“Pushing the limits of applicability of REBCO coated conductor films through fine chemical tuning and nanoengineering of inclusions”. Rizzo F, Augieri A, Kursumovic A, Bianchetti M, Opherden L, Sieger M, Huehne R, Haenisch J, Meledin A, Van Tendeloo G, MacManus-Driscoll JL, Celentano G, Nanoscale 10, 8187 (2018). http://doi.org/10.1039/C7NR09428K
Abstract: An outstanding current carrying performance (namely critical current density, J(c)) over a broad temperature range of 10-77 K for magnetic fields up to 12 T is reported for films of YBa2Cu3O7-x with Ba2Y(Nb,Ta)O-6 inclusion pinning centres (YBCO-BYNTO) and thicknesses in the range of 220-500 nm. J(c) values of 10 MA cm(-2) were measured at 30 K – 5 T and 10 K – 9 T with a corresponding maximum of the pinning force density at 10 K close to 1 TN m(-3). The system is very flexible regarding properties and microstructure tuning, and the growth window for achieving a particular microstructure is wide, which is very important for industrial processing. Hence, the dependence of J(c) on the magnetic field angle was readily controlled by fine tuning the pinning microstructure. Transmission electron microscopy (TEM) analysis highlighted that higher growth rates induce more splayed and denser BYNTO nanocolumns with a matching field as high as 5.2 T. Correspondingly, a strong peak at the B||c-axis is noticed when the density of vortices is lower than the nanocolumn density. YBCO-BYNTO is a very robust and reproducible composite system for high-current coated conductors over an extended range of magnetic fields and temperatures.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 9
DOI: 10.1039/C7NR09428K
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“Quantum anomalous Hall effect in a stable 1T-YN2 monolayer with a large nontrivial bandgap and a high Chern number”. Kong X, Li L, Leenaerts O, Wang W, Liu X-J, Peeters FM, Nanoscale 10, 8153 (2018). http://doi.org/10.1039/C8NR00571K
Abstract: The quantum anomalous Hall (QAH) effect is a topologically nontrivial phase, characterized by a non-zero Chern number defined in the bulk and chiral edge states in the boundary. Using first-principles calculations, we demonstrate the presence of the QAH effect in a 1T-YN2 monolayer, which was recently predicted to be a Dirac half metal without spin-orbit coupling (SOC). We show that the inclusion of SOC opens up a large nontrivial bandgap of nearly 0.1 eV in the electronic band structure. This results in the nontrivial bulk topology, which is confirmed by the calculation of Berry curvature, anomalous Hall conductance and the presence of chiral edge states. Remarkably, a QAH phase of high Chern number C = 3 is found, and there are three corresponding gapless chiral edge states emerging inside the bulk gap. Different substrates are also chosen to study the possible experimental realization of the 1T-YN2 monolayer, while retaining its nontrivial topological properties. Our results open a new avenue in searching for QAH insulators with high temperature and high Chern numbers, which can have nontrivial practical applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 7.367
Times cited: 28
DOI: 10.1039/C8NR00571K
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“Multi-functional MnO2nanomaterials for photo-activated applications by a plasma-assisted fabrication route”. Barreca D, Gri F, Gasparotto A, Carraro G, Bigiani L, Altantzis T, Žener B, Lavrenčič, Štangar U, Alessi B, Padmanaban DB, Mariotti D, Maccato C, Nanoscale 11, 98 (2019). http://doi.org/10.1039/C8NR06468G
Abstract: Supported MnO2-based nanomaterials were fabricated on fluorine-doped tin oxide substrates by plasma enhanced-chemical vapor deposition (PE-CVD) between 100 °C and 400 °C, starting from a fluorinated Mn(II) diamine diketonate precursor. Growth experiments yielded -MnO2 nanosystems with hierarchical morphology tuneable from dendritic structures to quasi-1D nanosystems as a function of growth temperature, whose variation enabled also a concomitant tailoring of the system fluorine content, and of the optical absorption and band gap. Preliminary photocatalytic tests were aimed at the investigation of photoinduced hydrophilic (PH) and solid phase photocatalytic (PC) performances of the present nanomaterials, as well as at the photodegradation of Plasmocorinth B azo-dye aqueous solutions. The obtained findings highlighted an attractive system photoactivity even under visible light, finely tailored by fluorine content, morphological organization and optical properties of the prepared nanostructures. The results indicate that the synthesized MnO2 nanosystems have potential applications as advanced smart materials for anti-fogging/self-cleaning end uses and water purification.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 7
DOI: 10.1039/C8NR06468G
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“3D characterization of heat-induced morphological changes of Au nanostars by fast in situ electron tomography”. Vanrompay H, Bladt E, Albrecht W, Béché, A, Zakhozheva M, Sánchez-Iglesias A, Liz-Marzán LM, Bals S, Nanoscale 10, 22792 (2018). http://doi.org/10.1039/C8NR08376B
Abstract: A thorough understanding of the thermal stability and potential reshaping of anisotropic gold nanostars is required for various potential applications. Combination of a tomographic heating holder with fast tilt series acquisition has been used to monitor temperature-induced morphological changes of Au nanostars. The outcome of our 3D investigations can be used as an input for boundary element method simulations, enabling us to investigate the influence of reshaping on the nanostars’ plasmonic properties. Our work leads to a better understanding of the mechanism behind thermal reshaping. In addition, the approach presented here is generic and can hence be applied to a wide variety of nanoparticles made of different materials and with arbitrary morphology.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 55
DOI: 10.1039/C8NR08376B
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“Films of filled single-wall carbon nanotubes as a new material for high-performance air-sustainable transparent conductive electrodes operating in a wide spectral range”. Tonkikh AA, Tsebro VI, Obraztsova EA, Rybkovskiy DV, Orekhov AS, Kondrashov II, Kauppinen EI, Chuvilin AL, Obraztsova ED, Nanoscale 11, 6755 (2019). http://doi.org/10.1039/C8NR10238D
Abstract: In this paper we show the advantages of transparent high conductive films based on filled single-wall carbon nanotubes. The nanotubes with internal channels filled with acceptor molecules (copper chloride or iodine) form networks demonstrating significantly improved characteristics. Due to the charge transfer between the nanotubes and filler, the doped-nanotube films exhibit a drop in electrical sheet resistance of an order of magnitude together with a noticeable increase of film transparency in the visible and near-infrared spectral range. The thermoelectric power measurements show a significant improvement of air-stability of the nanotube network in the course of the filling procedure. For the nanotube films with an initial transparency of 87% at 514 nm and electrical sheet resistance of 862 Ohm sq(-1) we observed an improvement of transparency up to 91% and a decrease of sheet resistance down to 98 Ohm sq(-1). The combination of the nanotube synthesis technique and molecules for encapsulation has been optimized for applications in optoelectronics.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 2
DOI: 10.1039/C8NR10238D
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“High-performance supercabatteries using graphite@diamond nano-needle capacitor electrodes and redox electrolytes”. Yu S, Sankaran KJ, Korneychuk S, Verbeeck J, Haenen K, Jiang X, Yang N, Nanoscale 11, 17939 (2019). http://doi.org/10.1039/C9NR07037K
Abstract: Supercabatteries have the characteristics of supercapacitors and batteries, namely high power and energy densities as well as long cycle life. To construct them, capacitor electrodes with wide potential windows and/or redox electrolytes are required. Herein, graphite@diamond nano-needles and an aqueous solution of Fe(CN)(6)(3-/4-) are utilized as the capacitor electrode and the electrolyte, respectively. This diamond capacitor electrode has a nitrogen-doped diamond core and a nano-graphitic shell. In 0.05 M Fe(CN)(6)(3-/4-) + 1.0 M Na2SO4 aqueous solution, the fabricated supercabattery has a capacitance of 66.65 mF cm(-2) at a scan rate of 10 mV s(-1). It is stable over 10 000 charge/discharge cycles. The symmetric supercabattery device assembled using a two-electrode system possesses energy and power densities of 10.40 W h kg(-1) and 6.96 kW kg(-1), respectively. These values are comparable to those of other energy storage devices. Therefore, diamond supercabatteries are promising for many industrial applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 26
DOI: 10.1039/C9NR07037K
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“Transformations of supported gold nanoparticles observed by in situ electron microscopy”. Liu P, Wu T, Madsen J, Schiotz J, Wagner JB, Hansen TW, Nanoscale 11, 11885 (2019). http://doi.org/10.1039/C9NR02731A
Abstract: Oxide supported metal nanoparticles play an important role in heterogeneous catalysis. However, understanding the metal/oxide interface and their evolution under reaction conditions remains challenging. Herein, we investigate the interface between Au nanoparticles and a CeO2 substrate by environmental transmission electron microscopy with atomic resolution. We find that the Au nanoparticles have two preferential epitaxial relationships with the substrate, i.e. Type I (111)[-110]CeO2//(111)[-110]Au and Type II (111)[-110]CeO2//(111)[1-10]Au orientation relationships, where Type I is preferred. In situ observations in the presence of O-2 show that the gas can stimulate the supported Au nanoparticles to transform between these two orientations even at room temperature. Moreover, when increasing the temperature to 973 K, the transformation of an Au nanoparticle between the two orientation states and a non-crystalline state in the presence of O-2 is also observed. DFT calculations of the binding between Au and CeO2 in the two relationships are strongly influenced by the presence of oxygen vacancies. For a given position of a vacancy, there is a significant energy difference between the energy of the two types. However, for some positions, Type I is preferred, and for others, Type II, but the most favourable position of the vacancy for the two types has a very similar energy. This is consistent with the observation of both types of adhesion.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 1
DOI: 10.1039/C9NR02731A
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“Three-dimensional atomic structure of supported Au nanoparticles at high temperature”. Liu P, Arslan Irmak E, De Backer A, De wael A, Lobato I, Béché, A, Van Aert S, Bals S, Nanoscale 13 (2021). http://doi.org/10.1039/D0NR08664A
Abstract: Au nanoparticles (NPs) deposited on CeO2 are extensively used as thermal catalysts since the morphology of the NPs is expected to be stable at elevated temperatures. Although it is well known that the activity of Au NPs depends on their size and surface structure, their three-dimensional (3D) structure at the atomic scale has not been completely characterized as a function of temperature. In this paper, we overcome the limitations of conventional electron tomography by combining atom counting applied to aberration-corrected scanning transmission electron microscopy images and molecular dynamics relaxation. In this manner, we are able to perform an atomic resolution 3D investigation of supported Au NPs. Our results enable us to characterize the 3D equilibrium structure of single NPs as a function of temperature. Moreover, the dynamic 3D structural evolution of the NPs at high temperatures, including surface layer jumping and crystalline transformations, has been studied.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 13
DOI: 10.1039/D0NR08664A
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“Spherical core–shell alumina support particles for model platinum catalysts”. Geerts L, Geerts-Claes H, Skorikov A, Vermeersch J, Vanbutsele G, Galvita V, Constales D, Chandran CV, Radhakrishnan S, Seo JW, Breynaert E, Bals S, Sree SP, Martens JA, Nanoscale 13, 4221 (2021). http://doi.org/10.1039/D0NR08456E
Abstract: γ- and δ-alumina are popular catalyst support materials. Using a hydrothermal synthesis method starting from aluminum nitrate and urea in diluted solution, spherical core–shell particles with a uniform particle size of about 1 μm were synthesized. Upon calcination at 1000 °C, the particles adopted a core–shell structure with a γ-alumina core and δ-alumina shell as evidenced by 2D and 3D electron microscopy and<sup>27</sup>Al magic angle spinning nuclear magnetic resonance spectroscopy. The spherical alumina particles were loaded with Pt nanoparticles with an average size below 1 nm using the strong electrostatic adsorption method. Electron microscopy and energy dispersive X-ray spectroscopy revealed a homogeneous platinum dispersion over the alumina surface. These platinum loaded alumina spheres were used as a model catalyst for bifunctional catalysis. Physical mixtures of Pt/alumina spheres and spherical zeolite particles are equivalent to catalysts with platinum deposited on the zeolite itself facilitating the investigation of the catalyst components individually. The spherical alumina particles are very convenient supports for obtaining a homogeneous distribution of highly dispersed platinum nanoparticles. Obtaining such a small Pt particle size is challenging on other support materials such as zeolites. The here reported and well-characterized Pt/alumina spheres can be combined with any zeolite and used as a bifunctional model catalyst. This is an interesting strategy for the examination of the acid catalytic function without the interference of the supported platinum metal on the investigated acid material.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 3
DOI: 10.1039/D0NR08456E
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“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
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“Stabilization effects in binary colloidal Cu and Ag nanoparticle electrodes under electrochemical CO₂, reduction conditions”. Wu L, Kolmeijer KE, Zhang Y, An H, Arnouts S, Bals S, Altantzis T, Hofmann JP, Costa Figueiredo M, Hensen EJM, Weckhuysen BM, van der Stam W, Nanoscale 13, 4835 (2021). http://doi.org/10.1039/D0NR09040A
Abstract: Nanoparticle modified electrodes constitute an attractive way to tailor-make efficient carbon dioxide (CO2) reduction catalysts. However, the restructuring and sintering processes of nanoparticles under electrochemical reaction conditions not only impedes the widespread application of nanoparticle catalysts, but also misleads the interpretation of the selectivity of the nanocatalysts. Here, we colloidally synthesized metallic copper (Cu) and silver (Ag) nanoparticles with a narrow size distribution (<10%) and utilized them in electrochemical CO2 reduction reactions. Monometallic Cu and Ag nanoparticle electrodes showed severe nanoparticle sintering already at low overpotential of -0.8 V vs. RHE, as evidenced by ex situ SEM investigations, and potential-dependent variations in product selectivity that resemble bulk Cu (14% for ethylene at -1.3 V vs. RHE) and Ag (69% for carbon monoxide at -1.0 V vs. RHE). However, by co-deposition of Cu and Ag nanoparticles, a nanoparticle stabilization effect was observed between Cu and Ag, and the sintering process was greatly suppressed at CO2 reducing potentials (-0.8 V vs. RHE). Furthermore, by varying the Cu/Ag nanoparticle ratio, the CO2 reduction reaction (CO2RR) selectivity towards methane (maximum of 20.6% for dense Cu-2.5-Ag-1 electrodes) and C-2 products (maximum of 15.7% for dense Cu-1-Ag-1 electrodes) can be tuned, which is attributed to a synergistic effect between neighbouring Ag and Cu nanoparticles. We attribute the stabilization of the nanoparticles to the positive enthalpies of Cu-Ag solid solutions, which prevents the dissolution-redeposition induced particle growth under CO2RR conditions. The observed nanoparticle stabilization effect enables the design and fabrication of active CO2 reduction nanocatalysts with high durability.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Impact Factor: 7.367
Times cited: 24
DOI: 10.1039/D0NR09040A
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“Deep learning-based denoising for improved dose efficiency in EDX tomography of nanoparticles”. Skorikov A, Heyvaert W, Albecht W, Pelt DM, Bals S, Nanoscale 13, 12242 (2021). http://doi.org/10.1039/D1NR03232A
Abstract: The combination of energy-dispersive X-ray spectroscopy (EDX) and electron tomography is a powerful approach to retrieve the 3D elemental distribution in nanomaterials, providing an unprecedented level of information for complex, multi-component systems, such as semiconductor devices, as well as catalytic and plasmonic nanoparticles. Unfortunately, the applicability of EDX tomography is severely limited because of extremely long acquisition times and high electron irradiation doses required to obtain 3D EDX reconstructions with an adequate signal-to-noise ratio. One possibility to address this limitation is intelligent denoising of experimental data using prior expectations about the objects of interest. Herein, this approach is followed using the deep learning methodology, which currently demonstrates state-of-the-art performance for an increasing number of data processing problems. Design choices for the denoising approach and training data are discussed with a focus on nanoparticle-like objects and extremely noisy signals typical for EDX experiments. Quantitative analysis of the proposed method demonstrates its significantly enhanced performance in comparison to classical denoising approaches. This allows for improving the tradeoff between the reconstruction quality, acquisition time and radiation dose for EDX tomography. The proposed method is therefore especially beneficial for the 3D EDX investigation of electron beam-sensitive materials and studies of nanoparticle transformations.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 11
DOI: 10.1039/D1NR03232A
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“Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters”. Pramanik G, Kvakova K, Thottappali MA, Rais D, Pfleger J, Greben M, El-Zoka A, Bals S, Dracinsky M, Valenta J, Cigler P, Nanoscale 12, 10462 (2021). http://doi.org/10.1039/D1NR90138A
Abstract: Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin-orbit coupling, which in turn shortens the fluorescence decay lifetime (tau(PL)). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased tau(PL) upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in tau(PL) is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.367
Times cited: 1
DOI: 10.1039/D1NR90138A
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“Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters”. Pramanik G, Kvakova K, Thottappali MA, Rais D, Pfleger J, Greben M, El-Zoka A, Bals S, Dracinsky M, Valenta J, Cigler P, Nanoscale 13, 10462 (2021). http://doi.org/10.1039/D1NR02440J
Abstract: Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin–orbit coupling, which in turn shortens the fluorescence decay lifetime (<italic>τ</italic><sup>PL</sup>). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased<italic>τ</italic><sup>PL</sup>upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine. The heavy atom-mediated increase in<italic>τ</italic><sup>PL</sup>is in striking contrast with the HAE and referred to as inverse HAE. Femtosecond and nanosecond transient absorption spectroscopy revealed overcompensation of a slight decrease in lifetime of the transition associated with the Au core (ps) by a large increase in the long-lived triplet state lifetime associated with the Au shell, which contributed to the observed inverse HAE. This unique observation of inverse HAE in gold nanoclusters provides the means to enhance the triplet excited state lifetime.
Keywords: A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 7.367
Times cited: 7
DOI: 10.1039/D1NR02440J
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“Interface-dependent phononic and optical properties of GeO/MoSO heterostructures”. Yagmurcukardes M, Sozen Y, Baskurt M, Peeters FM, Sahin H, Nanoscale (2021). http://doi.org/10.1039/D1NR06534C
Abstract: The interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G(0)W(0) approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low- and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 7.367
Times cited: 5
DOI: 10.1039/D1NR06534C
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“Vibrational properties of silicene and germanene”. Scalise E, Houssa M, Pourtois G, van den Broek B, Afanas'ev V, Stesmans A, Nano Research 6, 19 (2013). http://doi.org/10.1007/s12274-012-0277-3
Abstract: The structural and vibrational properties of two-dimensional hexagonal silicon (silicene) and germanium (germanene) are investigated by means of first-principles calculations. It is predict that the silicene (germanene) structure with a small buckling of 0.44 (0.7 ) and bond lengths of 2.28 (2.44 ) is energetically the most favorable, and it does not exhibit imaginary phonon mode. The calculated non-resonance Raman spectra of silicene is characterized by a main peak at about 575 cm(-1), namely the G-like peak. For germanene, the highest peak is at about 290 cm(-1). Extensive calculations on armchair silicene nanoribbons and armchair germanene nanoribbons are also performed, with and without hydrogenation of the edges. The studies reveal other Raman peaks mainly distributed at lower frequencies than the G-like peak which could be attributed to the defects at the edges of the ribbons, thus not present in the Raman spectra of non-defective silicene and germanene. Particularly the Raman peak corresponding to the D mode is found to be located at around 515 cm(-1) for silicene and 270 cm(-1) for germanene. The calculated G-like and the D peaks are likely the fingerprints of the Raman spectra of the low-buckled structures of silicene and germanene.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.354
Times cited: 105
DOI: 10.1007/s12274-012-0277-3
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“Strain-induced semiconductor to metal transition in the two-dimensional honeycomb structure of MoS2”. Scalise E, Houssa M, Pourtois G, Afanas'ev V, Stesmans A, Nano Research 5, 43 (2012). http://doi.org/10.1007/s12274-011-0183-0
Abstract: The electronic properties of two-dimensional honeycomb structures of molybdenum disulfide (MoS(2)) subjected to biaxial strain have been investigated using first-principles calculations based on density functional theory. On applying compressive or tensile bi-axial strain on bi-layer and mono-layer MoS(2), the electronic properties are predicted to change from semiconducting to metallic. These changes present very interesting possibilities for engineering the electronic properties of two-dimensional structures of MoS(2).
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.354
Times cited: 407
DOI: 10.1007/s12274-011-0183-0
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“Silicene nanoribbons on transition metal dichalcogenide substrates : effects on electronic structure and ballistic transport”. van den Broek B, Houssa M, Lu A, Pourtois G, Afanas'ev V, Stesmans A, Nano Research 9, 3394 (2016). http://doi.org/10.1007/S12274-016-1217-4
Abstract: The idea of stacking multiple monolayers of different two-dimensional materials has become a global pursuit. In this work, a silicene armchair nanoribbon of width W and van der Waals-bonded to different transition-metal dichalcogenide (TMD) bilayer substrates MoX2 and WX2, where X = S, Se, Te is considered. The orbital resolved electronic structure and ballistic transport properties of these systems are simulated by employing van der Waals-corrected density functional theory and nonequilibrium Green's functions. We find that the lattice mismatch with the underlying substrate determines the electronic structure, correlated with the silicene buckling distortion and ultimately with the contact resistance of the two-terminal system. The smallest lattice mismatch, obtained with the MoTe2 substrate, results in the silicene ribbon properties coming close to those of a freestanding one. With the TMD bilayer acting as a dielectric layer, the electronic structure is tunable from a direct to an indirect semiconducting layer, and subsequently to a metallic electronic dispersion layer, with a moderate applied perpendicular electric field.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.354
Times cited: 2
DOI: 10.1007/S12274-016-1217-4
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“Gallium bismuth halide GaBi-X2 (X = I, Br, Cl) monolayers with distorted hexagonal framework: Novel room-temperature quantum spin Hall insulators”. Li L, Leenaerts O, Kong X, Chen X, Zhao M, Peeters FM, Nano Research 10, 2168 (2017). http://doi.org/10.1007/S12274-017-1464-Z
Abstract: Quantum spin Hall (QSH) insulators with a large topologically nontrivial bulk gap are crucial for future applications of the QSH effect. Among these, group III-V monolayers and their halides, which have a chair structure (regular hexagonal framework), have been widely studied. Using first-principles calculations, we formulate a new structure model for the functionalized group III-V monolayers, which consist of rectangular GaBi-X-2 (X = I, Br, Cl) monolayers with a distorted hexagonal framework (DHF). These structures have a far lower energy than the GaBi-X-2 monolayers with a chair structure. Remarkably, the DHF GaBi-X-2 monolayers are all QSH insulators, which exhibit sizeable nontrivial band gaps ranging from 0.17 to 0.39 eV. The band gaps can be widely tuned by applying different spin-orbit coupling strengths, resulting in a distorted Dirac cone.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 7.354
Times cited: 15
DOI: 10.1007/S12274-017-1464-Z
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“Two-in-one solution using insect wings to produce graphene-graphite films for efficient electrocatalysis”. Li H, Zhang L, Li L, Wu C, Huo Y, Chen Y, Liu X, Ke X, Luo J, Van Tendeloo G, Nano Research 12, 33 (2019). http://doi.org/10.1007/S12274-018-2172-Z
Abstract: Natural organisms contain rich elements and naturally optimized smart structures, both of which have inspired various innovative concepts and designs in human society. In particular, several natural organisms have been used as element sources to synthesize low-cost and environmentally friendly electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells and metal-air batteries, which are clean energy devices. However, to date, no naturally optimized smart structures have been employed in the synthesis of ORR catalysts, including graphene-based materials. Here, we demonstrate a novel strategy to synthesize graphene-graphite films (GGFs) by heating butterfly wings coated with FeCl3 in N-2, in which the full power of natural organisms is utilized. The wings work not only as an element source for GGF generation but also as a porous supporting structure for effective nitrogen doping, two-dimensional spreading, and double-face exposure of the GGFs. These GGFs exhibit a half-wave potential of 0.942 V and a H2O2 yield of < 0.07% for ORR electrocatalysis; these values are comparable to those for the best commercial Pt/C and all previously reported ORR catalysts in alkaline media. This two-in-one strategy is also successful with cicada and dragonfly wings, indicating that it is a universal, green, and cost-effective method for developing high-performance graphene-based materials.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.354
Times cited: 7
DOI: 10.1007/S12274-018-2172-Z
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“Sustainable formation of tricarballylic acid from citric acid over highly stable Pd/Nb2O5.nH2O catalysts”. Stuyck W, Bugaev AL, Nelis T, de Oliveira-Silva R, Smolders S, Usoltsev OA, Arenas Esteban D, Bals S, Sakellariou D, De Vos D, Journal of catalysis (2022). http://doi.org/10.1016/j.jcat.2022.02.013
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 7.3
Times cited: 5
DOI: 10.1016/j.jcat.2022.02.013
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“Can endohedral transition metals enhance hydrogen storage in carbon nanotubes?”.Khalilov U, Uljayev U, Mehmonov K, Nematollahi P, Yusupov M, Neyts EC, Neyts EC, International journal of hydrogen energy 55, 640 (2024). http://doi.org/10.1016/J.IJHYDENE.2023.11.195
Abstract: The safe and efficient use of hydrogen energy, which is in high demand worldwide today, requires efficient hydrogen storage. Despite significant advances in hydrogen storage using carbon-based nanomaterials, including carbon nanotubes (CNTs), efforts to substantially increase the storage capacity remain less effective. In this work, we demonstrate the effect of endohedral transition metal atoms on the hydrogen storage capacity of CNTs using reactive molecular dynamics simulations. We find that an increase in the volume fraction of endohedral nickel atoms leads to an increase in the concentration of physisorbed hydrogen molecules around single-walled CNTs (SWNTs) by approximately 1.6 times compared to pure SWNTs. The obtained results provide insight into the underlying mechanisms of how endohedral transition metal atoms enhance the hydrogen storage ability of SWNTs under nearly ambient conditions.
Keywords: A1 Journal article; Engineering sciences. Technology; Modelling and Simulation in Chemistry (MOSAIC); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.2
DOI: 10.1016/J.IJHYDENE.2023.11.195
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“Intensified swirling reactor for the dehydrogenation of LOHC”. Van Hoecke L, Kummamuru NB, Pourfallah H, Verbruggen SW, Perreault P, International journal of hydrogen energy , 1 (2023). http://doi.org/10.1016/J.IJHYDENE.2023.08.150
Abstract: In the recent advances towards more sustainable global energy supply, H2 is a possible alternative for large scale energy storage. In this view, Liquid Organic Hydrogen Carriers (LOHC) are a class of molecules that allow for easier long term energy storage compared to conventional H2 technologies. CFD simulations were used to showcase the hydrodynamics of the dehydrogenation of a LOHC in a new reactor unit, via a cold flow mock-up study. This reactor was designed to allow for a swirling motion of the liquid carrier material, favouring the removal of H2 gas from the flow and forcing the equilibrium of the reaction towards dehydrogenation, as well as to keep the catalyst particles in motion. The CFD simulations were validated qualitatively with experimental operation of the reactor, in a system with identical dimensionless numbers (Reynolds and Stokes), in order to use less costly products during the prototyping phase.
Keywords: A1 Journal article; Engineering sciences. Technology
Impact Factor: 7.2
DOI: 10.1016/J.IJHYDENE.2023.08.150
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“Eliciting policymakers&rsquo, preferences for technologies to decarbonise transport: A discrete choice experiment”. Bjørnåvold A, Lizin S, Van Dael M, Arnold F, Van Passel S, Environmental Innovation and Societal Transitions 35, 21 (2020). http://doi.org/10.1016/j.eist.2019.12.002
Abstract: Socio-technical transitions are often hindered by the resilience of existing infrastructures, as policymakers are reluctant to invest in novel products or services. Using the example of carbon capture and utilisation (CCU) based fuels, we set up a discrete choice experiment to assess whether European policymakers have a tendency to avoid investing in novel, and more disruptive technologies, and rather prefer to invest in technologies that resemble the incumbent. Results indicate that policymakers prefer to allocate funding to dominant technologies. The results also revealed an overall positive perception of CCU technologies among policymakers. As the commercialisation of such products and processes continues, acceptance among this group of stakeholders is key.
Keywords: A1 Journal Article; Engineering Management (ENM) ;
Impact Factor: 7.2
DOI: 10.1016/j.eist.2019.12.002
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“Validation of computational fluid dynamics in CT-based airway models with SPECT/CT1”. de Backer JW, Vos WG, Vinchurkar SC, Claes R, Drollmann A, Wulfrank D, Parizel PM, Germonpré, P, de Backer W, Radiology 257, 854 (2010). http://doi.org/10.1148/radiol.10100322
Abstract: Purpose: To compare the results obtained by using numerical flow simulations with the results of combined single photon emission computed tomography (SPECT) and computed tomography (CT) and to demonstrate the importance of correct boundary conditions for the numerical methods to account for the large amount of interpatient variability in airway geometry. Materials and Methods: This study was approved by all relevant institutional review boards. All patients gave their signed informed consent. In this study, six patients with mild asthma (three men; three women; overall mean age, 46 years ± 17 [standard deviation]) underwent CT at functional residual capacity and total lung capacity, as well as SPECT/CT. CT data were used for segmentation and computational fluid dynamics (CFD) simulations. A comparison was made between airflow distribution, as derived with (a) SPECT/CT through tracer concentration analysis, (b) CT through lobar expansion measurement, and (c) CFD through flow computer simulation. Also, the heterogeneity of the ventilation was examined. Results: Good agreement was found between SPECT/CT, CT, and CFD in terms of airflow distribution and hot spot detection. The average difference for the internal airflow distribution was less than 3% for CFD and CT versus SPECT/CT. Heterogeneity in ventilation patterns could be detected with SPECT/CT and CFD. Conclusion: This results of this study show that patient-specific computer simulations with appropriate boundary conditions yield information that is similar to that obtained with functional imaging tools, such as SPECT/CT.
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)
Impact Factor: 7.296
Times cited: 100
DOI: 10.1148/radiol.10100322
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“Carbon dioxide splitting in a dielectric barrier discharge plasma : a combined experimental and computational study”. Aerts R, Somers W, Bogaerts A, Chemsuschem 8, 702 (2015). http://doi.org/10.1002/cssc.201402818
Abstract: Plasma technology is gaining increasing interest for the splitting of CO2 into CO and O2. We have performed experiments to study this process in a dielectric barrier discharge (DBD) plasma with a wide range of parameters. The frequency and dielectric material did not affect the CO2 conversion and energy efficiency, but the discharge gap can have a considerable effect. The specific energy input has the most important effect on the CO2 conversion and energy efficiency. We have also presented a plasma chemistry model for CO2 splitting, which shows reasonable agreement with the experimental conversion and energy efficiency. This model is used to elucidate the critical reactions that are mostly responsible for the CO2 conversion. Finally, we have compared our results with other CO2 splitting techniques and we identified the limitations as well as the benefits and future possibilities in terms of modifications of DBD plasmas for greenhouse gas conversion in general.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 7.226
Times cited: 131
DOI: 10.1002/cssc.201402818
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“Selective nickel-catalyzed conversion of model and lignin-derived phenolic compounds to cyclohexanone-based polymer building blocks”. Schutyser W, Van den Bosch S, Dijkmans J, Turner S, Meledina M, Van Tendeloo G, Debecker DP, Sels BF, Chemsuschem 8, 1805 (2015). http://doi.org/10.1002/cssc.201403375
Abstract: Valorization of lignin is essential for the economics of future lignocellulosic biorefineries. Lignin is converted into novel polymer building blocks through four steps: catalytic hydroprocessing of softwood to form 4-alkylguaiacols, their conversion into 4-alkylcyclohexanols, followed by dehydrogenation to form cyclohexanones, and Baeyer-Villiger oxidation to give caprolactones. The formation of alkylated cyclohexanols is one of the most difficult steps in the series. A liquid-phase process in the presence of nickel on CeO2 or ZrO2 catalysts is demonstrated herein to give the highest cyclohexanol yields. The catalytic reaction with 4-alkylguaiacols follows two parallel pathways with comparable rates: 1) ring hydrogenation with the formation of the corresponding alkylated 2-methoxycyclohexanol, and 2) demethoxylation to form 4-alkylphenol. Although subsequent phenol to cyclohexanol conversion is fast, the rate is limited for the removal of the methoxy group from 2-methoxycyclohexanol. Overall, this last reaction is the rate-limiting step and requires a sufficient temperature (> 250 degrees C) to overcome the energy barrier. Substrate reactivity (with respect to the type of alkyl chain) and details of the catalyst properties (nickel loading and nickel particle size) on the reaction rates are reported in detail for the Ni/CeO2 catalyst. The best Ni/CeO2 catalyst reaches 4-alkylcyclohexanol yields over 80 %, is even able to convert real softwood-derived guaiacol mixtures and can be reused in subsequent experiments. A proof of principle of the projected cascade conversion of lignocellulose feedstock entirely into caprolactone is demonstrated by using Cu/ZrO2 for the dehydrogenation step to produce the resultant cyclohexanones (approximate to 80%) and tin-containing beta zeolite to form 4-alkyl-e-caprolactones in high yields, according to a Baeyer-Villiger-type oxidation with H2O2.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 7.226
Times cited: 71
DOI: 10.1002/cssc.201403375
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“Design of Ru-zeolites for hydrogen-free production of conjugated linoleic acid”. Philippaerts A, Goossens S, Vermandel W, Tromp M, Turner S, Geboers J, Van Tendeloo G, Jacobs PA, Sels BF, Chemsuschem 4, 757 (2011). http://doi.org/10.1002/cssc.201100015
Abstract: While conjugated vegetable oils are currently used as additives in the drying agents of oils and paints, they are also attractive molecules for making bio-plastics. Moreover, conjugated oils will soon be accepted as nutritional additives for functional food products. While current manufacture of conjugated vegetable oils or conjugated linoleic acids (CLAs) uses a homogeneous base as isomerisation catalyst, a heterogeneous alternative is not available today. This contribution presents the direct production of CLAs over Ru supported on different zeolites, varying in topology (ZSM-5, BETA, Y), Si/Al ratio and countercation (H+, Na+, Cs+). Ru/Cs-USY, with a Si/Al ratio of 40, was identified as the most active and selective catalyst for isomerisation of methyl linoleate (cis-9,cis-12 (C18:2)) to CLA at 165 °C. Interestingly, no hydrogen pre-treatment of the catalyst or addition of hydrogen donors is required to achieve industrially relevant isomerisation productivities, namely, 0.7 g of CLA per litre of solvent per minute. Moreover, the biologically most active CLA isomers, namely, cis-9,trans-11, trans-10,cis-12 and trans-9,trans-11, were the main products, especially at low catalyst concentrations. Ex situ physicochemical characterisation with CO chemisorption, extended X-ray absorption fine structure measurements, transmission electron microscopy analysis, and temperature-programmed oxidation reveals the presence of highly dispersed RuO2 species in Ru/Cs-USY(40).
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 7.226
Times cited: 24
DOI: 10.1002/cssc.201100015
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“Multimodal zeolite-beta-based catalysts with a hierarchical, three-level pore structure”. Chen L-H, Li X-Y, Tian G, Li Y, Tan H-Y, Van Tendeloo G, Zhu G-S, Qiu S-L, Yang X-Y, Su B-L, Chemsuschem 4, 1452 (2011). http://doi.org/10.1002/cssc.201100181
Abstract: Hole diggers: The hierarchically structured porous solid-acid catalyst described in this report possess a remarkable pore system, encompassing well-defined macrochannels, interconnected mesopores, intracrystalline mesopores, and tunable zeolite micropores. Importantly, the catalyst exhibits very strong acidity and superior catalytic activity for esterification reactions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 7.226
Times cited: 33
DOI: 10.1002/cssc.201100181
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“A non-aqueous synthesis of TiO2SiO2 composites in supercritical CO2 for the photodegradation of pollutants”. Jammaer J, Aprile C, Verbruggen SW, Lenaerts S, Pescarmona PP, Martens JA, Chemsuschem 4, 1457 (2011). http://doi.org/10.1002/CSSC.201100059
Abstract: Titania/silica composites with different Ti/Si ratios are synthesized via a nonconventional synthesis route. The synthesis involves non-aqueous reaction of metal alkoxides and formic acid at 75 °C in supercritical carbon dioxide. The as-prepared composite materials contain nanometer-sized anatase crystallites and amorphous silica. Large specific surface areas are obtained. The composites are evaluated in the photocatalytic degradation of phenol in aqueous medium, and in the elimination of acetaldehyde from air. The highest photocatalytic activity in both processes is achieved with a composite containing 40 wt % TiO2.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 7.226
Times cited: 15
DOI: 10.1002/CSSC.201100059
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