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“Sn19.3Cu4.7As22I8: a new clathrate-I compound with transition-metal atoms in the cationic framework”. Kovnir KA, Sobolev AV, Presniakov IA, Lebedev OI, Van Tendeloo G, Schnelle W, Grin Y, Shevelkov AV, Inorganic chemistry 44, 8786 (2005). http://doi.org/10.1021/ic051160k
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.857
Times cited: 38
DOI: 10.1021/ic051160k
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“On the nature of ferromagnetism in diluted magnetic semiconductors : GaAs:Mn”. Krstajic PM, Ivanov VA, Peeters FM, Fleurov V, Kikoin K, Europhysics letters 61, 235 (2003). http://doi.org/10.1209/epl/i2003-00224-x
Abstract: An energy level diagram is constructed on the basis of a microscopic Hamiltonian proposed for a description of interacting manganese impurities in diluted magnetic semiconductors (DMS). It is shown that ferromagnetism in p-type III-V DMS is governed by the strong hybridization of Mn2+-electrons with the mobile holes and localized states near the top of the valence band. The Curie temperature estimated from the proposed kinematic exchange agrees with the experiments on GaAs:Mn. The model is also applicable to the GaP:Mn system.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.957
Times cited: 38
DOI: 10.1209/epl/i2003-00224-x
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“The role of oxygen at the interface between titanium and carbon nanotubes”. Felten A, Suarez-Martinez I, Ke X, Van Tendeloo G, Ghijsen J, Pireaux J-J, Drube W, Bittencourt C, Ewels CP, ChemPhysChem : a European journal of chemical physics and physical chemistry 10, 1799 (2009). http://doi.org/10.1002/cphc.200900193
Abstract: We study the interface between carbon nanotubes (CNTs) and surface-deposited titanium using electron microscopy and photoemission spectroscopy, supported by density functional calculations. Charge transfer from the Ti atoms to the nanotube and carbide formation is observed at the interface which indicates strong interaction. Nevertheless, the presence of oxygen between the Ti and the CNTs significantly weakens the Ti-CNT interaction. Ti atoms at the surface will preferentially bond to oxygenated sites. Potential sources of oxygen impurities are examined, namely oxygen from any residual atmosphere and pre-existing oxygen impurities on the nanotube surface, which we enhance through oxygen plasma surface pre-treatment. Variation in literature data concerning Ohmic contacts between Ti and carbon nanotubes is explained via sample pre-treatment and differing vacuum levels, and we suggest improved treatment routes for reliable Schottky barrier-free Ti-nanotube contact formation.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.075
Times cited: 38
DOI: 10.1002/cphc.200900193
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“ZnO nanorod arrays by plasma-enhanced CVD for light-activated functional applications”. Bekermann D, Gasparotto A, Barreca D, Devi A, Fischer RA, Kete M, Štangar UL, Lebedev OI, Maccato C, Tondello E, Van Tendeloo G, ChemPhysChem : a European journal of chemical physics and physical chemistry 11, 2337 (2010). http://doi.org/10.1002/cphc.201000333
Abstract: Switch of the surface properties: Supported ZnO nanorod arrays with tailored roughness and aspect ratios are successfully synthesized by plasma-enhanced chemical vapor deposition. Such nanostructures exhibit significant superhydrophilic and photocatalytic properties tunable as a function of their morphological organization (see picture). This renders them promising building blocks for the fabrication of stimuli-responsive materials.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.075
Times cited: 38
DOI: 10.1002/cphc.201000333
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“Titanosilicate beads with hierarchical porosity : synthesis and application as epoxidation catalysts”. Lin K, Lebedev OI, Van Tendeloo G, Jacobs PA, Pescarmona PP, Chemistry: a European journal 16, 13509 (2011). http://doi.org/10.1002/chem.201001508
Abstract: Porous titanosilicate beads with a diameter of 0.51.5 mm (TiSil-HPB-60) were synthesized from a preformed titanosilicate solution with a porous anion-exchange resin as template. The bead format of this material enables its straightforward separation from the reaction mixture in its application as a liquid-phase heterogeneous catalyst. The material displays hierarchical porosity (micro/mesopores) and incipient TS-1 structure building units. The titanium species are predominantly located in tetrahedral framework positions. TiSil-HPB-60 is a highly active catalyst for the epoxidation of cyclohexene with t-butyl hydroperoxide (TBHP) and aqueous H2O2. With both oxidants, TiSil-HPB-60 gave higher epoxide yields than Ti-MCM-41 and TS-1. The improved catalytic performance of TiSil-HPB-60 is mainly ascribed to the large mesopores favoring the diffusion of reagents and products to and from the titanium active sites. The epoxide yield and selectivity could be further improved by silylation of the titanosilicate beads. Importantly, TiSil-HPB-60 is a stable catalyst immune to titanium leaching, and can be easily recovered and reused in successive catalytic cycles without significant loss of activity. Moreover, TiSil-HPB-60 is active and selective in the epoxidation of a wide range of bulky alkenes.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.317
Times cited: 38
DOI: 10.1002/chem.201001508
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“Chemistry of trimethyl aluminum: a spontaneous route to thermally stable 3D crystalline macroporous alumina foams with a hierarchy of pore sizes”. Li Y, Yang X-Y, Tian G, Vantomme A, Yu J, Van Tendeloo G, Su B-L, Chemistry of materials 22, 3251 (2010). http://doi.org/10.1021/cm100491r
Abstract: A simple and spontaneous one-pot self-formation procedure that is easy to scale up has been developed based on the chemistry of trimethylaluminum (TMA), leading to thermally stable macroporous crystalline alumina with a very unique and unprecedented three-dimensional (3D) hierarchical pore structure consisting of well-defined wormlike mesopores. TMA is the precursor of both product and porogene (viz, two working functions within the same molecule (2 in 1)). The materials obtained have been intensively characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption−desorption, and mercury porosimetry. The open cagelike macrocavities are self-constructed by mesoporous nanorods (diameter of ca. 40−70 nm), which are themselves formed by a random assembly of fibrous nanoparticles 5−6 nm in size. Optical microscopy (OM) has been used in situ to follow the synthesis procedure, which led to the proposal of the formation mechanism. Methane molecules as porogens, which were instantaneously released because of the fast hydrolysis of the chemical precursor, were the key factor in producing these 3D structures with uniform co-continuous macropores that interconnected directly with the wormlike mesopores. The important characteristic of this procedure is the concurrent formation of a multiscaled porous network. The material exhibits great thermal stability. The hierarchically mesoporous−macroporous Al2O3 obtained is quite attractive for a myriad of applications, from catalysis to biomedicine. The present work illustrates that the one-pot self-formation concept, based on the chemistry of alkyl metals, is a versatile method to design industrially valuable hierarchically porous materials.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 38
DOI: 10.1021/cm100491r
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“Gliding arc plasma for CO 2 conversion: Better insights by a combined experimental and modelling approach”. Wang W, Mei D, Tu X, Bogaerts A, Chemical engineering journal 330, 11 (2017). http://doi.org/10.1016/j.cej.2017.07.133
Abstract: A gliding arc plasma is a potential way to convert CO2 into CO and O2, due to its non-equilibrium character, but little is known about the underlying mechanisms. In this paper, a self-consistent two-dimensional (2D) gliding arc model is developed, with a detailed non-equilibrium CO2 plasma chemistry, and validated with experiments. Our calculated values of the electron number density in the plasma, the CO2 conversion and energy efficiency show reasonable agreement with the experiments, indicating that the model can provide a realistic picture of the plasma chemistry. Comparison of the results with classical thermal conversion, as well as other plasma-based technologies for CO2 conversion reported in literature, demonstrates the non-equilibrium character of the gliding arc, and indicates that the gliding arc is a promising plasma reactor for CO2 conversion. However, some process modifications should be exploited to further improve its performance. As the model provides a realistic picture of the plasma behaviour, we use it first to investigate the plasma characteristics in a whole gliding arc cycle, which is necessary to understand the underlying mechanisms. Subsequently, we perform a chemical kinetics analysis, to investigate the different pathways for CO2 loss and formation. Based on the revealed discharge properties and the underlying CO2 plasma chemistry, the model allows us to propose solutions on how to further improve the
CO2 conversion and energy efficiency by a gliding arc plasma.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 6.216
Times cited: 38
DOI: 10.1016/j.cej.2017.07.133
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“Probing the interaction between gold nanoparticles and oxygen functionalized carbon nanotubes”. Suarez-Martinez I, Bittencourt C, Ke X, Felten A, Pireaux JJ, Ghijsen J, Drube W, Van Tendeloo G, Ewels CP, Carbon 47, 1549 (2009). http://doi.org/10.1016/j.carbon.2009.02.002
Abstract: The interaction between evaporated gold and pristine or oxygen plasma treated multi-walled carbon nanotubes (MWCNTs) is investigated. Experimental and theoretical results indicate that gold nucleation occurs at defect sites, whether initially present or introduced by oxygen plasma treatment. Uniform gold cluster dispersion is observed on plasma treated carbon nanotubes (CNTs) and associated with the presence of uniformly dispersed oxidized vacancy centres on the CNT surface.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.337
Times cited: 38
DOI: 10.1016/j.carbon.2009.02.002
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“Phytoremediation, a sustainable remediation technology? 2 : economic assessment of CO2 abatement through the use of phytoremediation crops for renewable energy production”. Witters N, Mendelsohn R, Van Passel S, Van Slycken S, Weyens N, Schreurs E, Meers E, Tack F, Vanheusden B, Vangronsveld J, Biomass &, Bioenergy 39, 470 (2012). http://doi.org/10.1016/J.BIOMBIOE.2011.11.017
Abstract: Phytoremediation could be a sustainable remediation alternative for conventional remediation technologies. However, its implementation on a commercial scale remains disappointing. To emphasize its sustainability, this paper examines whether and how the potential economic benefit of CO2 abatement for different crops used for phytoremediation or sustainable land management purposes could promote phytotechnologies. Our analysis is based on a case study in the Campine region, where agricultural soils are contaminated with mainly cadmium. We use Life Cycle Analysis to show for the most relevant crops (willow (Salix spp), energy maize (Zea mays), and rapeseed (Brassica napus)), that phytoremediation, used for renewable energy production, could abate CO2. Converting this in economic numbers through the Marginal Abatement Cost of CO2 ( 20 ton−1) we can integrate this in the economic analysis to compare phytoremediation crops among each other, and phytoremediation with conventional technologies. The external benefit of CO2 abatement when using phytoremediation crops for land management ranges between 55 and 501 per hectare. The purpose of these calculations is not to calculate a subsidy for phytoremediation. There is no reason why one would prefer phytoremediation crops for renewable energy production over normal biomass. Moreover, subsidies for renewable energy already exist. Therefore, we should not integrate these numbers in the economic analysis again. However, these numbers could contribute to making explicit the competitive advantage of phytoremediation compared to conventional remediation technologies, but also add to a more sustainably funded decision on which crop should be grown on contaminated land.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 3.219
Times cited: 38
DOI: 10.1016/J.BIOMBIOE.2011.11.017
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“High strength-ductility of thin nanocrystalline palladium films with nanoscale twins : on-chip testing and grain aggregate model”. Colla M-S, Wang B, Idrissi H, Schryvers D, Raskin J-P, Pardoen T, Acta materialia 60, 1795 (2012). http://doi.org/10.1016/j.actamat.2011.11.054
Abstract: The mechanical behaviour of thin nanocrystalline palladium films with an ∼30 nm in plane grain size has been characterized on chip under uniaxial tension. The films exhibit a large strain hardening capacity and a significant increase in the strength with decreasing thickness. Transmission electron microscopy has revealed the presence of a moderate density of growth nanotwins interacting with dislocations. A semi-analytical grain aggregate model is proposed to investigate the impact of different contributions to the flow behaviour, involving the effect of twins, of grain size and of the presence of a thin surface layer. This model provides guidelines to optimizing the strength/ductility ratio of the films.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 5.301
Times cited: 38
DOI: 10.1016/j.actamat.2011.11.054
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“Self-organized platinum nanoparticles on freestanding graphene”. Xu P, Dong L, Neek-Amal M, Ackerman ML, Yu J, Barber SD, Schoelz JK, Qi D, Xu F, Thibado PM, Peeters FM;, ACS nano 8, 2697 (2014). http://doi.org/10.1021/nn406394f
Abstract: Freestanding graphene membranes were successfully functionalized with platinum nanoparticles (Pt NPs). High-resolution transmission electron microscopy revealed a homogeneous distribution of single-crystal Pt NPs that tend to exhibit a preferred orientation. Unexpectedly, the NPs were also found to be partially exposed to the vacuum with the top Pt surface raised above the graphene substrate, as deduced from atomic-scale scanning tunneling microscopy images and detailed molecular dynamics simulations. Local strain accumulation during the growth process is thought to be the origin of the NP self-organization. These findings are expected to shape future approaches in developing Pt NP catalysts for fuel cells as well as NP-functionalized graphene-based high-performance electronics.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 13.942
Times cited: 38
DOI: 10.1021/nn406394f
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