“Disproportionation of Co2+ in the topochemically reduced oxide LaSrCoRuO₅”. Liang Z, Batuk M, Orlandi F, Manuel P, Hadermann J, Hayward MA, Angewandte Chemie: international edition in English 63, e202313067 (2024). http://doi.org/10.1002/ANIE.202313067
Abstract: Complex transition-metal oxides exhibit a wide variety of chemical and physical properties which are a strong function the local electronic states of the transition-metal centres, as determined by a combination of metal oxidation state and local coordination environment. Topochemical reduction of the double perovskite oxide, LaSrCoRuO6, using Zr, yields LaSrCoRuO5. This reduced phase contains an ordered array of apex-linked square-based pyramidal Ru3+O5, square-planar Co1+O4 and octahedral Co3+O6 units, consistent with the coordination-geometry driven disproportionation of Co2+. Coordination-geometry driven disproportionation of d(7) transition-metal cations (e.g. Rh2+, Pd3+, Pt3+) is common in complex oxides containing 4d and 5d metals. However, the weak ligand field experienced by a 3d transition-metal such as cobalt leads to the expectation that d(7+) Co2+ should be stable to disproportionation in oxide environments, so the presence of Co1+O4 and Co3+O6 units in LaSrCoRuO5 is surprising. Low-temperature measurements indicate LaSrCoRuO5 adopts a ferromagnetically ordered state below 120 K due to couplings between S=(1)/(2) Ru3+ and S=1 Co1+.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 16.6
DOI: 10.1002/ANIE.202313067
|
“Displacive and diffusive components in the formation of the Ni2Al structure studied by HREM, SAED and micro-ED”. Muto S, Merk N, Schryvers D, Tanner LE, Monterey Institute for Advances Studies , 101 (1992)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
|
“Dispersion of heavy metals”. Van Grieken R page 319 (1998).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
“Dispersion modelling of traffic induced ultrafine particles in a street canyon in Antwerp, Belgium and comparison with observations”. Nikolova I, Janssen S, Vos P, Vrancken K, Mishra V, Berghmans P, The science of the total environment 412, 336 (2011). http://doi.org/10.1016/J.SCITOTENV.2011.09.081
Abstract: The aim of this study is to investigate the dispersion of ultrafine particles and its spatial distribution in a street canyon and its neighbourhood with the 3D CFD model ENVI-met®. The performance of the model at street scale is evaluated and the importance of the boundary conditions like wind field and traffic emissions on the UFP concentration is demonstrated. To support and validate the modelled results, a short-term measurement campaign was conducted in a street canyon in Antwerp, Belgium. The UFP concentration was measured simultaneously with P-TRACK (TSI Model 8525) at four different locations in the canyon. The modelled UFP concentrations compare well with the measured data (correlation coefficient R from 0.44 to 0.93) within the standard deviation of the measurements. Despite the moderate traffic flow in the street canyon, UFP concentrations in the canyon are in general double of the background concentrations, indicating the high local contribution for this particle number concentration. Some of the observed concentration profiles are not resembled by the model simulations. For these specific anomalies, further analysis is performed and plausible explanations are put forward. The role of wind direction and traffic emissions is investigated. The performance evaluation of ENVI-met® shows that in general the model qualitatively and quantitatively describes the dispersion of UFP in the street canyon study.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.SCITOTENV.2011.09.081
|
“Dispersal of suspended matter in Makasar Strait and the Flores Basin”. Eisma D, Kalf J, Karmini M, Mook WG, Van Put A, Bernard P, Van Grieken R, Netherlands journal of sea research 24, 383 (1989). http://doi.org/10.1016/0077-7579(89)90116-6
Abstract: In November 1984 in Makasar and the Flores Basin water samples were collected (T, S, dissolved O2, total CO2), bottom samples (sediment composition) and suspended matter (particle composition, particle size). A sediment trap was moored in the Flores Basin at 4600 m depth for nearly four months, covering the dry season. In the Flores Basin there are indications for bottom flow resuspending bottom material or preventing suspended material from settling; in Makasar Strait there is probably inflow of deep water both from the south and from the north, resulting in a very slow bottom water flor. Bottom deposits in Makasar Strait and the Flores Basin are predominantly terrigenous, with an admixture of organic carbonate and silica (mostly coccoliths). Volcanic material is primarily present near to the volcanoes in the south and reaches the deeper basins by slumping. In the suspended matter no volcanic particles and little planktonic material were found, although the latter form 10 to 15% of the top sediment and of the material deposited in the sediment trap. In suspension particles with a large concentration of tin (Sn) were found associated mainly with iron. They probably come from northern Kalimantan or northern Sulawesi. Suspended matter concentrations were mainly less than 0.5 mg·dm−3, only off the Mahakam river mouth were concentrations higher than 1 mg·dm−3. Particle size was erratic because of the variable composition of the coarser particles in suspension. Organic matter concentrations in suspension (in mg·dm−3) roughly follow the distribution of total suspended matter but organic content (in %) of the suspended matter does not show any trends. All organic matter in suspension is of marine origin except in the Mahakam river and estuary. Deposition rates, as estimated from the sediment trap results, are 150 mg·cm−2·a−1 for the total sediment, 26 mg·cm−2·a−1 for carbonate and 13 mg·cm−2·a−1 for organic matter. Flocs and fibres in suspension were only found in and below the Mahakam river plume that reaches ca 400 km from the river mouth to the southeast, and in surface waters associated with plankton (diatoms). The formation of these flocs (broken-up macroflocs or marine snow) is primarily related to particle concentration, turbulence, and the presence of organisms that produce sticky material or glue particles together.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0077-7579(89)90116-6
|
“Discrimination between coprecipitated and adsorbed lead on individual calcite particles using laser microprobe mass analysis”. Wouters LC, Van Grieken RE, Linton RW, Bauer CF, Analytical chemistry 60, 2218 (1988). http://doi.org/10.1021/AC00171A011
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC00171A011
|
“Discovery of core-shell quasicrystalline particles”. Yang T, Kong Y, Du Y, Li K, Schryvers D, Scripta materialia 222, 115040 (2023). http://doi.org/10.1016/J.SCRIPTAMAT.2022.115040
Abstract: Submicron-sized quasicrystalline particles were obtained in an Al-Zn-Mg-Cu alloy produced by traditional melting. These particles consist of an Al-Fe-Ni core and a Mg-Cu-Zn shell and were found to be stable and embedded randomly in the Al matrix. The diffraction patterns of these core-shell particles reveal a decagonal core and an icosahedral shell with, respectively, ten- and five-fold axes aligned. High resolution scanning transmission electron microscopy of the Mg-Cu-Zn shell confirms the five-fold symmetry atomic arrangement and the icosahedral structure. It can therefore be concluded that Fe and Ni impurities play an important role in mediating the formation of such an unusual ternary core-shell quasicrystalline particle. These findings provide some novel insights in the formation of quasicrystals in traditional industrial Al alloys.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 6
DOI: 10.1016/J.SCRIPTAMAT.2022.115040
|
“Directly revealing the structure-property correlation in Na+-doped cathode materials”. Li C-F, Chen L-D, Wu L, Liu Y, Hu Z-Y, Cui W-J, Dong W-D, Liu X, Yu W-B, Li Y, Van Tendeloo G, Su B-L, Applied surface science 612, 155810 (2023). http://doi.org/10.1016/J.APSUSC.2022.155810
Abstract: The introduction of Na+ is considered as an effective way to improve the performance of Ni-rich cathode materials. However, the direct structure-property correlation for Na+ doped NCM-based cathode materials remain unclear, due to the difficulty of local and accurate structural characterization for light elements such as Li and Na. Moreover, there is the complexity of the modeling for the whole Li ion battery (LIB) system. To tackle the above-mentioned issues, we prepared Na+-doped LiNi0.6Co0.2Mn0.2O2 (Na-NCM622) material. The crystal structure change and the lattice distortion with picometers precision of the Na+-doped material is revealed by Cs-corrected scanning transmission electron microscopy (STEM). Density functional theory (DFT) and the recently proposed electrochemical model, i.e., modified Planck-Nernst-Poisson coupled Frumkin-Butler-Volmer (MPNP-FBV), has been applied to reveal correlations between the activation energy and the charge transfer resistance at multiscale. It is shown that Na+ doping can reduce the activation energy barrier from. G = 1.10 eV to 1.05 eV, resulting in a reduction of the interfacial resistance from 297 O to 134 Omega. Consequently, the Na-NCM622 cathode delivers a superior capacity retention of 90.8 % (159 mAh.g(-1)) after 100 cycles compared to the pristine NCM622 (67.5 %, 108 mAh.g(-1)). Our results demonstrate that the kinetics of Li+ diffusion and the electrochemical reaction can be enhanced by Na+ doping the cathode material.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.7
DOI: 10.1016/J.APSUSC.2022.155810
|
“Direct visualization of atomic-scale heterogeneous structure dynamics in MnO₂, nanowires”. Peng X, Peng H, Zhao K, Zhang Y, Xia F, Lyu J, Van Tendeloo G, Sun C, Wu J, Acs Applied Materials &, Interfaces 13, 33644 (2021). http://doi.org/10.1021/ACSAMI.1C07929
Abstract: Manganese oxides are attracting great interest owing to their rich polymorphism and multiple valent states, which give rise to a wide range of applications in catalysis, capacitors, ion batteries, and so forth. Most of their functionalities are connected to transitions among the various polymorphisms and Mn valences. However, their atomic-scale dynamics is still a great challenge. Herein, we discovered a strong heterogeneity in the crystalline structure and defects, as well as in the Mn valence state. The transitions are studied by in situ transmission electron microscopy (TEM), and they involve a complex ordering of [MnO6] octahedra as the basic building tunnels. MnO2 nanowires synthesized using solution-based hydrothermal methods usually exhibit a large number of multiple polymorphism impurities with different tunnel sizes. Upon heating, MnO2 nanowires undergo a series of stoichiometric polymorphism changes, followed by oxygen release toward an oxygen-deficient spinel and rock-salt phase. The impurity polymorphism exhibits an abnormally high stability with interesting small-large-small tunnel size transition, which is attributed to a preferential stabilizer (K+) concentration, as well as a strong competition of kinetics and thermodynamics. Our results unveil the complicated intergrowth of polymorphism impurities in MnO2, which provide insights into the heterogeneous kinetics, thermodynamics, and transport properties of the tunnel-based building blocks.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.504
DOI: 10.1021/ACSAMI.1C07929
|
“Direct sensing of superoxide and its relatives reactive oxygen and nitrogen species in phosphate buffers during cold atmospheric plasmas exposures”. Girard-Sahun F, Lefrancois P, Badets V, Arbault S, Clement F, Analytical Chemistry 94, 5555 (2022). http://doi.org/10.1021/ACS.ANALCHEM.1C04998
Abstract: This study aims at sensing in situ reactive oxygen and nitrogen species (RONS) and specifically superoxide anion (O-2(center dot-)) in aqueous buffer solutions exposed to cold atmospheric plasmas (CAPs). CAPs were generated by ionizing He gas shielded with variable N-2/O-2 mixtures. Thanks to ultramicroelectrodes protected against the high electric fields transported by the ionization waves of CAPs, the production of superoxide and several RONS was electrochemically directly detected in liquids during their plasma exposure. Complementarily, optical emissive spectroscopy (OES) was used to study the plasma phase composition and its correlation with the chemistry in the exposed liquid. The specific production of O-2(center dot-), a biologically reactive redox species, was analyzed by cyclic voltammetry (CV), in both alkaline (pH 11), where the species is fairly stable, and physiological (pH 7.4) conditions, where it is unstable. To understand its generation with respect to the plasma chemistry, we varied the shielding gas composition of CAPs to directly impact on the RONS composition at the plasma-liquid interface. We observed that the production and accumulation of RONS in liquids, including O(2)(center dot-)depends on the plasma composition, with N-2-based shieldings providing the highest superoxide concentrations (few 10s of micromolar at most) and of its derivatives (hundreds of micromolar). In situ spectroscopic and electrochemical analyses provide a high resolution kinetic and quantitative understanding of the interactions between CAPs and physiological solutions for biomedical applications.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.4
DOI: 10.1021/ACS.ANALCHEM.1C04998
|
“Direct reagentless detection of the affinity binding of recombinant His-tagged firefly luciferase with a nickel-modified gold electrode”. Vagin MY, Trashin SA, Beloglazkina EK, Majouga AG, Mendeleev communications 25, 290 (2015). http://doi.org/10.1016/J.MENCOM.2015.07.021
Abstract: The direct reagentless electrochemical detection of recombinant firefly luciferase binding with a gold electrode modified with nickel complex of 1,16-di[4-(2,6-dihydroxycarbonyl)pyridyl]-1,16-dioxa-8,9-dithiahexadecane has been carried out.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.MENCOM.2015.07.021
|
“Direct observation of layer-stacking and oriented wrinkles in multilayer hexagonal boron nitride”. Chen L, Elibol K, Cai H, Jiang C, Shi W, Chen C, Wang HS, Wang X, Mu X, Li C, Watanabe K, Taniguchi T, Guo Y, Meyer JC, Wang H, 2d Materials 8, 024001 (2021). http://doi.org/10.1088/2053-1583/ABD41E
Abstract: Hexagonal boron nitride (h-BN) has long been recognized as an ideal substrate for electronic devices due to its dangling-bond-free surface, insulating nature and thermal/chemical stability. These properties of the h-BN multilayer are mainly determined by its lattice structure. Therefore, to analyse the lattice structure and orientation of h-BN crystals becomes important. Here, the stacking order and wrinkles of h-BN are investigated by transmission electron microscopy. It is experimentally confirmed that the layers in the h-BN flakes are arranged in the AA ' stacking. The wrinkles in a form of threefold network throughout the h-BN crystal are oriented along the armchair direction, and their formation mechanism was further explored by molecular dynamics simulations. Our findings provide a deep insight about the microstructure of h-BN and shed light on the structural design/electronic modulations of two-dimensional crystals.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.937
DOI: 10.1088/2053-1583/ABD41E
|
“Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps”. Cui W, Lin W, Lu W, Liu C, Gao Z, Ma H, Zhao W, Van Tendeloo G, Zhao W, Zhang Q, Sang X, Nature communications 14, 554 (2023). http://doi.org/10.1038/S41467-023-35972-9
Abstract: Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 16.6
DOI: 10.1038/S41467-023-35972-9
|
“Direct detection of sulfate and nitrate layers on sampled marine aerosols by laser microprobe mass analysis”. Bruynseels F, Van Grieken R, Atmospheric environment 19, 1969 (1985). http://doi.org/10.1016/0004-6981(85)90023-X
Abstract: The direct detection of sulfate and nitrate layers on sampled marine aerosols was carried out by laser microprobe mass analysts.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0004-6981(85)90023-X
|
“Direct current glow discharge mass spectrometry for elemental characterization of polymers”. Schelles W, Van Grieken R, Analytical chemistry 69, 2931 (1997). http://doi.org/10.1021/AC970186T
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC970186T
|
“Direct current glow discharge mass spectrometric analysis of Macor ceramic using a secondary cathode”. Schelles W, Van Grieken R, Analytical chemistry 68, 3570 (1996). http://doi.org/10.1021/AC960441U
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC960441U
|
Berthelot A, Kolev S, Bogaerts A (2015) Different pressure regimes of a surface-wave discharge in argon : a modelling investigation. UCO Press, Cordoba, 57–62
Keywords: P2 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
|
“Die risikoprofiel van Pb en Cr in stedelike padstof”. Potgieter-Vermaak S, Van Grieken R, Potgieter H, Litnet akademies : 'n joernaal vir die geesteswetenskappe 9, 1 (2012)
Abstract: The risk profile of Cr and Pb in urban road deposited sediment Exponential urbanisation and industrial growth occur on a global scale and result in an ecological burden, of which one important part is pollution. It is well known that the extent of air pollution has escalated over the past two decades in several parts of the world, despite mitigating measures and legislation. Current research points to the fact that air pollution in urban and industrial areas is substantially different from that found in rural areas. Road dust (RD) contributes up to 35% of airborne particulate matter due to resuspension thereof, and poses a health concern due to carcinogenic and toxic components potentially present in the micron-sized fractions. Although literature does report on the concentrations of trace, toxic metals and metalloids present in RD (Hooker and Nathanail 2006), the molecular make-up of particulates generated due to the resuspension of the RD is not well documented. In vitro and animal toxicological studies have confirmed that the chemical composition of inhaled particles plays a major role in its toxic, genotoxic and carcinogenic mechanisms, but the component-specific toxic effects are still not understood. Transition metals binding to air particle matter can result in reactive oxygen species in the human body (particularly in the lungs), and this is a significant risk, especially for vulnerable population groups like elderly people, children and terminally ill patients. The characterisation of the molecular composition of the fine fraction is evidently of importance for public health. During an earlier study, road dust from an inner-city environment in the UK was collected and partially characterised (Barrett e.a. 2010). These same-size fractions were analysed for their elemental concentrations, using X-ray Fluorescence Spectrometry (XRFS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In addition, single-particle analysis was performed on the different fractions by means of Computer Controlled Electron Probe X-ray Micro Analysis (CC-EPXMA) and their molecular structure probed by studying elemental associations. These findings were correlated with Micro Raman Spectroscopy (MRS) results. It was found that the fine fraction (<38 μm) had the highest Pb (238 ppm) and Cr (171 ppm) concentrations. The CC-EPXMA data showed >50% association of Cr-rich particles with Pb and the MRS data showed that the Cr was mostly present as lead chromate and therefore in the Cr(VI) oxidation state. Concentrations of both Pb and Cr decreased substantially (279 (<38 mm) 13 ppm (<1mm); 171 (<38 mm) 91 ppm (<1mm) respectively) in the larger fractions. Apart from rather alarmingly high concentrations of oxidative stressors (Cu, Fe, Mn), the carcinogenic and toxic potential of the inhalable fraction is evident. Preliminary bioaccessibility data indicated that both Cr and Pb are readily
Keywords: A2 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
“Diatom silica-titania materials for photocatalytic air purification”. Van Eynde E, Tytgat T, Smits M, Verbruggen S, Hauchecorne B, Blust R, Lenaerts S, Communications in agricultural and applied biological sciences 1, 141 (2013)
Keywords: A2 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
|
“Diatom silica-titania materials for photocatalytic air purification”. Van Eynde E, Lenaerts S page 240 (2012).
Keywords: H3 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
|
“Diatom frustule morphogenesis and function : a multidisciplinary survey”. De Tommasi E, Gielis J, Rogato A, Marine Genomics 35, 1 (2017). http://doi.org/10.1016/J.MARGEN.2017.07.001
Abstract: Diatoms represent the major component of phytoplankton and are responsible for about 2025% of global primary production. Hundreds of millions of years of evolution led to tens of thousands of species differing in dimensions and morphologies. In particular, diatom porous silica cell walls, the frustules, are characterized by an extraordinary, species-specific diversity. It is of great interest, among the marine biologists and geneticists community, to shed light on the origin and evolutionary advantage of this variability of dimensions, geometries and pore distributions. In the present article the main reported data related to frustule morphogenesis and functionalities with contributions from fundamental biology, genetics, mathematics, geometry and physics are reviewed.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.1016/J.MARGEN.2017.07.001
|
“DFT study of the hyperfine parameters and magnetic properties of ZnO doped with 57Fe”. Abreu Y, Cruz CM, Pinera I, Leyva A, Cabal AE, van Espen P, Solid state communications 185, 25 (2014). http://doi.org/10.1016/J.SSC.2014.01.010
Abstract: Magnetic state of Fe-57 implanted and doped ZnO samples have been reported and studied by Mossbauer spectroscopy at different temperatures. The Mossbauer spectra mainly showed four doublets and three sextets, but some ambiguous identification remains regarding the probe site location and influence of defects in the hyperfine and magnetic parameters. In the present work some possible implantation configurations are suggested and evaluated using Monte Carlo simulation and electronic structure calculations within the density functional theory. Various implantation environments were proposed and studied considering the presence of defects. The obtained Fe-57 hyperfine parameters show a good agreement with the reported experimental values for some of these configurations. The possibility of Fe pair formation, as well as a Zn site vacancy stabilization between he second and third neighborhood of the implantation site, is supported. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.SSC.2014.01.010
|
“DFT and microkinetic comparison of ru-doped porphyrin-like graphene and nanotubes toward catalytic formic acid decomposition and formation”. Nematollahi P, Ma H, Schneider WF, Neyts EC, Journal Of Physical Chemistry C 125, 18673 (2021). http://doi.org/10.1021/ACS.JPCC.1C03914
Abstract: Immobilization of single metal atoms on a solid host opens numerous possibilities for catalyst designs. If that host is a two-dimensional sheet, sheet curvature becomes a design parameter potentially complementary to host and metal composition. Here, we use a combination of density functional theory calculations and microkinetic modeling to compare the mechanisms and kinetics of formic acid decomposition and formation, chosen for their relevance as a potential hydrogen storage medium, over single Ru atoms anchored to pyridinic nitrogen in a planar graphene flake (RuN4-G) and curved carbon nanotube (RuN4-CNT). Activation barriers are lowered and the predicted turnover frequencies are increased over RuN4-CNT relative to RuN4-CNT. The results highlight the potential of curvature control as a means to achieve high performance and robust catalysts.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
DOI: 10.1021/ACS.JPCC.1C03914
|
“Devices consisting of hybrid systems: ferro-magnetic and superconducting disks on top of a heterojunction”. Peeters FM, Li XQ, Matulis A, , 253 (1997)
Keywords: P3 Proceeding; Condensed Matter Theory (CMT)
|
Mendonç,a Verbinnen CD (2022) Development of semiconductor-based photoelectrochemical sensing strategies for phenolic compounds in natural and supply water. 152 p
Abstract: A wide variety of organic and inorganic compounds have been frequently released into the environment without control by industries and agricultural activities. This has caused significant impact on the development and health of living organisms, and biodiversity. Therefore, the challenge of monitoring and/or remediation of these contaminants remains. This thesis presents the development of three sensing strategies based on photoelectrochemical sensors to monitor phenolic contaminants. The well-known semiconductors TiO2 and ZnO were used for building novel setups for nM analysis of phenolic compounds in water. The setups employing TiO2-based photosensors were integrated into a photoelectrochemical flow cell. The flow system favored higher sensitivity of the method by periodic wash sequences of the electrode, significantly reducing the electrode fouling. Firstly, a straightforward method was developed based on the immobilization of TiO2 on screen printed graphite electrodes. Under UV light, the developed photosensor presented high performance for the detection of 4- aminophenol. A second study was developed by impregnating gold nanoparticles into TiO2 structure. The incorporation of gold nanoparticles can broaden the light absorption region of TiO2 and improve its photocatalytic activity for the detection of hydroquinone under visible light. In both systems, the detection was possible due to the presence of reactive oxygen species at the surface of TiO2 upon light, which participate in the oxidation process of the analyte. By applying a reductive potential, the oxidized form of the analyte gets reduced and a measurable amperometric response proportional to the initial analyte concentration is recorded. The third proposed setup is a ZnO-based photosensor for the quantification of 4-nitrophenol under UVA light. Nanostructured ZnO was electrochemically synthesized on FTO glass without the use of catalysts or seed layer. A post-growth annealing treatment significantly improved ZnO nanorods physicochemical properties. Subsequent modification of ZnO nanorods with a photosensitizer (perylene acid) increased the photocurrent response and the sensitivity. In this system, the detection mechanism is based on the decrease of the photocurrent response at the presence of an electron harvesting molecule, such as 4-nitrophenol. The decrease in photocurrent is proportional to the increase of 4-nitrophenol concentration in the solution. The applicability of the photoelectrochemical semiconductor-based sensing setups was verified to analyze phenolic compounds in natural and supply water samples. The proposed robust and sensitive approaches were designed for the on-site monitoring of phenolic compounds. The encouraging results confirm the potential of these photosensors as promising tools for tracelevel sensing purposes.
Keywords: Doctoral thesis; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
|
Alfeld MW (2013) Development of scanning macr-XRF for the investigation of historical paintings. 264 p
Keywords: Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
Pilehvar S (2016) Development of new strategies for electrochemical aptasensing. 198 p
Keywords: Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
Roegiers J (2021) Development of combined photocatalytic and active carbon fiber technology for indoor air purification based on Multiphysics models. XXX, 197 p
Abstract: Exposure to volatile organic compounds (VOCs) remains a major public health concern. Indoor VOC concentrations typically far exceed outdoor levels due to a variety of emission sources and the stringent insulation measures that are imposed today. Many attempts have been made to use photocatalysis for indoor air purification. In an ideal situation, photocatalysis is capable of complete mineralization of VOCs to H2O and CO2, without any byproduct formation. Moreover, the process can take place at standard atmospheric conditions, i.e. ambient temperature and atmospheric pressure. However, successful exploitation is still impeded due to low conversion efficiency, significant pressure loss (and hence a high energy consumption) and byproduct formation. In the first part of this thesis an attempt was made to tackles these problems by designing a novel type of photocatalytic (PCO) reactor. The PCO device consists of a cylindrical vessel filled with TiO2-coated glass tubes and equipped with UV fluorescence lamps. It was investigated in terms of fluid dynamics, coating properties, UV-light distribution and photocatalytic activity. Experimental data was later used to develop and calibrate a Multiphysics model. The model proved to be a useful tool for designing and upscaling the PCO reactor. Consequently, an optimized prototype reactor was constructed and tested according the CEN-EN-16846-1 standard for VOC removal. Although the prototype showed promising results for lab-scale conditions, it struggled with byproduct formation when purifying ppb-level VOCs. In the second part of this thesis, activated carbon adsorption was investigated in order to combine it with photocatalysis. Activated carbon fiber was opted for its fast kinetics, high adsorption capacity and thermo-electrical regeneration. The filter was studied in detail regarding the adsorption of polar and apolar VOCs at indoor air concentration levels and regeneration capabilities. Experimental data was used to develop a Multiphysics model for activated carbon adsorption as well. Consequently, a novel type of ACF filter was developed using the Multiphysics model, which was equipped with electrodes in the tips of the pleats for effective thermal regeneration. In the last part, the combination of both ACF and PCO was studied using a realistic case study. Based on the Multiphysics model, the feasibility of a so-called hybrid air purification device could be investigated. The Multiphysics model shows promising results for this hybrid PCO-ACF system and hence, a demo setup was constructed for future research.
Keywords: Doctoral thesis; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL)
|
Hauchecorne B (2011) Development of an FTIR in situ reactor for real time study of surface reactions in photocatalysis. 155 p
Keywords: Doctoral thesis; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
|
“Development of an electrochemiluminescent oligonucleotide-based assay for the quantification of prostate cancer associated miR-141-3p in human serum”. Campos R, Thiruvottriyur Shanmugam S, Daems E, Ribeiro R, De Wael K, Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry 153, 108495 (2023). http://doi.org/10.1016/J.BIOELECHEM.2023.108495
Abstract: MicroRNAs (miRNAs) are small oligonucleotides (18–25 bases), biologically relevant for epigenetic regulation of key processes, particularly in association with cancer. Research effort has therefore been directed towards the monitoring and detection of miRNAs to progress (early) cancer diagnoses. Traditional detection strategies for miRNAs are expensive, with a lengthy time-to-result. In this study we develop an oligonucleotide-based assay using electrochemistry for the specific, selective and sensitive detection of a circulating miRNA (miR-141) associated with prostate cancer. In the assay, the excitation and readout of the signal are independent: an electrochemical stimulation followed by an optical readout. A ‘sandwich’ approach is incorporated, consisting of a biotinylated capture probe immobilised on streptavidin-functionalised surfaces and a detection probe labelled with digoxigenin. We show that the assay allows the detection of miR-141 in human serum, even in the presence of other miRNAs, with a LOD of 0.25 pM. The developed electrochemiluminescent assay has, therefore, the potential for efficient universal oligonucleotide target detection via the redesign of capture and detection probes.
Keywords: A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Impact Factor: 5
DOI: 10.1016/J.BIOELECHEM.2023.108495
|