PHYSREVAPPLIED.15.024012
|
|
|
“Seeded growth combined with cation exchange for the synthesis of anisotropic Cu2-xS/ZnS, Cu2-xS, and CuInS2 nanorods”. Xia C, Pedrazo-Tardajos A, Wang D, Meeldijk JD, Gerritsen HC, Bals S, de Donega CM, Chemistry of materials 33, 102 (2021). http://doi.org/10.1021/ACS.CHEMMATER.0C02817
Abstract: Colloidal copper(I) sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu2-xS NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu2-xS/ZnS heteronanorods. The Janus-type Cu2-xS/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu2-xS seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors. The Cu2-xS seed NCs undergo rapid aggregation and coalescence in the first few seconds after the injection, forming larger NCs that act as the effective seeds for heteronucleation and growth of ZnS. The ZnS heteronucleation occurs on a single (100) facet of the Cu2-xS seed NCs and is followed by fast anisotropic growth along a direction that is perpendicular to the c-axis, thus leading to Cu2-xS/ZnS Janus-type heteronanorods with a sharp heterointerface. Interestingly, the high-chalcocite crystal structure of the injected Cu2-xS seed NCs is preserved in the Cu2-xS segments of the heteronanorods because of the highthermodynamic stability of this Cu2-xS phase. The Cu2-xS/ZnS heteronanorods are subsequently converted into single-component Cu2-xS and CuInS2 nanorods by postsynthetic topotactic cation exchange. This work expands the possibilities for the rational synthesis of colloidal multicomponent heteronanorods by allowing the design principles of postsynthetic heteroepitaxial seeded growth and nanoscale cation exchange to be combined, yielding access to a plethora of multicomponent heteronanorods with diameters in the quantum confinement regime.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 10
DOI: 10.1021/ACS.CHEMMATER.0C02817
|
|
|
“Confinement and edge effects on atomic collapse in graphene nanoribbons”. Wang J, Van Pottelberge R, Jacobs A, Van Duppen B, Peeters FM, Physical Review B 103, 035426 (2021). http://doi.org/10.1103/PHYSREVB.103.035426
Abstract: Atomic collapse in graphene nanoribbons behaves in a fundamentally different way as compared to monolayer graphene due to the presence of multiple energy bands and the effect of edges. For armchair nanoribbons we find that bound states gradually transform into atomic collapse states with increasing impurity charge. This is very different in zigzag nanoribbons where multiple quasi-one-dimensional bound states are found that originates from the zero-energy zigzag edge states. They are a consequence of the flat band and the electron distribution of these bound states exhibits two peaks. The lowest-energy edge state transforms from a bound state into an atomic collapse resonance and shows a distinct relocalization from the edge to the impurity position with increasing impurity charge.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PHYSREVB.103.035426
|
|
|
“Halide perovskite-lead chalcohalide nanocrystal heterostructures”. Imran M, Peng L, Pianetti A, Pinchetti V, Ramade J, Zito J, Di Stasio F, Buha J, Toso S, Song J, Infante I, Bals S, Brovelli S, Manna L, Journal Of The American Chemical Society 143, 1435 (2021). http://doi.org/10.1021/JACS.0C10916
Abstract: We report the synthesis of colloidal CsPbX3-Pb4S3Br2 (X = Cl, Br, I) nanocrystal heterostructures, providing an example of a sharp and atomically resolved epitaxial interface between a metal halide perovskite and a non-perovskite lattice. The CsPbBr3-Pb4S3Br2 nanocrystals are prepared by a two-step direct synthesis using preformed subnanometer CsPbBr3 clusters. Density functional theory calculations indicate the creation of a quasi-type II alignment at the heterointerface as well as the formation of localized trap states, promoting ultrafast separation of photogenerated excitons and carrier trapping, as confirmed by spectroscopic experiments. Postsynthesis reaction with either Cl- or I- ions delivers the corresponding CsPbCI3-Pb4S3Br2 and CsPbI3-Pb4S3Br2 heterostructures, thus enabling anion exchange only in the perovskite domain. An increased structural rigidity is conferred to the perovskite lattice when it is interfaced with the chalcohalide lattice. This is attested by the improved stability of the metastable gamma phase (or “black” phase) of CsPbI3 in the CsPbI3-Pb4S3Br2 heterostructure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 13.858
Times cited: 54
DOI: 10.1021/JACS.0C10916
|
|
|
“Two-dimensional oxygen functionalized honeycomb and zigzag dumbbell silicene with robust Dirac cones”. Chen X, Li L, Peeters FM, Sanyal B, New Journal Of Physics 23, 023007 (2021). http://doi.org/10.1088/1367-2630/ABDB6E
Abstract: Dumbbell-like structures are recently found to be energetically favored in group IV two-dimensional (2D) materials, exhibiting rich physics and many interesting properties. In this paper, using first-principles calculations, we have investigated the oxidized form of the hexagonal honeycomb (ODB-h) and zigzag dumbbell silicene (ODB-z). We confirm that both oxidization processes are energetically favorable, and their phonon spectra further demonstrate the dynamic stability. Contrary to the pristine dumbbell silicene structures (PDB-h and PDB-z silicene), these oxidized products ODB-h and ODB-z silicene are both semimetals with Dirac cones at the Fermi level. The Dirac cones of ODB-h and ODB-z silicene are at the K point and between Y and Gamma points respectively, possessing high Fermi velocities of 3.1 x 10(5) m s(-1) (ODB-h) and 2.9-3.4 x 10(5) m s(-1) (ODB-z). The origin of the Dirac cones is further explained by tight-binding models. The semimetallic properties of ODB-h and ODB-z are sensitive to compression due to the self-absorption effect, but quite robust against the tensile strain. These outstanding properties make oxidized dumbbell silicene a promising material for quantum computing and high-speed electronic devices.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.786
Times cited: 2
DOI: 10.1088/1367-2630/ABDB6E
|
|
|
“Positive and negative streamer propagation in volume dielectric barrier discharges with planar and porous electrodes”. Zhang Q‐Z, Zhang L, Yang D‐Z, Schulze J, Wang Y‐N, Bogaerts A, Plasma Processes And Polymers 18, 2000234 (2021). http://doi.org/10.1002/ppap.202000234
Abstract: The spatiotemporal dynamics of volume and surface positive and negative streamers in a pintoplate volume dielectric barrier discharge is investigated in this study. The discharge characteristics are found to be completely different for positive and negative streamers. First, the spatial propagation of a positive streamer is found to rely on electron avalanches caused by photo-electrons in front of the streamer head, whereas this is not the case for negative streamers. Second, our simulations reveal an interesting phenomenon of floating positive surface discharges, which develop when a positive streamer reaches a dielectric wall and which explain the experimentally observed branching characteristics. Third, we report for the first time, the interactions between a positive streamer and dielectric pores, in which both the pore diameter and depth affect the evolution of a positive streamer.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.846
DOI: 10.1002/ppap.202000234
|
|
|
“First-principles study of defects at Σ3 grain boundaries in CuGaSe2”. Saniz R, Bekaert J, Partoens B, Lamoen D, Solid State Communications , 114263 (2021). http://doi.org/10.1016/j.ssc.2021.114263
Abstract: We present a first-principles computational study of cation–Se 3 (112) grain boundaries in CuGaSe. We discuss the structure of these grain boundaries, as well as the effect of native defects and Na impurities on their electronic properties. The formation energies show that the defects will tend to form preferentially at the grain boundaries, rather than in the grain interiors. We find that in Ga-rich growth conditions Cu vacancies as well as Ga at Cu and Cu at Ga antisites are mainly responsible for having the equilibrium Fermi level pinned toward the middle of the gap, resulting in carrier depletion. The Na at Cu impurity in its +1 charge state contributes to this. In Ga-poor growth conditions, on the other hand, the formation energies of Cu vacancies and Ga at Cu antisites are comparatively too high for any significant influence on carrier density or on the equilibrium Fermi level position. Thus, under these conditions, the Cu at Ga antisites give rise to a -type grain boundary. Also, their formation energy is lower than the formation energy of Na at Cu impurities. Thus, the latter will fail to act as a hole barrier preventing recombination at the grain boundary, in contrast to what occurs in CuInSe grain boundaries. We also discuss the effect of the defects on the electronic properties of bulk CuGaSe, which we assume reflect the properties of the grain interiors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 1.554
Times cited: 1
DOI: 10.1016/j.ssc.2021.114263
|
|
|
“The design of magneto-plasmonic nanostructures formed by magnetic Prussian Blue-type nanocrystals decorated with Au nanoparticles”. Sanchis-Gual R, Susic I, Torres-Cavanillas R, Arenas-Esteban D, Bals S, Mallah T, Coronado-Puchau M, Coronado E, Chemical Communications 57, 1903 (2021). http://doi.org/10.1039/D0CC08034A
Abstract: We have developed a general protocol for the preparation of hybrid nanostructures formed by nanoparticles (NPs) of molecule-based magnets based on Prussian Blue Analogues (PBAs) decorated with plasmonic Au NPs of different shapes. By adjusting the pH, Au NPs can be attached preferentially along the edges of the PBA or randomly on the surface. The protocol allows tuning the plasmonic properties of the hybrids in the whole visible spectrum.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.319
Times cited: 5
DOI: 10.1039/D0CC08034A
|
|
|
“Oxidation of Innate Immune Checkpoint CD47 on Cancer Cells with Non-Thermal Plasma”. Lin A, Razzokov J, Verswyvel H, Privat-Maldonado A, De Backer J, Yusupov M, Cardenas De La Hoz E, Ponsaerts P, Smits E, Bogaerts A, Cancers 13, 579 (2021). http://doi.org/10.3390/cancers13030579
Abstract: Non-thermal plasma (NTP) therapy has been emerging as a promising cancer treatment strategy, and recently, its ability to locally induce immunogenic cancer cell death is being unraveled. We hypothesized that the chemical species produced by NTP reduce immunosuppressive surface proteins and checkpoints that are overexpressed on cancerous cells. Here, 3D in vitro tumor models, an in vivo mouse model, and molecular dynamics simulations are used to investigate the effect of NTP on CD47, a key innate immune checkpoint. CD47 is immediately modulated after NTP treatment and simulations reveal the potential oxidized salt-bridges responsible for conformational changes. Umbrella sampling simulations of CD47 with its receptor, signal-regulatory protein alpha (SIRPα), demonstrate that the induced-conformational changes reduce its binding affinity. Taken together, this work provides new insight into fundamental, chemical NTP-cancer cell interaction mechanisms and a previously overlooked advantage of present NTP cancer therapy: reducing immunosuppressive signals on the surface of cancer cells.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Laboratory for Experimental Hematology (LEH); Center for Oncological Research (CORE)
DOI: 10.3390/cancers13030579
|
|
|
“Electrochemical and spectroelectrochemical studies of tert-butyl-substituted aluminum phthalocyanine”. Moiseeva EO, Trashin S, Korostei YS, Khan SU, Kosov AD, De Wael K, Dubinina TV, Tomilova LG, Polyhedron 200, 115136 (2021). http://doi.org/10.1016/J.POLY.2021.115136
Abstract: Tetra-tert-butylphthalocyanine aluminum (III) chloride was studied by voltammetric and potential-resolved spectroelectrochemical methods in a non-coordinating solvent o-dichlorobenzene. Five redox transitions were found including two oxidation waves at 0.18 and 0.90 V and three reduction waves at −1.28, −1.65, and −2.63 V vs. Fc+/Fc. Electrochemical reversibility of the first oxidation and reduction processes was assessed by using the diagnostic criteria of cyclic voltammetry. First comprehensive spectroelectrochemical characterization of oxidation of the aluminum phthalocyanine is reported. Moreover, potential-resolved spectroelectrochemical titration revealed strong influence of aggregation on the UV–vis spectra and the half-wave potentials of the first oxidation transition and disclosed the presence of the partially oxidized complex in the initial solution, which noticeably affected the spectrum of the neutral form.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.926
DOI: 10.1016/J.POLY.2021.115136
|
|
|
“Derivatization of amphetamine to allow its electrochemical detection in illicit drug seizures”. Parrilla M, Montiel FN, Van Durme F, De Wael K, Sensors And Actuators B-Chemical 337, 129819 (2021). http://doi.org/10.1016/J.SNB.2021.129819
Abstract: Amphetamine (AMP) is posing critical issues in our society being one of the most encountered drugs-of-abuse in the current illicit market. The continuous drug production in Europe urges the development of new tools for the rapid on-site determination of illicit drugs such as AMP. However, the direct electrochemical detection of AMP is a challenge because the molecule is non-electroactive at the potential window of conventional graphite SPEs. For this reason, a derivatization step is needed to convert the primary amine into an electroactive oxidizable group. Herein, the rapid electrochemical detection of AMP in seized samples based on the derivatization by 1,2-naphthoquinone-4-sulfonate (NQS) is presented by using square wave voltammetry (SWV) at graphite screen-printed electrodes (SPEs). First, a detailed optimization of the key parameters and the analytical performance is provided. The method showed a sensitivity of 7.9 µA mM-1 within a linear range from 50 to 500 µM, a limit of detection of 22.2 µM, and excellent reproducibility (RSD = 4.3%, n = 5 at 500 µM). Subsequently, the effect of NQS on common cutting agents for the selective detection of AMP is addressed. The comparison of the method with drugs-of-abuse containing secondary and tertiary amines confirms the selectivity of the method. Finally, the concept is applied to quantify AMP in 20 seized samples provided by forensic laboratories, exhibiting an accuracy of 97.3 ± 10.5%. Overall, the fast analysis of samples with the electrochemical profiling of derivatized AMP exhibits a straightforward on-site screening aiming to facilitate the tasks of law enforcement agents in the field.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 5.401
DOI: 10.1016/J.SNB.2021.129819
|
|
|
“Electrochemistry of intact versus degraded cephalosporin antibiotics facilitated by LC–MS analysis”. Sleegers N, van Nuijs ALN, van den Berg M, De Wael K, Analytical Chemistry 93, 2394 (2021). http://doi.org/10.1021/ACS.ANALCHEM.0C04286
Abstract: The electrochemical detection of cephalosporins is a promising approach for the monitoring of cephalosporin levels in process waters. However, this class of antibiotics, like penicillins, is composed of chemically active molecules and susceptible to hydrolysis and aminolysis of the four membered β-lactam ring present. In order to develop a smart monitoring strategy for cephalosporins, the influence of degradation (hydrolysis and aminolysis) on the electrochemical fingerprint has to be taken into account. Therefore, an investigation was carried out to understand the changes of the voltammetric fingerprints upon acidic and alkaline degradation. Changes in fingerprints were correlated to the degradation pathways through the combination of square wave voltammetry and liquid chromatography quadrupole time-of-flight analysis. The characteristic electrochemical signals of the β-lactam ring disappeared upon hydrolysis. Additional oxidation signals that appeared after degradation were elucidated and linked to different degradation products, and therefore, enrich the voltammetric fingerprints with information of the state of the cephalosporins. The applicability of the electrochemical monitoring system was explored by the analysis of the intact and degraded industrial process waters containing the key intermediate 7-aminodeacetoxycephalosporanic acid (7-ADCA). Clearly, the intact process samples exhibited the expected core signals of 7-ADCA and could be quantified, while the degraded samples only showed the newly formed degradation products.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 6.32
DOI: 10.1021/ACS.ANALCHEM.0C04286
|
|
|
“Efficient Ab initio modeling of dielectric screening in 2D van der Waals materials : including phonons, substrates, and doping”. Gjerding MN, Cavalcante LSR, Chaves A, Thygesen KS, Journal Of Physical Chemistry C 124, 11609 (2020). http://doi.org/10.1021/ACS.JPCC.0C01635
Abstract: The quantum electrostatic heterostructure (QEH) model allows for efficient computation of the dielectric screening properties of layered van der Waals (vdW)-bonded heterostructures in terms of the dielectric functions of the individual two-dimensional (2D) layers. Here, we extend the QEH model by including (1) contributions to the dielectric function from infrared active phonons in the 2D layers, (2) screening from homogeneous bulk substrates, and (3) intraband screening from free carriers in doped 2D semiconductor layers. We demonstrate the potential of the extended QEH model by calculating the dispersion of coupled phonons in multilayer stacks of hexagonal boron-nitride (hBN), the strong hybridization of plasmons and optical phonons in graphene/hBN heterostructures, the effect of substrate screening on the exciton series of monolayer MoS2, and the properties of hyperbolic plasmons in a doped phosphorene sheet. The new QEH code is distributed as a Python package with a simple command line interface and a comprehensive library of dielectric building blocks for the most common 2D materials, providing an efficient open platform for dielectric modeling of realistic vdW heterostructures.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 3.7
DOI: 10.1021/ACS.JPCC.0C01635
|
|
|
“Unlocking the genomic potential of aerobes and phototrophs for the production of nutritious and palatable microbial food without arable land or fossil fuels”. Alloul A, Spanoghe J, Machado D, Vlaeminck SE, Microbial biotechnology 15, 6 (2022). http://doi.org/10.1111/1751-7915.13747
Abstract: The increasing world population and living standards urgently necessitate the transition towards a sustainable food system. One solution is microbial protein, i.e. using microbial biomass as alternative protein source for human nutrition, particularly based on renewable electron and carbon sources that do not require arable land. Upcoming green electrification and carbon capture initiatives enable this, yielding new routes to H2, CO2 and CO2-derived compounds like methane, methanol, formic- and acetic acid. Aerobic hydrogenotrophs, methylotrophs, acetotrophs and microalgae are the usual suspects for nutritious and palatable biomass production on these compounds. Interestingly, these compounds are largely un(der)explored for purple non-sulfur bacteria, even though these microbes may be suitable for growing aerobically and phototrophically on these substrates. Currently, selecting the best strains, metabolisms and cultivation conditions for nutritious and palatable microbial food mainly starts from empirical growth experiments, and mostly does not stretch beyond bulk protein. We propose a more target-driven and efficient approach starting from the genome-embedded potential to tuning towards, for instance, essential amino- and fatty acids, vitamins, taste,... Genome-scale metabolic models combined with flux balance analysis will facilitate this, narrowing down experimental variations and enabling to get the most out of the 'best' combinations of strain and electron and carbon sources.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 5.7
DOI: 10.1111/1751-7915.13747
|
|
|
“Effect of chemical modification on electronic transport properties of carbyne”. Berdiyorov GR, Khalilov U, Hamoudi H, Neyts EC, Journal Of Computational Electronics (2021). http://doi.org/10.1007/s10825-020-01639-7
Abstract: Using density functional theory in combination with the Green’s functional formalism, we study the effect of surface functionalization on the electronic transport properties of 1D carbon allotrope—carbyne. We found that both hydrogenation and fluorination result in structural changes and semiconducting to metallic transition. Consequently, the current in the functionalization systems increases significantly due to strong delocalization of electronic states along the carbon chain. We also study the electronic transport in partially hydrogenated carbyne and interface structures consisting of pristine and functionalized carbyne. In the latter case, current rectification is obtained in the system with rectification ratio up to 50%. These findings can be useful for developing carbyne-based structures with tunable electronic transport properties.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 1.526
DOI: 10.1007/s10825-020-01639-7
|
|
|
“MoSi₂N₄, single-layer : a novel two-dimensional material with outstanding mechanical, thermal, electronic and optical properties”. Bafekry A, Faraji M, Hoat DM, Shahrokhi M, Fadlallah MM, Shojaei F, Feghhi SAH, Ghergherehchi M, Gogova D, Journal Of Physics D-Applied Physics 54, 155303 (2021). http://doi.org/10.1088/1361-6463/ABDB6B
Abstract: Very recently, the 2D form of MoSi2N4 has been successfully fabricated (Hong et al 2020 Science 369 670). Motivated by these recent experimental results, we investigate the structural, mechanical, thermal, electronic and optical properties of the MoSi2N4 monolayer. The mechanical study confirms the stability of the MoSi2N4 monolayer. The Young's modulus decreases by similar to 30%, while the Poisson's ratio increases by similar to 30% compared to the corresponding values of graphene. In addition, the MoSi2N4 monolayer's work function is very similar to that of phosphorene and MoS2 monolayers. The electronic structure shows that the MoSi2N4 monolayer is an indirect semiconductor with a band gaps of 1.79 (2.35) eV using the GGA (HSE06) functional. The thermoelectric performance of the MoSi2N4 monolayer has been revealed and a figure of merit slightly larger than unity at high temperatures is calculated. The optical analysis shows that the first absorption peak for in-plane polarization is located in the visible range of the spectrum, therefore, the MoSi2N4 monolayer is a promising candidate for advanced optoelectronic nanodevices. In summary, the fascinating MoSi2N4 monoloayer is a promising 2D material for many applications due to its unique physical properties.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.588
DOI: 10.1088/1361-6463/ABDB6B
|
|
|
“Hydration effects and negative dielectric constant of nano-confined water between cation intercalated MXenes”. Jalali H, Khoeini F, Peeters FM, Neek-Amal M, Nanoscale 13, 922 (2021). http://doi.org/10.1039/D0NR03953E
Abstract: Using electrochemical methods a profound enhancement of the capacitance of electric double layer capacitor electrodes was reported when water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets [A. Sugahara et al., Nat. Commun., 2019, 10, 850]. We study the effects of hydration on the dielectric properties of nanoconfined water and supercapacitance properties of the cation intercalated MXene. A model for the electric double layer capacitor is constructed where water molecules are strongly confined in two-dimensional slits of MXene. We report an abnormal dielectric constant and polarization of nano-confined water between MXene layers. We found that by decreasing the ionic radius of the intercalated cations and in a critical hydration shell radius the capacitance of the system increases significantly (similar or equal to 200 F g(-1)) which can be interpreted as a negative permittivity. This study builds a bridge between the fundamental understanding of the dielectric properties of nanoconfined water and the capability of using MXene films for supercapacitor technology, and in doing so provides a solid theoretical support for recent experiments.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 7.367
Times cited: 7
DOI: 10.1039/D0NR03953E
|
|
|
“Photoresistive gas sensor based on nanocrystalline ZnO sensitized with colloidal perovskite CsPbBr3 nanocrystals”. Chizhov As, Rumyantseva Mn, Drozdov Ka, Krylov Iv, Batuk M, Hadermann J, Filatova Dg, Khmelevsky No, Kozlovsky Vf, Maltseva Ln, Gaskov Am, Sensors And Actuators B-Chemical 329, 129035 (2021). http://doi.org/10.1016/j.snb.2020.129035
Abstract: The development of sensor materials of which gas sensitivity activates under light illumination is of great importance for the design of portable gas analyzers with low power consumption. In the present work a ZnO/CsPbBr3 nanocomposite based on nanocrystalline ZnO and colloidal cubic-shaped perovskite CsPbBr3 nanocrystals (NCs) capped by oleic acide and oleylamine was synthesized. The individual materials and obtained nanocomposite are characterized by x-ray diffraction, low-temperature nitrogen adsorption, x-ray photoelectron spectroscopy, high angle annular dark field scanning transmission electron microscopy with energy-dispersive Xray spectroscopy mapping and UV-vis absorption spectroscopy. The spectral dependence of the photoconductivity of the ZnO/CsPbBr3 nanocomposite reveals a well-defined peak that strongly correlates with the its optical absorption spectrum. The nanocomposite ZnO/CsPbBr3 shows enhanced photoresponse under visible light illumination (lambda(max) = 470 nm, 8 mW/cm(2)) in air, oxygen and argone, compared with pure nanocrystalline ZnO. Under periodic illumination in the temperature range of 25-100 degrees C, the ZnO/CsPbBr3 nanocomposite shows a sensor response to 0.5-3.0 ppm NO2, unlike pure nanocrystalline ZnO matrix, which demonstrates sensor sensitivity to NO2 under the same conditions above 100 degrees C. The effects of humidity on the sensor signal and photoresponse are also discussed.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.401
DOI: 10.1016/j.snb.2020.129035
|
|
|
“Misfit phase (BiSe)1.10NbSe2 as the origin of superconductivity in niobium-doped bismuth selenide”. Kamminga ME, Batuk M, Hadermann J, Clarke SJ, Communications Materials 1, 82 (2020). http://doi.org/10.1038/s43246-020-00085-z
Abstract: Topological superconductivity is of great contemporary interest and has been proposed in doped Bi<sub>2</sub>Se<sub>3</sub>, in which electron-donating atoms such as Cu, Sr or Nb have been intercalated into the Bi<sub>2</sub>Se<sub>3</sub>structure. For Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>, with<italic>T</italic><sub>c</sub> ~ 3 K, it is assumed in the literature that Nb is inserted in the van der Waals gap. However, in this work an alternative origin for the superconductivity in Nb-doped Bi<sub>2</sub>Se<sub>3</sub>is established. In contrast to previous reports, it is deduced that Nb intercalation in Bi<sub>2</sub>Se<sub>3</sub>does not take place. Instead, the superconducting behaviour in samples of nominal composition Nb<sub><italic>x</italic></sub>Bi<sub>2</sub>Se<sub>3</sub>results from the (BiSe)<sub>1.10</sub>NbSe<sub>2</sub>misfit phase that is present in the sample as an impurity phase for small<italic>x</italic>(0.01 ≤ <italic>x</italic> ≤ 0.10) and as a main phase for large<italic>x</italic>(<italic>x</italic> = 0.50). The structure of this misfit phase is studied in detail using a combination of X-ray diffraction and transmission electron microscopy techniques.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1038/s43246-020-00085-z
|
|
|
“Local conversion of redox inactive molecules into redox active ones : a formaldehyde based strategy for the electrochemical detection of illicit drugs containing primary and secondary amines”. Schram J, Thiruvottriyur Shanmugam S, Sleegers N, Florea A, Samyn N, van Nuijs ALN, De Wael K, Electrochimica Acta 367, 137515 (2021). http://doi.org/10.1016/J.ELECTACTA.2020.137515
Abstract: Electrochemical techniques have evidenced to be highly suitable for the development of portable, rapid and accurate screening methods for the detection of illicit drugs in seized samples. However, the redox inactivity of primary amines, one of the most common functional groups of illicit drugs, masks voltammetric detection in aqueous environment at carbon electrodes and, therefore, leads to false negative results if only these primary amines are present in the structures. This work explores the feasibility of a derivatisation approach that introduces formaldehyde in the measuring conditions in order to achieve methylation, via an Eschweiler-Clarke mechanism, of illicit drugs containing primary and secondary amines, using amphetamine (AMP) and methamphetamine (MET) as model molecules. As a result the electrochemical fingerprint is enriched and thereby the detectability enhanced. A combination of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOFMS) and square-wave voltammetric (SWV) measurements is employed to identify reaction products and link them to the observed redox peaks. Although an alkaline environment (pH 12.0) proved to increase the reaction yield, a richer electrochemical fingerprint (EF) is obtained in neutral conditions (pH 7.0). Similarly, the addition of formate improved the reaction conversion but reduced the EF by eliminating a redox peak that is attributed to side products formed in the absence of formate. To illustrate the applicability, the derivatisation strategy is applied to several prominent illicit drugs containing primary and secondary amines to demonstrate its EF enriching capabilities. Finally, real street samples from forensic seizures are analysed. Overall, this strategy unlocks the detectability of the hitherto undetectable AMP and other drugs only containing primary amines, while strongly facilitating the identification of MET and analogues. These findings are not limited to illicit drugs, the insights can ultimately be applied to other target molecules containing similar functional groups. (C) 2020 Published by Elsevier Ltd.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 4.798
DOI: 10.1016/J.ELECTACTA.2020.137515
|
|
|
“Morphological and elemental characterization of leaf-deposited particulate matter from different source types : a microscopic investigation”. Castanheiro A, Wuyts K, Hofman J, Nuyts G, De Wael K, Samson R, Environmental Science And Pollution Research 28, 25716 (2021). http://doi.org/10.1007/S11356-021-12369-Z
Abstract: Particulate matter (PM) deposition on urban green enables the collection of particulate pollution from a diversity of contexts, and insight into the physico-chemical profiles of PM is key for identifying main polluting sources. This study reports on the morphological and elemental characterization of PM2-10 deposited on ivy leaves from five different environments (forest, rural, roadside, train, industry) in the region of Antwerp, Belgium. Ca. 40,000 leaf-deposited particles were thoroughly investigated by particle-based analysis using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX) and their physico-chemical characteristics were explored for PM source apportionment purposes. The size distribution of all deposited particles was biased towards small-sized PM, with 32% of the particles smaller than 2.5 mu m (PM2.5) and median diameters of 2.80-3.09 mu m. The source type influenced both the particles' size and morphology (aspect ratio and shape), with roadside particles being overall the smallest in size and the most spherical. While forest and rural elemental profiles were associated with natural PM, the industry particles revealed the highest anthropogenic metal input. PM2-10 profiles for roadside and train sites were rather comparable and only distinguishable when evaluating the fine (2-2.5 mu m) and coarse (2.5-10 mu m) PM fractions separately, which enabled the identification of a larger contribution of combustion-derived particles (small, circular, Fe-enriched) at the roadside compared to the train. Random forest prediction model classified the source type correctly for 61-85% of the leaf-deposited PM. The still modest classification accuracy denotes the influence of regional background PM and demands for additional fingerprinting techniques to facilitate source apportionment. Nonetheless, the obtained results demonstrate the utility of leaf particle-based analysis to fingerprint and pinpoint source-specific PM, particularly when considering both the composition and size of leaf-deposited particles.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.741
DOI: 10.1007/S11356-021-12369-Z
|
|
|
“Critical behavior of the ferromagnets CrI₃, CrBr₃, and CrGeTe₃, and the antiferromagnet FeCl₂, : a detailed first-principles study”. Tiwari S, Van de Put ML, Sorée B, Vandenberghe WG, Physical Review B 103, 014432 (2021). http://doi.org/10.1103/PHYSREVB.103.014432
Abstract: We calculate the Curie temperature of layered ferromagnets, chromium tri-iodide (CrI3), chromium tri-bromide (CrBr3), chromium germanium tri-telluride (CrGeTe3), and the Ned temperature of a layered antiferromagnet iron di-chloride (FeCl2), using first-principles density functional theory calculations and Monte Carlo simulations. We develop a computational method to model the magnetic interactions in layered magnetic materials and calculate their critical temperature. We provide a unified method to obtain the magnetic exchange parameters (J) for an effective Heisenberg Hamiltonian from first principles, taking into account both the magnetic ansiotropy as well as the out-of-plane interactions. We obtain the magnetic phase change behavior, in particular the critical temperature, from the susceptibility and the specific-heat, calculated using the three-dimensional Monte Carlo (METROPOLIS) algorithm. The calculated Curie temperatures for ferromagnetic materials (CrI3, CrBr3, and CrGeTe3), match well with experimental values. We show that the interlayer interaction in bulk CrI3 with R (3) over bar stacking is significantly stronger than the C2/m stacking, in line with experimental observations. We show that the strong interlayer interaction in R (3) over bar CrI3 results in a competition between the in-plane and the out-of-plane magnetic easy axes. Finally, we calculate the Ned temperature of FeCl2 to be 47 +/- 8 K and show that the magnetic phase transition in FeCl2 occurs in two steps with a high-temperature intralayer ferromagnetic phase transition and a low-temperature interlayer antiferromagnetic phase transition.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
DOI: 10.1103/PHYSREVB.103.014432
|
|
|
“Mn₂O₃, oxide with bixbyite structure for the electrochemical oxygen reduction reaction in alkaline media : highly active if properly manipulated”. Ryabova AS, Istomin SY, Dosaev KA, Bonnefont A, Hadermann J, Arkharova NA, Orekhov AS, Sena RP, Saveleva VA, Kerangueven G, Antipov E V, Savinova ER, Tsirlina GA, Electrochimica Acta 367, 137378 (2021). http://doi.org/10.1016/J.ELECTACTA.2020.137378
Abstract: We consider compositional and structural factors which can affect the activity of bixbyite alpha-Mn2O3 towards the oxygen reduction reaction (ORR) and the stability of this oxide in alkaline solution. We compare electrochemistry of undoped, Fe and Al-doped alpha-Mn2O3 with bixbyite structure and braunite Mn7SiO12 having bixbyite-related crystal structure, using the rotating disk electrode (RDE), the rotating ring-disk electrode (RRDE), and cyclic voltammetry (CV) techniques. All manganese oxides under study are stable in the potential range between the ORR onset and ca. 0.7 V vs. Reversible Hydrogen Electrode (RHE). It is found that any changes introduced in the bixbyite structure and/or composition of alpha-Mn2O3 lead to an activity drop in both the oxygen reduction and hydrogen peroxide reactions in this potential interval. For the hydrogen peroxide reduction reaction these modifications also result in a change in the nature of the rate-determining step. The obtained results confirm that due to its unique crystalline structure undoped alpha-Mn2O3 is the most ORR active (among currently available) Mn oxide catalyst and favor the assumption of the key role of the (111) surface of alpha-Mn2O3 in the very high activity of this material towards the ORR. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.798
DOI: 10.1016/J.ELECTACTA.2020.137378
|
|
|
“Impact of ordering on the reactivity of mixed crystals of topological insulators with anion substitution: Bi₂SeTe₂, and Sb₂SeTe₂”. Volykhov AA, Frolov AS, Neudachina VS, Vladimirova NV, Gerber E, Callaert C, Hadermann J, Khmelevsky NO, Knop-Gericke A, Sanchez-Barriga J, Yashina LV, Applied Surface Science 541, 148490 (2021). http://doi.org/10.1016/J.APSUSC.2020.148490
Abstract: Three-dimensional topological insulators are exotic materials with unique properties. Tetradymite type binary chalcogenides of bismuth and antimony, as well as their mixed crystals, belong to prototypical TIs. Potential device applications of these materials require in-depth knowledge of their stability in the ambient atmosphere and other media maintained during their processing. Here we investigated the reactivity of mixed crystals with anion substitution, Bi-2(Se1-xTex)(3) and Sb2(Se1-xTex)(3), towards molecular oxygen using both in situ and ex situ X-ray photoelectron spectroscopy. The results indicate that, in contrast to cation substitution, partial substitution of tellurium by selenium atoms leads to anomalously high surface reactivity, which even exceeds that of the most reactive binary constituent. We attribute this effect to anion ordering that essentially modifies the bond geometry, especially the respective bond angles as modeled by DFT.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.387
DOI: 10.1016/J.APSUSC.2020.148490
|
|
|
“Magnetic Ordering in the Layered Cr(II) Oxide Arsenides Sr2CrO2Cr2As2and Ba2CrO2Cr2As2”. Xu X, Jones MA, Cassidy SJ, Manuel P, Orlandi F, Batuk M, Hadermann J, Clarke SJ, Inorganic Chemistry 59, 15898 (2020). http://doi.org/10.1021/acs.inorgchem.0c02415
Abstract: Sr2CrO2Cr2As2 and Ba2CrO2Cr2As2 with Cr2+ ions in CrO2 sheets and in CrAs layers crystallize with the Sr2Mn3Sb2O2 structure (space group I4/mmm, Z = 2) and lattice parameters a = 4.00800(2) Å, c = 18.8214(1) Å (Sr2CrO2Cr2As2) and a = 4.05506(2) Å, c = 20.5637(1) Å (Ba2CrO2Cr2As2) at room temperature. Powder neutron diffraction reveals checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the arsenide layers below TN1Sr, of 600(10) K (Sr2CrO2Cr2As2) and TN1Ba 465(5) K (Ba2CrO2Cr2As2) with the moments initially directed perpendicular to the layers in both compounds. Checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the oxide layer below 230(5) K for Ba2CrO2Cr2As2 occurs with these moments also perpendicular to the layers, consistent with the orientation preferences of d4 moments in the two layers. In contrast, below 330(5) K in Sr2CrO2Cr2As2, the oxide layer Cr2+ moments are initially oriented in the CrO2 plane; but on further cooling, these moments rotate to become perpendicular to the CrO2 planes, while the moments in the arsenide layers rotate by 90° with the moments on the two sublattices remaining orthogonal throughout [behavior recently reported independently by Liu et al. [Liu et al. Phys. Rev. B 2018, 98, 134416]]. In Sr2CrO2Cr2As2, electron diffraction and high resolution powder X-ray diffraction data show no evidence for a structural distortion that would allow the two Cr2+ sublattices to couple, but high resolution neutron powder diffraction data suggest a small incommensurability between the magnetic structure and the crystal structure, which may account for the coupling of the two sublattices and the observed spin reorientation. The saturation values of the Cr2+ moments in the CrO2 layers (3.34(1) μB (for Sr2CrO2Cr2As2) and 3.30(1) μB (for Ba2CrO2Cr2As2)) are larger than those in the CrAs layers (2.68(1) μB for Sr2CrO2Cr2As2 and 2.298(8) μB for Ba2CrO2Cr2As2) reflecting greater covalency in the arsenide layers.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.6
DOI: 10.1021/acs.inorgchem.0c02415
|
|
|
“Enhanced photoelectrochemical detection of an analyte triggered by its concentration by a singlet oxygen-generating fluoro photosensitizer”. Blidar A, Trashin S, Carrion EN, Gorun SM, Cristea C, De Wael K, Acs Sensors 5, 3501 (2020). http://doi.org/10.1021/ACSSENSORS.0C01609
Abstract: The use of a photocatalyst (photosensitizer) which produces singlet oxygen instead of enzymes for oxidizing analytes creates opportunities for designing cost-efficient and sensitive photoelectrochemical sensors. We report that perfluoroisopropyl-substituted zinc phthalocyanine (F64PcZn) interacts specifically with a complex phenolic compound, the antibiotic rifampicin (RIF), but not with hydroquinone or another complex phenolic compound, the antibiotic doxycycline. The specificity is imparted by the selective preconcentration of RIF in the photocatalytic layer, as revealed by electrochemical and optical measurements, complemented by molecular modeling that confirms the important role of a hydrophobic cavity formed by the iso-perfluoropropyl groups of the photocatalyst. The preconcentration effect favorably enhances the RIF photoelectrochemical detection limit as well as sensitivity to nanomolar (ppb) concentrations, LOD = 7 nM (6 ppb) and 2.8 A.M-1.cm(-2), respectively. The selectivity to RIF, retained in the photosensitizer layer, is further enhanced by the selective removal of all unretained phenols via simple washing of the electrodes with pure buffer. The utility of the sensor for analyzing municipal wastewater was demonstrated. This first demonstration of enhanced selectivity and sensitivity due to intrinsic interactions of a molecular photocatalyst (photosensitizer) with an analyte, without use of a biorecognition element, may allow the design of related, robust, simple, and viable sensors.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.9
DOI: 10.1021/ACSSENSORS.0C01609
|
|
|
“The novel method to reduce the silica content in lignin recovered from black liquor originating from rice straw”. Do NH, Pham HH, Le TM, Lauwaert J, Diels L, Verberckmoes A, Do NHN, Tran VT, Le PK, Scientific Reports 10, 21263 (2020). http://doi.org/10.1038/S41598-020-77867-5
Abstract: Difficulties in the production of lignin from rice straw because of high silica content in the recovered lignin reduce its recovery yield and applications as bio-fuel and aromatic chemicals. Therefore, the objective of this study is to develop a novel method to reduce the silica content in lignin from rice straw more effectively and selectively. The method is established by monitoring the precipitation behavior as well as the chemical structure of precipitate by single-stage acidification at different pH values of black liquor collected from the alkaline treatment of rice straw. The result illustrates the significant influence of pH on the physical and chemical properties of the precipitate and the supernatant. The simple two-step acidification of the black liquor at pilot-scale by sulfuric acid 20w/v% is applied to recover lignin at pH 9 and pH 3 and gives a percentage of silica removal as high as 94.38%. Following the developed process, the high-quality lignin could be produced from abundant rice straw at the industrial-scale.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 4.6
DOI: 10.1038/S41598-020-77867-5
|
|
|
“Identifying alternative ferroelectric materials beyond Hf(Zr)O-₂”. Guo J, Clima S, Pourtois G, Van Houdt J, Applied Physics Letters 117, 262903 (2020). http://doi.org/10.1063/5.0028611
Abstract: A database-driven approach combined with ab initio density functional theory (DFT) simulations is used to identify and simulate alternative ferroelectric materials beyond Hf(Zr)O-2. The database-driven screening method identifies a class of wurtzite ferroelectric materials. DFT simulations of wurtzite magnesium chalcogenides, including MgS, MgSe, and MgTe, show their potential to achieve improved ferroelectric (FE) stability, simple atomistic unit cell structure, and large FE polarization. Strain engineering can effectively modulate the FE switching barrier height for facilitating FE switching. The effect of the piezoelectric property on the FE switching barrier heights is also examined.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4
DOI: 10.1063/5.0028611
|
|
|
“Electronic and magnetic properties of single-layer FeCl₂, with defects”. Ceyhan E, Yagmurcukardes M, Peeters FM, Sahin H, Physical Review B 103, 014106 (2021). http://doi.org/10.1103/PHYSREVB.103.014106
Abstract: The formation of lattice defects and their effect on the electronic properties of single-layer FeCl2 are investigated by means of first-principles calculations. Among the vacancy defects, namely mono-, di-, and three-Cl vacancies and mono-Fe vacancy, the formation of mono-Cl vacancy is the most preferable. Comparison of two different antisite defects reveals that the formation of the Fe-antisite defect is energetically preferable to the Cl-antisite defect. While a single Cl vacancy leads to a 1 mu(B) decrease in the total magnetic moment of the host lattice, each Fe vacant site reduces the magnetic moment by 4 mu(B). However, adsorption of an excess Cl atom on the surface changes the electronic structure to a ferromagnetic metal or to a ferromagnetic semiconductor depending on the adsorption site without changing the ferromagnetic state of the host lattice. Both Cl-antisite and Fe-antisite defected domains change the magnetic moment of the host lattice by -1 mu(B) and +3 mu(B), respectively. The electronic ground state of defected structures reveals that (i) single-layer FeCl2 exhibits half-metallicity under the formation of vacancy and Cl-antisite defects; (ii) ferromagnetic metallicity is obtained when a single Cl atom is adsorbed on upper-Cl and Fe sites, respectively; and (iii) ferromagnetic semiconducting behavior is found when a Cl atom is adsorbed on a lower-Cl site or a Fe-antisite defect is formed. Simulated scanning electron microscope images show that atomic-scale identification of defect types is possible from their electronic charge density. Further investigation of the periodically Fe-defected structures reveals that the formation of the single-layer FeCl3 phase, which is a dynamically stable antiferromagnetic semiconductor, is possible. Our comprehensive analysis on defects in single-layer FeCl2 will complement forthcoming experimental observations.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 7
DOI: 10.1103/PHYSREVB.103.014106
|
|
|
“Farmers' decision to use drought early warning system in developing countries”. Sharafi L, Zarafshani K, Keshavarz M, Azadi H, Van Passel S, Science Of The Total Environment 758, 142761 (2021). http://doi.org/10.1016/J.SCITOTENV.2020.142761
Abstract: Drought is a persistent, sluggish natural disaster in developing countries that has generated a financial burden and an unstable climate. Farmers should adopt early warning systems (EWS) in their strategies for monitoring drought to reduce its serious consequences. However, farmers in developing countries are reluctant to use EWS as their management strategies. Hence, the aim of this study was to investigate the decision of farmers to use climate knowledge through the model of farming activity in Kermanshah Township, Iran. A surveyor questionnaire was used to gather data from 370 wheat farmers using random sampling methods inmulti-stage clusters. Results revealed that the decision to use climate information is affected by personal factors, attitude towards climate information, objectives of using climate information, and external/physical farming factors. The result of this study has implications for drought management practitioners. To be specific, the results can aid policymakers to design early alert programs to minimize the risk of drought and thus move from conventional to climate smart agriculture. (C) 2020 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Engineering Management (ENM)
Impact Factor: 4.9
DOI: 10.1016/J.SCITOTENV.2020.142761
|
|