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“25 years of Reticular Chemistry”. Freund R, Canossa S, Cohen SM, Yan W, Deng H, Guillerm V, Eddaoudi M, Madden DG, Fairen-Jimenez D, Lyu H, Macreadie LK, Ji Z, Zhang Y, Wang B, Haase F, Wöll C, Zaremba O, Andreo J, Wuttke S, Diercks CS, Angewandte Chemie-International Edition , anie.202101644 (2021). http://doi.org/10.1002/anie.202101644
Abstract: At its core, reticular chemistry has translated the precision and expertise of organic and inorganic synthesis to the solid state. While initial excitement over metal‐organic frameworks (MOFs) and covalent organic frameworks (COFs) was undoubtedly fueled by their unprecedented porosity and surface areas, the most profound scientific innovation of the field has been the elaboration of design strategies for the synthesis of extended crystalline solids through strong directional bonds. In this contribution we highlight the different classes of reticular materials that have been developed, how these frameworks can be functionalized and how complexity can be introduced into their backbones. Finally, we show how the structural control over these materials is being extended from the molecular scale to their crystal morphology and shape on the nanoscale, all the way to their shaping on the bulk scale.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 11.994
DOI: 10.1002/anie.202101644
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“2D quantum materials : magnetism and superconductivity”. Milošević, MV, Mandrus D, Journal Of Applied Physics 130, 180401 (2021). http://doi.org/10.1063/5.0075774
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.068
DOI: 10.1063/5.0075774
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“3D Atomic Structure of Supported Metallic Nanoparticles Estimated from 2D ADF STEM Images: A Combination of Atom –, Counting and a Local Minima Search Algorithm”. Arslan Irmak E, Liu P, Bals S, Van Aert S, Small methods , 2101150 (2021). http://doi.org/10.1002/smtd.202101150
Abstract: Determining the three-dimensional (3D) atomic structure of nanoparticles (NPs) is critical to understand their structure-dependent properties. It is hereby important to perform such analyses under conditions relevant for the envisioned application. Here, we investigate the 3D structure of supported Au NPs at high temperature, which is of importance to understand their behavior during catalytic reactions. To overcome limitations related to conventional high-resolution electron tomography at high temperature, 3D characterization of NPs with atomic resolution has been performed by applying atom-counting using atomic resolution annular darkfield scanning transmission electron microscopy (ADF STEM) images followed by structural relaxation. However, at high temperatures, thermal displacements, which affect the ADF STEM intensities, should be taken into account. Moreover, it is very likely that the structure of a NP investigated at elevated temperature deviates from a ground state configuration, which is difficult to determine using purely computational energy minimization approaches. In this paper, we therefore propose an optimized approach using an iterative local minima search algorithm followed by molecular dynamics (MD) structural relaxation of candidate structures associated with each local minimum. In this manner, it becomes possible to investigate the 3D atomic structure of supported NPs, which may deviate from their ground state configuration.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Times cited: 12
DOI: 10.1002/smtd.202101150
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“3D Atomic‐Scale Dynamics of Laser‐Light‐Induced Restructuring of Nanoparticles Unraveled by Electron Tomography”. Albrecht W, Arslan Irmak E, Altantzis T, Pedrazo‐Tardajos A, Skorikov A, Deng T‐S, van der Hoeven JES, van Blaaderen A, Van Aert S, Bals S, Advanced Materials , 2100972 (2021). http://doi.org/10.1002/adma.202100972
Abstract: Understanding light–matter interactions in nanomaterials is crucial for
optoelectronic, photonic, and plasmonic applications. Specifically, metal
nanoparticles (NPs) strongly interact with light and can undergo shape
transformations, fragmentation and ablation upon (pulsed) laser excitation.
Despite being vital for technological applications, experimental insight into
the underlying atomistic processes is still lacking due to the complexity of
such measurements. Herein, atomic resolution electron tomography is performed
on the same mesoporous-silica-coated gold nanorod, before and after
femtosecond laser irradiation, to assess the missing information. Combined
with molecular dynamics (MD) simulations based on the experimentally
determined 3D atomic-scale morphology, the complex atomistic rearrangements,
causing shape deformations and defect generation, are unraveled.
These rearrangements are simultaneously driven by surface diffusion, facet
restructuring, and strain formation, and are influenced by subtleties in the
atomic distribution at the surface.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Impact Factor: 19.791
Times cited: 8
DOI: 10.1002/adma.202100972
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“A biobased, bioactive, low CO₂, impact coating for soil improvers”. Wei&beta, R, Gritsch S, Brader G, Nikolic B, Spiller M, Santolin J, Weber HK, Schwaiger N, Pluchon S, Dietel K, Guebitz G, Nyanhongo G, Green Chemistry 23, 6501 (2021). http://doi.org/10.1039/D1GC02221K
Abstract: Lignosulfonate-based bioactive coatings as soil improvers for lawns were developed using laccase as a biocatalyst. Incorporation of glycerol, xylitol and sorbitol as plasticizers considerably reduced the brittleness of the synthesized coatings of marine carbonate granules while thermal enzyme inactivation at 100 degrees C enabled the production of stable coatings. Heat inactivation produced stable coatings with a molecular weight of 2000 kDa and a viscosity of 4.5 x 10(-3) Pas. The desired plasticity for the spray coating of soil improver granules was achieved by the addition of 2.7% of xylitol. Agriculture beneficial microorganisms (four different Bacillus species) were integrated into the coatings. The stable coatings protected the marine calcium carbonate granules, maintained the viability of the microorganisms and showed no toxic effects on the germination and growth of model plants including corn, wheat, salad, and tomato despite a slight delay in germination. Moreover, the coatings reduced the dust formation of soil improvers by 70%. CO2 emission analysis showed potential for the reduction of up to 3.4 kg CO2-eq. kg(-1) product, making it a viable alternative to fossil-based coatings.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 9.125
DOI: 10.1039/D1GC02221K
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“A covalently linked dyad based on zinc phthalocyanine and methylpheophorbide &alpha, : synthetic and physicochemical study”. Balashova IO, Tolbin AY, Tarakanov PA, Krot AR, Fedorova K V, Sergeeva IA, Trashin SA, De Wael K, Pushkarev VE, Koifman MO, Ponomarev G V, Macroheterocycles 14, 40 (2021). http://doi.org/10.6060/MHC210338P
Abstract: The first covalently linked conjugate of metal phthalocyaninate and chlorin e(6) derivative has been obtained by transesterification of alpha-ketomethyl ester in methylpheophorbide a with zinc(II) 2-(2-hydroxymethylbenzyloxy)-9(10),16(17),23(24)-tri-tert-butylphthalocyaninate under mild conditions. The dyad exhibits a panchromatic nature revealing both the phthalocyanine and pheophorbide derived bands in the UV-Vis absorption spectrum. The H-1 NMR spectroscopy data combined with theoretical calculations indicate the presence of spatial intramolecular interactions between the phthalocyanine, pheophorbide and spacer fragments of the dyad allowing to forecast its enhanced nonlinear optical properties, as well as the characteristic energy transfer from the excited pheophorbide subunit to the phthalocyanine core. Indeed, when excited in the UV-Vis range, the conjugate shows red fluorescence with the spectral maximum at 686 nm, which is close to the one of the initial zinc phthalocyaninate. Furthermore, the dyad effectively generates singlet oxygen and, in the presence of polyvinylpyrrolidone (PVP) as biocompatible solubilizer, forms stable micellar saline solutions with the particles ranged in size between 40 and 100 nm. These nanoparticles represent promising third-generation photosensitizing systems for application in theranostics.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.6060/MHC210338P
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“A cross-European analysis of the impact of electricity pricing on battery uptake in residential microgrids with photovoltaic units”. Saviuc I, Milis K, Peremans H, Van Passel S, Journal of Sustainable Development of Energy, Water and Environment Systems 9, 1080368 (2021). http://doi.org/10.13044/J.SDEWES.D8.0368
Abstract: As decentralized electricity generation is supporting grid development into the prosumer era, this paper investigates the economic viability of adding batteries to residential microgrids powered by photovoltaic units, under various electricity pricing schemes. Batteries bring the benefits of grid-stabilization and congestion relief, and they are also becoming cheaper. The problem identified is that the main grid effectively acts as a lossless storage system, especially under the net-metering scheme, whereas using a battery involves investment costs and energy losses. This mismatch is addressed by analysing residential microgrid projects under seven tariff designs, each in seven countries of the European Union, and compare the economic viability of photovoltaic systems with and without batteries. The findings show that the conditions most favourable to batteries are given by a capacity tariff scheme allowing price arbitrage. Based on these findings, the paper discusses possibilities for further support in order to bring the economic viability of microgrids with batteries on par with that of microgrids without batteries.
Keywords: A1 Journal article; Engineering Management (ENM)
DOI: 10.13044/J.SDEWES.D8.0368
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“A database system for querying of river networks : facilitating monitoring and prediction applications”. Bollen E, Pagan BR, Kuijpers B, Van Hoey S, Desmet N, Hendrix R, Dams J, Seuntjens P, Water Science And Technology-Water Supply (2021). http://doi.org/10.2166/WS.2021.433
Abstract: The increasing availability of real-time in situ measurements and remote sensing observations have the potential to contribute to the optimization of water resources management. Global challenges such as climate change, intensive agriculture and urbanization put a high pressure on our water resources. Due to recent innovations in measuring both water quantity and quality, river systems can now be monitored in real time at an unprecedented spatial and temporal scale. To interpret the sensor measurements and remote sensing observations additional data for example on: the location of the measurement, upstream and downstream catchment characteristics, horizontal ellipsis are required. In this paper, we present a data management system to support flow-path related functionality for decision making and prediction modelling. Adding meta data sets and facilitating (near) real-time processing of sensor data questions are key concepts for the systems. The potential of the database framework for hydrological applications is demonstrated using different applications for the river system of Flanders. In one, the database framework is used to simulate the daily discharge for each segment within a catchment using a simple data-driven approach. The presented system is useful for numerous applications including pollution tracking, alerting and inter-sensor validation in river systems, or related networks.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 0.573
DOI: 10.2166/WS.2021.433
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“A Dirac-semimetal two-dimensional BeN4 : thickness-dependent electronic and optical properties”. Bafekry A, Stampfl C, Faraji M, Yagmurcukardes M, Fadlallah MM, Jappor HR, Ghergherehchi M, Feghhi SAH, Applied Physics Letters 118, 203103 (2021). http://doi.org/10.1063/5.0051878
Abstract: Motivated by the recent experimental realization of a two-dimensional (2D) BeN4 monolayer, in this study we investigate the structural, dynamical, electronic, and optical properties of a monolayer and few-layer BeN4 using first-principles calculations. The calculated phonon band dispersion reveals the dynamical stability of a free-standing BeN4 layer, while the cohesive energy indicates the energetic feasibility of the material. Electronic band dispersions show that monolayer BeN4 is a semi-metal whose conduction and valence bands touch each other at the Sigma point. Our results reveal that increasing the layer number from single to six-layers tunes the electronic nature of BeN4. While monolayer and bilayer structures display a semi-metallic behavior, structures thicker than that of three-layers exhibit a metallic nature. Moreover, the optical parameters calculated for monolayer and bilayer structures reveal that the bilayer can absorb visible light in the ultraviolet and visible regions better than the monolayer structure. Our study investigates the electronic properties of Dirac-semimetal BeN4 that can be an important candidate for applications in nanoelectronic and optoelectronic. Published under an exclusive license by AIP Publishing.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.411
DOI: 10.1063/5.0051878
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“A new generalized empirical correlation for predicting methane hydrate equilibrium conditions in pure water”. Kummamuru NB, Perreault P, Lenaerts S, Industrial &, Engineering Chemistry Research 60, 3474 (2021). http://doi.org/10.1021/ACS.IECR.0C05833
Abstract: This work contributes to a new generalized empirical correlation for predicting methane (CH4) hydrate equilibrium conditions in pure water. Unlike the conventional thermodynamic approach that involves complex reckoning, the proposed empirical equation is developed by regressing 215 experimental data points from the literature and validating with 45 data points for predicting methane hydrate equilibrium conditions in pure water. The new correlation is proposed for a temperature and pressure range of 273.2–303.48 K and 2.63–72.26 MPa, respectively. The accuracy and performance of the proposed correlation is quantitatively evaluated using statistical error analysis. The proposed correlation was able to estimate CH4 hydrate equilibrium conditions satisfactorily with an R2 of 0.99987. The overall error analysis for the proposed correlation shows fair agreement with the experimental data reported within the literature. Concurrently, the new correlation showed better performance in predicting equilibrium conditions compared to those calculated by other empirical correlations available in the literature within the investigated range. In addition, the proposed empirical equation is also checked to evaluate its efficacy in fitting each set of experimental binary/ternary methane hydrates (BTMH) and binary hydrogen hydrates (BHH) for an accurate representation of equilibrium data over a wide range of composition, pressure, and temperature conditions. A maximum percentage deviation of 0.58% and 0.24% was observed between experimental and calculated equilibrium conditions for BTMH and BHH, respectively.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 2.843
DOI: 10.1021/ACS.IECR.0C05833
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“A new sulfolane based solvent for CO₂, capture”. Wagaarachchige J, Idris Z, Kummamuru NB, Sætre KA, Halstensen M, Jens K-J, SSRN electronic journal (2021). http://doi.org/10.2139/SSRN.3817192
Abstract: This study presents novel sulfolane based non-aqueous CO2 capture solvents, as an alternative solution for capturing CO2 from industrial processes. In order to select the most promising amine system, five different amines were tested by monitoring CO2 absorption and desorption processes using the time-base Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy. During absorption experiments, we observed the formation of Monomethyl Carbonate (MMC) in diisopropylamine (DIPA) and 2-amino-2-methyl-1-propanol (AMP) systems, while carbamate was observed as the main product for the other three amine systems tested. In regeneration experiments, the MMC could be desorbed relatively easily from the amine solution at a mild temperature.
Keywords: P1 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.2139/SSRN.3817192
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“A review of technological solutions to prevent or reduce marine plastic litter in developing countries”. Winterstetter A, Grodent M, Kini V, Ragaert K, Vrancken KCM, Sustainability 13, 4894 (2021). http://doi.org/10.3390/SU13094894
Abstract: Growing global plastic production combined with poor waste collection has led to increasing amounts of plastic debris being found in oceans, rivers and on shores. The goal of this study is to provide an overview on currently available technological solutions to tackle marine plastic litter and to assess their potential use in developing countries. To compile an inventory of technological solutions, a dedicated online platform was developed. A total of 51 out of initially 75 submitted solutions along the plastics value chain were assessed by independent experts. Collection systems represent more than half of the shortlisted solutions. A quarter include processing and treatment technologies, either as a stand-alone solution (30%) or, more commonly, in combination with a first litter capturing step. Ten percent offer digital solutions. The rest focuses on integrated waste management solutions. For each stage in the source-to-sea spectrum-land, rivers, sea-two illustrative examples are described in detail. This study concludes that the most cost-effective type of solution tackles land-based sources of marine litter and combines technology with people-oriented practices, runs on own energy sources, connects throughout the plastics value chain with a convincing valorization plan for captured debris, and involves all relevant stakeholders.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Impact Factor: 1.789
DOI: 10.3390/SU13094894
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“A simple method to clean ligand contamination on TEM grids”. Li C, Tardajos AP, Wang D, Choukroun D, Van Daele K, Breugelmans T, Bals S, Ultramicroscopy 221, 113195 (2021). http://doi.org/10.1016/j.ultramic.2020.113195
Abstract: Colloidal nanoparticles (NPs) including nanowires and nanosheets made by chemical methods involve many organic ligands. When the structure of NPs is investigated via transmission electron microscopy (TEM), the organic ligands act as a source for e-beam induced deposition and this causes substantial build-up of carbon layers in the investigated areas, which is typically referred to as “contamination” in the eld of electron mi- croscopy. This contamination is often more severe for scanning TEM, a technique that is based on a focused electron beam and hence higher electron dose rate. In this paper, we report a simple and effective method to clean drop-cast TEM grids that contain NPs with ligands. Using a combination of activated carbon and ethanol, this method effectively reduces the amount of ligands on TEM grids, and therefore greatly improves the quality of electron microscopy images and subsequent analytical measurements. This ef cient and facile method can be helpful during electron microscopy investigation of different kinds of nanomaterials that suffer from ligand- induced contamination.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Applied Electrochemistry & Catalysis (ELCAT)
Impact Factor: 2.843
Times cited: 10
DOI: 10.1016/j.ultramic.2020.113195
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“A systematic comparison of commercially produced struvite : quantities, qualities and soil-maize phosphorus availability”. Muys M, Phukan R, Brader G, Samad A, Moretti M, Haiden B, Pluchon S, Roest K, Vlaeminck SE, Spiller M, Science Of The Total Environment 756, 143726 (2021). http://doi.org/10.1016/J.SCITOTENV.2020.143726
Abstract: Production of struvite (MgNH4PO4·6H2O) from waste streams is increasingly implemented to recover phosphorus (P), which is listed as a critical raw material in the European Union (EU). To facilitate EU-wide trade of P-containing secondary raw materials such as struvite, the EU issued a revised fertilizer regulation in 2019. A comprehensive overview of the supply of struvite and its quality is presently missing. This study aimed: i) to determine the current EU struvite production volumes, ii) to evaluate all legislated physicochemical characteristics and pathogen content of European struvite against newly set regulatory limits, and iii) to compare not-regulated struvite characteristics. It is estimated that in 2020, between 990 and 1250 ton P are recovered as struvite in the EU. Struvite from 24 European production plants, accounting for 30% of the 80 struvite installations worldwide was sampled. Three samples failed the physicochemical legal limits; one had a P content of <7% and three exceeded the organic carbon content of 3% dry weight (DW). Mineralogical analysis revealed that six samples had a struvite content of 80–90% DW, and 13 samples a content of >90% DW. All samples showed a heavy metal content below the legal limits. Microbiological analyses indicated that struvite may exceed certain legal limits. Differences in morphology and particle size distribution were observed for struvite sourced from digestate (rod shaped; transparent; 82 mass% < 1 mm), dewatering liquor (spherical; opaque; 65 mass% 1–2 mm) and effluent from upflow anaerobic sludge blanket reactor processing potato wastewater (spherical; opaque; 51 mass% < 1 mm and 34 mass% > 2 mm). A uniform soil-plant P-availability pattern of 3.5–6.5 mg P/L soil/d over a 28 days sampling period was observed. No differences for plant biomass yield were observed. In conclusion, the results highlight the suitability of most struvite to enter the EU fertilizer market.
Keywords: A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Engineering Management (ENM)
Impact Factor: 4.9
DOI: 10.1016/J.SCITOTENV.2020.143726
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“A van der Waals heterostructure of MoS₂/MoSi₂N₄, : a first-principles study”. Bafekry A, Faraji M, Ziabari AA, Fadlallah MM, Nguyen C V, Ghergherehchi M, Feghhi SAH, New Journal Of Chemistry 45, 8291 (2021). http://doi.org/10.1039/D1NJ00344E
Abstract: Motivated by the successful preparation of MoSi2N4 monolayers in the last year [Y.-L. Hong et al., Science, 2020, 369, 670-674], we investigate the structural, electronic and optical properties of the MoS2/MoSi2N4 heterostructure (HTS). The phonon dispersion and the binding energy calculations refer to the stability of the HTS. The heterostructure has an indirect bandgap of 1.26 (1.84) eV using PBE (HSE06) which is smaller than the corresponding value of MoSi2N4 and MoS2 monolayers. We find that the work function of the MoS2/MoSi2N4 HTS is smaller than the corresponding value of its individual monolayers. The heterostructure structure can enhance the absorption of light spectra not only in the ultraviolet region but also in the visible region as compared to MoSi2N4 and MoS2 monolayers. The refractive index behaviour of the HTS can be described as the cumulative effect which is well described in terms of a combination of the individual effects (the refractive index of MoSi2N4 and MoS2 monolayers).
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.269
DOI: 10.1039/D1NJ00344E
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“ab initio description of bonding for transmission electron microscopy”. Madsen J, Pennycook TJ, Susi T, Ultramicroscopy 231 (2021). http://doi.org/10.1016/J.ULTRAMIC.2021.113253
Abstract: The simulation of transmission electron microscopy (TEM) images or diffraction patterns is often required to interpret their contrast and extract specimen features. This is especially true for high-resolution phase-contrast imaging of materials, but electron scattering simulations based on atomistic models are widely used in materials science and structural biology. Since electron scattering is dominated by the nuclear cores, the scattering potential is typically described by the widely applied independent atom model. This approximation is fast and fairly accurate, especially for scanning TEM (STEM) annular dark-field contrast, but it completely neglects valence bonding and its effect on the transmitting electrons. However, an emerging trend in electron microscopy is to use new instrumentation and methods to extract the maximum amount of information from each electron. This is evident in the increasing popularity of techniques such as 4D-STEM combined with ptychography in materials science, and cryogenic microcrystal electron diffraction in structural biology, where subtle differences in the scattering potential may be both measurable and contain additional insights. Thus, there is increasing interest in electron scattering simulations based on electrostatic potentials obtained from first principles, mainly via density functional theory, which was previously mainly required for holography. In this Review, we discuss the motivation and basis for these developments, survey the pioneering work that has been published thus far, and give our outlook for the future. We argue that a physically better justified ab initio description of the scattering potential is both useful and viable for an increasing number of systems, and we expect such simulations to steadily gain in popularity and importance.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
DOI: 10.1016/J.ULTRAMIC.2021.113253
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“Ab initio modeling of few-layer dilute magnetic semiconductors”. Tiwari S, Van de Put ML, Sorée B, Vandenberghe WG, International Conference on Simulation of Semiconductor Processes and Devices : [proceedings]
T2 –, International Conference on Simulation of Semiconductor Processes and, Devices (SISPAD), SEP 27-29, 2021, Dallas, TX , 141 (2021). http://doi.org/10.1109/SISPAD54002.2021.9592535
Abstract: We present a computational model to model the magnetic structure of two-dimensional (2D) dilute-magnetic-semiconductors (DMS) both the monolayers and multilayers using first-principles density functional theory (DFT), as well as their magnetic phase transition as a function of temperature using Monte-Carlo simulations. Using our method, we model the magnetic structure of bulk, bilayer, and monolayer MoS2 substitutionally doped with Fe atoms. We find that the out-of-plane interaction in bilayer MoS2 is weakly ferromagnetic, whereas in bulk MoS2 it is strongly anti-ferromagnetic. Finally, we show that the magnetic order is more robust in bilayer Fe-doped MoS2 compared to the monolayer and results in a room-temperature FM at an atomic substitution of 14-16%.
Keywords: P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT)
DOI: 10.1109/SISPAD54002.2021.9592535
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“Ab initio prediction of semiconductivity in a novel two-dimensional Sb₂X₃, (X= S, Se, Te) monolayers with orthorhombic structure”. Bafekry A, Mortazavi B, Faraji M, Shahrokhi M, Shafique A, Jappor HR, Nguyen C, Ghergherehchi M, Feghhi SAH, Scientific Reports 11, 10366 (2021). http://doi.org/10.1038/S41598-021-89944-4
Abstract: Sb2S3 and Sb2Se3 are well-known layered bulk structures with weak van der Waals interactions. In this work we explore the atomic lattice, dynamical stability, electronic and optical properties of Sb2S3, Sb2Se3 and Sb2Te3 monolayers using the density functional theory simulations. Molecular dynamics and phonon dispersion results show the desirable thermal and dynamical stability of studied nanosheets. On the basis of HSE06 and PBE/GGA functionals, we show that all the considered novel monolayers are semiconductors. Using the HSE06 functional the electronic bandgap of Sb2S3, Sb2Se3 and Sb2Te3 monolayers are predicted to be 2.15, 1.35 and 1.37 eV, respectively. Optical simulations show that the first absorption coefficient peak for Sb2S3, Sb2Se3 and Sb2Te3 monolayers along in-plane polarization is suitable for the absorption of the visible and IR range of light. Interestingly, optically anisotropic character along planar directions can be desirable for polarization-sensitive photodetectors. Furthermore, we systematically investigate the electrical transport properties with combined first-principles and Boltzmann transport theory calculations. At optimal doping concentration, we found the considerable larger power factor values of 2.69, 4.91, and 5.45 for hole-doped Sb2S3, Sb2Se3, and Sb2Te3, respectively. This study highlights the bright prospect for the application of Sb2S3, Sb2Se3 and Sb2Te3 nanosheets in novel electronic, optical and energy conversion systems.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.259
DOI: 10.1038/S41598-021-89944-4
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“Ab-initio study of magnetically intercalated platinum diselenide : the impact of platinum vacancies”. Reyntjens PD, Tiwari S, van de Put ML, Sorée B, Vandenberghe WG, Materials 14, 4167 (2021). http://doi.org/10.3390/MA14154167
Abstract: We study the magnetic properties of platinum diselenide (PtSe2) intercalated with Ti, V, Cr, and Mn, using first-principle density functional theory (DFT) calculations and Monte Carlo (MC) simulations. First, we present the equilibrium position of intercalants in PtSe2 obtained from the DFT calculations. Next, we present the magnetic groundstates for each of the intercalants in PtSe2 along with their critical temperature. We show that Ti intercalants result in an in-plane AFM and out-of-plane FM groundstate, whereas Mn intercalant results in in-plane FM and out-of-plane AFM. V intercalants result in an FM groundstate both in the in-plane and the out-of-plane direction, whereas Cr results in an AFM groundstate both in the in-plane and the out-of-plane direction. We find a critical temperature of <0.01 K, 111 K, 133 K, and 68 K for Ti, V, Cr, and Mn intercalants at a 7.5% intercalation, respectively. In the presence of Pt vacancies, we obtain critical temperatures of 63 K, 32 K, 221 K, and 45 K for Ti, V, Cr, and Mn-intercalated PtSe2, respectively. We show that Pt vacancies can change the magnetic groundstate as well as the critical temperature of intercalated PtSe2, suggesting that the magnetic groundstate in intercalated PtSe2 can be controlled via defect engineering.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 2.654
DOI: 10.3390/MA14154167
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“Abnormal in-plane permittivity and ferroelectricity of confined water : from sub-nanometer channels to bulk”. Hamid I, Jalali H, Peeters FM, Neek-Amal M, Journal Of Chemical Physics 154, 114503 (2021). http://doi.org/10.1063/5.0038359
Abstract: Dielectric properties of nano-confined water are important in several areas of science, i.e., it is relevant in the dielectric double layer that exists in practically all heterogeneous fluid-based systems. Molecular dynamics simulations are used to predict the in-plane dielectric properties of confined water in planar channels of width ranging from sub-nanometer to bulk. Because of suppressed rotational degrees of freedom near the confining walls, the dipole of the water molecules tends to be aligned parallel to the walls, which results in a strongly enhanced in-plane dielectric constant (epsilon (parallel to)) reaching values of about 120 for channels with height 8 angstrom < h < 10 angstrom. With the increase in the width of the channel, we predict that epsilon (parallel to) decreases nonlinearly and reaches the bulk value for h > 70 angstrom. A stratified continuum model is proposed that reproduces the h > 10 angstrom dependence of epsilon (parallel to). For sub-nanometer height channels, abnormal behavior of epsilon (parallel to) is found with two orders of magnitude reduction of epsilon (parallel to) around h similar to 7.5 angstrom, which is attributed to the formation of a particular ice phase that exhibits long-time (similar to mu s) stable ferroelectricity. This is of particular importance for the understanding of the influence of confined water on the functioning of biological systems.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.965
Times cited: 13
DOI: 10.1063/5.0038359
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“Accounting for externalities in cross-sectional economic models of climate change impacts”. Moretti M, Vanschoenwinkel J, Van Passel S, Ecological Economics 185, 107058 (2021). http://doi.org/10.1016/J.ECOLECON.2021.107058
Abstract: Environmental effects and natural resources depletion associated with agriculture production affect the agriculture response to climate change. Traditional cross-sectional climate response models ignore this requirement. This research estimates the impact of climate on European agriculture using a continental scale Ricardian analysis. We correct farm income by accounting for resources (energy, fertilisers, pesticides, and water) use intensity and calculate the sustainable value for a sample of 9497 specialized field crop farms. Compared with the traditional Ricardian method, the marginal effects of temperature remain positive (but less positive) in Northern countries, while it leads to less damages in Southern countries when net revenue and farms? sustainable values are used as dependent variables. Accounting for the environmental effects and depletion of natural capital improves the ability of the Ricardian method to estimate agriculture climate response functions in the long run.
Keywords: A1 Journal article; Economics; Engineering Management (ENM)
Impact Factor: 2.965
DOI: 10.1016/J.ECOLECON.2021.107058
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“Accurate simulations of the reaction of H₂, on a curved Pt crystal through machine learning”. Gerrits N, Journal Of Physical Chemistry Letters 12, 12157 (2021). http://doi.org/10.1021/ACS.JPCLETT.1C03395
Abstract: Theoretical studies on molecule-metal surface reactions have so far been limited to small surface unit cells due to computational costs. Here, for the first time molecular dynamics simulations on very large surface unit cells at the level of density functional theory are performed, allowing a direct comparison to experiments performed on a curved crystal. Specifically, the reaction of D-2 on a curved Pt crystal is investigated with a neural network potential (NNP). The developed NNP is also accurate for surface unit cells considerably larger than those that have been included in the training data, allowing dynamical simulations on very large surface unit cells that otherwise would have been intractable. Important and complex aspects of the reaction mechanism are discovered such as diffusion and a shadow effect of the step. Furthermore, conclusions from simulations on smaller surface unit cells cannot always be transfered to larger surface unit cells, limiting the applicability of theoretical studies of smaller surface unit cells to heterogeneous catalysts with small defect densities.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 9.353
DOI: 10.1021/ACS.JPCLETT.1C03395
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“Acoustic cavities in 2D heterostructures”. Zalalutdinov MK, Robinson JT, Fonseca JJ, LaGasse SW, Pandey T, Lindsay LR, Reinecke TL, Photiadis DM, Culbertson JC, Cress CD, Houston BH, Nature Communications 12, 3267 (2021). http://doi.org/10.1038/S41467-021-23359-7
Abstract: Two-dimensional (2D) materials offer unique opportunities in engineering the ultrafast spatiotemporal response of composite nanomechanical structures. In this work, we report on high frequency, high quality factor (Q) 2D acoustic cavities operating in the 50-600GHz frequency (f) range with f x Q up to 1 x 10(14). Monolayer steps and material interfaces expand cavity functionality, as demonstrated by building adjacent cavities that are isolated or strongly-coupled, as well as a frequency comb generator in MoS2/h-BN systems. Energy dissipation measurements in 2D cavities are compared with attenuation derived from phonon-phonon scattering rates calculated using a fully microscopic ab initio approach. Phonon lifetime calculations extended to low frequencies (<1THz) and combined with sound propagation analysis in ultrathin plates provide a framework for designing acoustic cavities that approach their fundamental performance limit. These results provide a pathway for developing platforms employing phonon-based signal processing and for exploring the quantum nature of phonons. Here, authors report on acoustic cavities in 2D materials operating in the 50-600GHz range and show that quality factors approach the limit set by lattice anharmonicity. Functionality expanded by heterogeneities (steps and interfaces) is demonstrated through coupled cavities and frequency comb generation.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 12.124
DOI: 10.1038/S41467-021-23359-7
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“Acoustic simulation of noise barriers and prediction of annoyance for local residents”. Grangeiro de Barros A, Devroede R, Vanlanduit S, Vuye C, Kampen JK, , 1 (2021)
Abstract: Road traffic is the most widespread environmental noise source in Europe, proven to affect human health and well-being adversely. Noise barriers can be a very effective way to objectively reduce the noise levels to which the population is exposed, leading to positive effects on noise perception and quality of life. In this paper, surveys were used to assess subjective noise level indicators (annoyance and quality of life) from residents of the vicinity of a highway where obsolete noise barriers were to be replaced. %HA before the barrier replacement was measured from the surveys (26.8%) and estimated based on the acoustic simulation and two existing exposure/response relationships (14.6 and 18.8% before and 13.6 and 8.3% after). The difference in the measured %HA to those calculated from the ERRs shows that those models might not estimate %HA fairly for small samples or particular situations where high Lden is reported. Noise annoyance correlated differently with the quality of life indicators: a weak link was observed with health problems, while a strong correlation was found with the comfort level to perform activities outdoors. Objective noise measurements gave LA,eq,(15 min.) reductions of 4.1dB(A) due to the new barrier, while in acoustics models, calculated as Lday, expected this reduction to be 5.2 dB(A). After replacing the noise barriers, a second survey could still not be distributed due to the unknown effect of the COVID-19 measures that are still active
Keywords: P1 Proceeding; Engineering sciences. Technology; Engineering Management (ENM); Condensed Matter Theory (CMT); Energy and Materials in Infrastructure and Buildings (EMIB); Social Epidemiology & Health Policy (SEHPO)
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“Acoustically driven stark effect in transition metal dichalcogenide monolayers”. Scolfaro D, Finamor M, Trinchao LO, Rosa BLT, Chaves A, Santos P V, Iikawa F, Couto ODD Jr, Acs Nano 15, 15371 (2021). http://doi.org/10.1021/ACSNANO.1C06854
Abstract: The Stark effect is one of the most efficient mechanisms to manipulate many-body states in nanostructured systems. In mono- and few-layer transition metal dichalcogenides, it has been successfully induced by optical and electric field means. Here, we tune the optical emission energies and dissociate excitonic states in MoSe2 monolayers employing the 220 MHz in-plane piezoelectric field carried by surface acoustic waves. We transfer the monolayers to high dielectric constant piezoelectric substrates, where the neutral exciton binding energy is reduced, allowing us to efficiently quench (above 90%) and red-shift the excitonic optical emissions. A model for the acoustically induced Stark effect yields neutral exciton and trion in-plane polarizabilities of 530 and 630 x 10(-5) meV/(kV/cm)(2), respectively, which are considerably larger than those reported for monolayers encapsulated in hexagonal boron nitride. Large in-plane polarizabilities are an attractive ingredient to manipulate and modulate multiexciton interactions in two-dimensional semiconductor nanostructures for optoelectronic applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 13.942
DOI: 10.1021/ACSNANO.1C06854
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“Adsorption of habitat and industry-relevant molecules on the MoSi₂N₄, monolayer”. Bafekry A, Faraji M, Fadlallah MM, Ziabari AA, Khatibani AB, Feghhi SAH, Ghergherehchi M, Gogova D, Applied Surface Science 564, 150326 (2021). http://doi.org/10.1016/J.APSUSC.2021.150326
Abstract: The adsorption of various environmental gas molecules, including H-2, N-2, CO, CO2, O-2, NO, NO2, SO2 H2O, H2S, NH3 and CH4, on the surface of the recently synthesized two dimensional MoSi2N4 (MSN) monolayer has been investigated by means of spin-polarized first-principles calculations. The most stable adsorption configuration, adsorption energy, and charge transfer have been computed. Due to the weak interaction between molecules studied with the MSN monolayer surface, the adsorption energy is small and does not yield any significant distortion of the MSN lattice, i.e., the interaction between the molecules and MSN monolayer surface is physisorption. We find that all molecules are physisorbed on the MSM surface with small charge transfer, acting as either charge acceptors or donors. The MSN monolayer is a semiconductor with an indirect band gap of 1.79 eV. Our theoretical estimations reveal that upon adsorption of H-2, N-2, CO, CO2, NO, H2O, H2S, NH3 and CH4 molecules, the semiconducting character of MSN monolayer is preserved and the band gap value is decreased to similar to 1.5 eV. However, the electronic properties of the MSN monolayer can be significantly altered by adsorption of O-2, NO and SO2, and a spin polarization with magnetic moments of 2, 1, 2 mu(B), respectively, can be introduced. Furthermore, we demonstrate that the band gap and the magnetic moment of adsorbed MSN monolayer can be significantly modulated by the concentration of NO and SO2 molecules. As the concentration of NO2 molecule increases, the magnetic moment increase from 1 mu(B) to 2 and 3 mu(B). In the case of the SO2 molecule with increasing of concentration, the band gap decreases from 1.2 eV to 1.1 and 0.9 eV. Obviously, our theoretical studies indicate that MSN monolayer-based sensor has a high application potential for O-2, NO, NO2 and SO2 detection.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.387
DOI: 10.1016/J.APSUSC.2021.150326
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Legrand S (2021) Advanced chemical imaging of artworks. 315 p
Abstract: Last century the field of heritage sciences expanded beyond imagination. The inventions of X-ray radiography and infrared reflectography allowed experts to investigate paintings below the surface as well. More recent developments led to the advent of the field of hyperspectral imaging, to which the advanced chemical imaging methods, used in this thesis work, belong. These techniques not only allow to identify the components present in artworks, but also to visualize their distribution over these objects. The resulting distribution maps permit a broader public to interpret the scientific data and to relate these results with the artwork itself. During this thesis work a range of flat artworks were investigated in a non-destructive manner using mainly two macroscopic imaging techniques: macroscopic X-ray fluorescence scanning and macroscopic Fourier transformed mid-infrared scanning in reflectance mode. The resulting images were sometimes supplemented with microscopic techniques on a minute selection of samples to fully understand the layer build-up, composition and distribution of these materials over the stratigraphy. Illuminated manuscripts pushed the interpretation of the macroscopic imaging techniques: due to the impossibility of sampling, all answers had to be obtained non-destructively. Documenting masterpieces such as the Ghent Altarpiece by means of chemical imaging techniques, helped the restoration team, assisted by the international commission to make the daring decision of manually removing the non-original paint layers. Scanning stained-glass windows allowed experts to document the panels, create situation reports, identify later infills and guide the restoration process in a more efficient manner. By initially applying non-destructive imaging techniques, many of the research/conservation questions could already be answered. Based on the resulting distribution maps, only a very limited amount of sampling was required to obtain a representative set to answer the remaining questions. In most cases the combination of multiple methods was necessary to fully understand the situation. A similar trend could be seen in the research field: the collaboration between divergent disciples was often required in order to explain all observations. In order to completely break through, the scanning speed of these techniques has to increase even more in order to cover an acceptable surface in one workday. Parallel with the operational speed, the (basic) data treatment should also be streamlined more in order to allow a broader user group to access the results. Once these two improvements are carried out, these techniques become accessible to a larger public.
Keywords: Doctoral thesis; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Pedrazo Tardajos A (2021) Advanced graphene supports for 3D in situ transmission electron microscopy. 247 p
Abstract: Transmission electron microscopy (TEM) is an ideal tool to investigate nanomaterials. The information from TEM experiments allows us to link the structure and composition of nanomaterials to their intrinsic physical properties. However, despite the significant evolution of the TEM field during the last two decades, major progress is still possible through the development of optimal TEM techniques and supports. The results presented in this thesis focus on the optimization of sample supports and their application. Among the different options, graphene has previously been reported as useful sample support for electron microscopy due to its unparalleled properties, for example, it is the thinnest known support and provides a protective effect to the sample under investigation. Unfortunately, commercial graphene grids show poor quality, in terms of intactness and cleanness, inhibiting their wide application within the field. Therefore, this thesis focuses on the application of optimized graphene TEM grids, obtained by transferring high quality graphene using an advanced procedure. This improvement on the transfer has enabled the visualization of materials with low contrast and high sensitivity towards the electron beam, such as surface ligands capping gold nanoparticles or metal halide perovskites. Furthermore, the implemented protocol is not only of interest for conventional TEM grids but also a major benefit for in situ TEM studies, where the sample is investigated in real time under certain stimuli. Hence, the same graphene transfer technology can be also applied to advanced in situ MEMS holders dedicated for both heating and gas experiments, where the thickness and insulating nature of the silicon nitride (Si3N4) support may hamper some applications. By engineering periodic arrays of holes in their Si3N4 membrane by focused ion beam, onto which the graphene is transferred, it has been possible to get proof-of-concept 3D in situ investigations of heat-induced morphological and compositional transformations of complex nanosystems. As an example, it has enabled the investigation of the possible phase-transition of metal halide perovskites upon heating using 2D and 3D structural characterization. Moreover, it has allowed the study of in situ three-dimensional nanoparticle dynamics during gas phase catalysis as well as the first steps that would lead towards the design and creation of the first Graphene Gas Cell. Consequently, implementation of the advanced graphene transfer technology described in this thesis is envisaged to impact a broad range of future experiments.
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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“Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review”. Pietanza LD, Guaitella O, Aquilanti V, Armenise I, Bogaerts A, Capitelli M, Colonna G, Guerra V, Engeln R, Kustova E, Lombardi A, Palazzetti F, Silva T, European Physical Journal D 75, 237 (2021). http://doi.org/10.1140/epjd/s10053-021-00226-0
Abstract: Numerous applications have required the study of CO2 plasmas since the 1960s, from CO2 lasers to spacecraft heat shields. However, in recent years, intense research activities on the subject have restarted because of environmental problems associated with CO2 emissions. The present review provides a synthesis of the current state of knowledge on the physical chemistry of cold CO2 plasmas. In particular, the different modeling approaches implemented to address specific aspects of CO2 plasmas are presented. Throughout the paper, the importance of conducting joint experimental, theoretical and modeling studies to elucidate the complex couplings at play in CO2 plasmas is emphasized. Therefore, the experimental data that are likely to bring relevant constraints to the different modeling approaches are first reviewed. Second, the calculation of some key elementary processes obtained with semi-empirical, classical and quantum methods is presented. In order to describe the electron kinetics, the latest coherent sets of cross section satisfying the constraints of “electron swarm” analyses are introduced, and the need for self-consistent calculations for determining accurate electron energy distribution function (EEDF) is evidenced. The main findings of the latest zero-dimensional (0D) global models about the complex chemistry of CO2 and its dissociation products in different plasma discharges are then given, and full state-to-state (STS) models of only the vibrational-dissociation kinetics developed for studies of spacecraft shields are described. Finally, two important points for all applications using CO2 containing plasma are discussed: the role of surfaces in contact with the plasma, and the need for 2D/3D models to capture the main features of complex reactor geometries including effects induced by fluid dynamics on the plasma properties. In addition to bringing together the latest advances in the description of CO2 non-equilibrium plasmas, the results presented here also highlight the fundamental data that are still missing and the possible routes that still need to be investigated.
Keywords: A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 1.288
DOI: 10.1140/epjd/s10053-021-00226-0
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“Agricultural technical efficiency of smallholder farmers in Ethiopia : a stochastic frontier approach”. Chekol Zewdie M, Moretti M, Tenessa DB, Ayele ZA, Nyssen J, Tsegaye EA, Minale AS, Van Passel S, Land 10, 246 (2021). http://doi.org/10.3390/LAND10030246
Abstract: In the past decade, to improve crop production and productivity, Ethiopia has embarked on an ambitious irrigation farming expansion program and has introduced new large- and small-scale irrigation initiatives. However, in Ethiopia, poverty remains a challenge, and crop productivity per unit area of land is very low. Literature on the technical efficiency (TE) of large-scale and small-scale irrigation user farmers as compared to the non-user farmers in Ethiopia is also limited. Investigating smallholder farmers' TE level and its principal determinants is very important to increase crop production and productivity and to improve smallholder farmers' livelihood and food security. Using 1026 household-level cross-section data, this study adopts a technology flexible stochastic frontier approach to examine agricultural TE of large-scale irrigation users, small-scale irrigation users and non-user farmers in Ethiopia. The results indicate that, due to poor extension services and old-style agronomic practices, the mean TE of farmers is very low (44.33%), implying that there is a wider room for increasing crop production in the study areas through increasing the TE of smallholder farmers without additional investment in novel agricultural technologies. Results also show that large-scale irrigation user farmers (21.05%) are less technically efficient than small-scale irrigation user farmers (60.29%). However, improving irrigation infrastructure shifts the frontier up and has a positive impact on smallholder farmers' output.
Keywords: A1 Journal article; Engineering Management (ENM)
DOI: 10.3390/LAND10030246
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