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Author Heyne, M.H.; Chiappe, D.; Meersschaut, J.; Nuytten, T.; Conard, T.; Bender, H.; Huyghebaert, C.; Radu, I.P.; Caymax, M.; de Marneffe, J.F.; Neyts, E.C.; De Gendt, S.; doi  openurl
  Title Multilayer MoS2 growth by metal and metal oxide sulfurization Type A1 Journal article
  Year 2016 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C  
  Volume 4 Issue 4 Pages 1295-1304  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract We investigated the deposition of MoS2 multilayers on large area substrates. The pre-deposition of metal or metal oxide with subsequent sulfurization is a promising technique to achieve layered films. We distinguish a different reaction behavior in metal oxide and metallic films and investigate the effect of the temperature, the H2S/H-2 gas mixture composition, and the role of the underlying substrate on the material quality. The results of the experiments suggest a MoS2 growth mechanism consisting of two subsequent process steps. At first, the reaction of the sulfur precursor with the metal or metal oxide occurs, requiring higher temperatures in the case of metallic film compared to metal oxide. At this stage, the basal planes assemble towards the diffusion direction of the reaction educts and products. After the sulfurization reaction, the material recrystallizes and the basal planes rearrange parallel to the substrate to minimize the surface energy. Therefore, substrates with low roughness show basal plane assembly parallel to the substrate. These results indicate that the substrate character has a significant impact on the assembly of low dimensional MoS2 films.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000370723300020 Publication Date 2016-01-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7526; 2050-7534 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.256 Times cited Open Access  
  Notes Approved Most recent IF: 5.256  
  Call Number UA @ lucian @ c:irua:132327 Serial 4211  
Permanent link to this record
 

 
Author Neyts, E.C. pdf  doi
openurl 
  Title The role of ions in plasma catalytic carbon nanotube growth : a review Type A1 Journal article
  Year 2015 Publication Frontiers of Chemical Science and Engineering Abbreviated Journal Front Chem Sci Eng  
  Volume 9 Issue 9 Pages 154-162  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract While it is well-known that the plasma-enhanced catalytic chemical vapor deposition (PECVD) of carbon nanotubes (CNTs) offers a number of advantages over thermal CVD, the influence of the various individual contributing factors is not well understood. Especially the role of ions is unclear, since ions in plasmas are generally associated with sputtering rather than with growing a material. Even so, various studies have demonstrated the beneficial effects of ion bombardment during the growth of CNTs. This review looks at the role of the ions in plasma-enhanced CNT growth as deduced from both experimental and simulation studies. Specific attention is paid to the beneficial effects of ion bombardment. Based on the available literature, it can be concluded that ions can be either beneficial or detrimental for carbon nanotube growth, depending on the exact conditions and the control over the growth process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000360319600003 Publication Date 2015-06-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2095-0179 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.712 Times cited 8 Open Access  
  Notes Approved Most recent IF: 1.712; 2015 IF: NA  
  Call Number UA @ lucian @ c:irua:127815 Serial 4239  
Permanent link to this record
 

 
Author Ali, S.; Myasnichenko, V.S.; Neyts, E.C. pdf  url
doi  openurl
  Title Size-dependent strain and surface energies of gold nanoclusters Type A1 Journal article
  Year 2016 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 18 Issue 18 Pages 792-800  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Gold nanocluster properties exhibit unique size-dependence. In this contribution, we employ reactive molecular dynamics simulations to calculate the size- and temperature-dependent surface energies, strain energies and atomic displacements for icosahedral, cuboctahedral, truncated octahedral and decahedral Au-nanoclusters. The calculations demonstrate that the surface energy decreases with increasing cluster size at 0 K but increases with size at higher temperatures. The calculated melting curves as a function of cluster size demonstrate the Gibbs-Thomson effect. Atomic displacements and strain are found to strongly depend on the cluster size and both are found to increase with increasing cluster size. These results are of importance for understanding the size-and temperature-dependent surface processes on gold nanoclusters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000369480600017 Publication Date 2015-11-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 37 Open Access  
  Notes Approved Most recent IF: 4.123  
  Call Number UA @ lucian @ c:irua:131626 Serial 4243  
Permanent link to this record
 

 
Author Zhang, Y.-R.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Influence of the Material Dielectric Constant on Plasma Generation inside Catalyst Pores Type A1 Journal article
  Year 2016 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 120 Issue 120 Pages 25923-25934  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma catalysis is gaining increasing interest for various environmental applications, but the crucial question is whether plasma can be created inside catalyst pores and under which conditions. In practice, various catalytic support materials are used, with various dielectric constants. We investigate here the influence of the dielectric constant on the plasma properties inside catalyst pores and in the sheath in front of the pores, for various pore sizes. The calculations are performed by a two-dimensional fluid model for an atmospheric pressure dielectric barrier discharge in helium. The electron impact ionization rate, electron temperature, electron and ion density, as well as the potential distribution and surface charge density, are analyzed for a better understanding of the discharge behavior inside catalyst pores. The results indicate that, in a 100 μm pore, the electron impact ionization in the pore, which is characteristic for the plasma generation inside the pore, is greatly enhanced for dielectric constants below 300. Smaller pore sizes only yield enhanced ionization for smaller dielectric constants, i.e., up to εr = 200, 150, and 50 for pore sizes of 50, 30, and 10 μm. Thus, the most common catalyst supports, i.e., Al2O3 and SiO2, which have dielectric constants around εr = 8−11 and 4.2, respectively, should allow more easily that microdischarges can be formed inside catalyst pores, even for smaller pore sizes. On the other hand, ferroelectric materials with dielectric constants above 300 never seem to yield plasma enhancement inside catalyst pores, not even for 100 μm pore sizes. Furthermore, it is clear that the dielectric constant of the material has a large effect on the extent of plasma enhancement inside the catalyst pores, especially in the range between εr = 4 and εr = 200. The obtained results are explained in detail based on the surface charge density at the pore walls,

and the potential distribution and electron temperature inside and above the pores. The results obtained with this model are

important for plasma catalysis, as the production plasma species in catalyst pores might affect the catalyst properties, and thus

improve the applications of plasma catalysis.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000388429100029 Publication Date 2016-11-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 34 Open Access  
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO) (Grant G.0217.14N), the National Natural Science Foundation of China (Grant 11405019), and the China Postdoctoral Science Foundation (Grant 2015T80244). This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI), and the University of Antwerp. Approved Most recent IF: 4.536  
  Call Number PLASMANT @ plasmant @ c:irua:138602 Serial 4319  
Permanent link to this record
 

 
Author Shirazi, M.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title DFT study of Ni-catalyzed plasma dry reforming of methane Type A1 Journal article
  Year 2017 Publication Applied catalysis : B : environmental Abbreviated Journal Appl Catal B-Environ  
  Volume 205 Issue 205 Pages 605-614  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract tWe investigated the plasma-assisted catalytic reactions for the production of value-added chemicalsfrom Ni-catalyzed plasma dry reforming of methane by means of density functional theory (DFT). Weinspected many activation barriers, from the early stage of adsorption of the major chemical fragmentsderived fromCH4andCO2molecules up to the formation of value-added chemicals at the surface, focusingon the formation of methanol, as well as the hydrogenation of C1and C2hydrocarbon fragments. Theactivation barrier calculations show that the presence of surface-bound H atoms and in some cases alsoremaining chemical fragments at the surface facilitates the formation of products. This implies that thehydrogenation of a chemical fragment on the hydrogenated crystalline surface is energetically favouredcompared to the simple hydrogenation of the chemical fragment at the bare Ni(111) surface. Indeed, thepresence of hydrogen modifies the electronic structure of the surface and the course of the reactions.We therefore conclude that surface-bound H atoms, and to some extent also the remaining chemicalfragments at the crystalline surface, induce the following effects: they facilitate associative desorption ofmethanol and ethane by increasing the rate of H-transfer to the adsorbed fragments while they impedehydrogenation of ethylene to ethane, thus promoting again the desorption of ethylene. Overall, they thusfacilitate the catalytic conversion of the formed fragments from CH4and CO2, into value-added chemicals.Finally, we believe that the retention of methane fragments, especially CH3, in the presence of surface-boundHatoms (as observed here for Ni) can be regarded as an identifier for the proper choice of a catalystfor the production of value-added chemicals.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000393931000063 Publication Date 2017-01-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0926-3373 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.446 Times cited 26 Open Access OpenAccess  
  Notes Financial support from the Reactive Atmospheric Plasmaprocessing –eDucation network (RAPID), through the EU 7thFramework Programme (grant agreement no. 606889) is grate-fully acknowledged. The calculations were performed using theTuring HPC infrastructure at the CalcUA core facility of the Univer-siteit Antwerpen, a division of the Flemish Supercomputer CenterVSC, funded by the Hercules Foundation, the Flemish Approved Most recent IF: 9.446  
  Call Number PLASMANT @ plasmant @ c:irua:139514 Serial 4343  
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Author Yusupov, M.; Van der Paal, J.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Synergistic effect of electric field and lipid oxidation on the permeability of cell membranes Type A1 Journal article
  Year 2017 Publication Biochimica et biophysica acta : G : general subjects Abbreviated Journal Bba-Gen Subjects  
  Volume 1861 Issue 1861 Pages 839-847  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Background: Strong electric fields are knownto affect cell membrane permeability,which can be applied for therapeutic purposes, e.g., in cancer therapy. A synergistic enhancement of this effect may be accomplished by the presence of reactive oxygen species (ROS), as generated in cold atmospheric plasmas. Little is known about the synergy between lipid oxidation by ROS and the electric field, nor on howthis affects the cell membrane permeability.

Method: We here conduct molecular dynamics simulations to elucidate the dynamics of the permeation process under the influence of combined lipid oxidation and electroporation. A phospholipid bilayer (PLB), consisting of di-oleoyl-phosphatidylcholine molecules covered with water layers, is used as a model system for the plasma membrane.

Results and conclusions:Weshow howoxidation of the lipids in the PLB leads to an increase of the permeability of the bilayer to ROS, although the permeation free energy barriers still remain relatively high. More importantly, oxidation of the lipids results in a drop of the electric field threshold needed for pore formation (i.e., electroporation) in the PLB. The created pores in the membrane facilitate the penetration of reactive plasma species deep into the cell interior, eventually causing oxidative damage.

General significance: This study is of particular interest for plasma medicine, as plasma generates both ROS and electric fields, but it is also of more general interest for applications where strong electric fields and ROS both come into play.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000397366200012 Publication Date 2017-01-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-4165 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.702 Times cited Open Access OpenAccess  
  Notes This work is financially supported by the Fund for Scientific Research Flanders (FWO; grant numbers: 1200216N and 11U5416N). The work was carried out using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flem Approved Most recent IF: 4.702  
  Call Number PLASMANT @ plasmant @ c:irua:140095 Serial 4413  
Permanent link to this record
 

 
Author Verlackt, C.C.W.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Atomic scale behavior of oxygen-based radicals in water Type A1 Journal article
  Year 2017 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys  
  Volume 50 Issue 50 Pages 11LT01  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Cold atmospheric pressure plasmas in and in contact with liquids represent a growing field of research for various applications. Understanding the interactions between the plasma generated species and the liquid is crucial. In this work we perform molecular dynamics (MD) simulations based on a quantum mechanical method, i.e. density-functional based tight-binding (DFTB), to examine the interactions of OH radicals and O atoms in bulk water. Our calculations reveal that the transport of OH radicals through water is not only governed by diffusion, but also by an equilibrium reaction of H-abstraction with water molecules. Furthermore, when two OH radicals encounter each other, they either form a stable cluster, or react, resulting in the formation of a new water molecule and an O atom. In addition,

the O atoms form either oxywater (when in singlet configuration) or they remain stable in solution (when in triplet configuration), stressing the important role that O atoms can play in aqueous solution, and in contact with biomolecules. Our observations are in line with both experimental and ab initio results from the literature.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000415252400001 Publication Date 2017-02-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.588 Times cited 11 Open Access OpenAccess  
  Notes The authors thank Peter Bruggeman (University of Minnesota, USA) and Jan Benedikt (Ruhr-Universität Bochum, Germany) for the interesting discussions regarding the existence of O in aqueous solutions. Furthermore, they acknowledge financial support from the Fund for Scientific Research (FWO) Flanders (project number G012413N). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. Approved Most recent IF: 2.588  
  Call Number PLASMANT @ plasmant @ c:irua:140845 Serial 4420  
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Author Neyts, E.C.; Brault, P. pdf  url
doi  openurl
  Title Molecular Dynamics Simulations for Plasma-Surface Interactions: Molecular Dynamics Simulations… Type A1 Journal article
  Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym  
  Volume 14 Issue 14 Pages 1600145  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma-surface interactions are in general highly complex due to the interplay of many concurrent processes. Molecular dynamics simulations provide insight in some of these processes, subject to the accessible time and length scales, and the availability of suitable force fields. In this introductory tutorial-style review, we aim to describe the current capabilities and limitations of molecular dynamics simulations in this field, restricting ourselves to low-temperature nonthermal plasmas. Attention is paid to the simulation of the various fundamental processes occurring, including sputtering, etching, implantation, and deposition, as well as to what extent the basic plasma components can be accounted for, including ground state and excited species, electric fields, ions, photons, and electrons. A number of examples is provided, giving an bird’s eye overview of the current state of the field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000393184600009 Publication Date 2016-09-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.846 Times cited 13 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 2.846  
  Call Number PLASMANT @ plasmant @ c:irua:141758 Serial 4488  
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Author Khalilov, U.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title Atomic-scale mechanisms of plasma-assisted elimination of nascent base-grown carbon nanotubes Type A1 Journal article
  Year 2017 Publication Carbon Abbreviated Journal Carbon  
  Volume 118 Issue 118 Pages 452-457  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Selective etching allows for obtaining carbon nanotubes with a specific chirality. While plasma-assisted etching has already been used to separate metallic tubes from their semiconducting counterparts, little is known about the nanoscale mechanisms of the etching process. We combine (reactive) molecular dynamics (MD) and force-bias Monte Carlo (tfMC) simulations to study H-etching of CNTs. In particular, during the hydrogenation and subsequent etching of both the carbon cap and the tube, they sequentially transform to different carbon nanostructures, including carbon nanosheet, nanowall, and polyyne chains, before they are completely removed from the surface of a substrate-bound Ni-nanocluster.We also found that onset of the etching process is different in the cases of the cap and the tube, although the overall etching scenario is similar in both cases. The entire hydrogenation/etching process for both cases is analysed in detail, comparing with available theoretical and experimental evidences.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000401120800053 Publication Date 2017-03-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.337 Times cited 2 Open Access OpenAccess  
  Notes U. K. gratefully acknowledges financial support from the Research Foundation – Flanders (FWO), Belgium (Grant No. 12M1315N). The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. The authors also thank Prof. A. C. T. van Duin for sharing the ReaxFF code. Approved Most recent IF: 6.337  
  Call Number PLASMANT @ plasmant @ c:irua:141915 Serial 4531  
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Author Khalilov, U.; Bogaerts, A.; Hussain, S.; Kovacevic, E.; Brault, P.; Boulmer-Leborgne, C.; Neyts, E.C. pdf  url
doi  openurl
  Title Nanoscale mechanisms of CNT growth and etching in plasma environment Type A1 Journal article
  Year 2017 Publication Journal of physics: D: applied physics Abbreviated Journal J Phys D Appl Phys  
  Volume 50 Issue 50 Pages 184001  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma-enhanced chemical deposition (PECVD) of carbon nanotubes has already been shown to allow chirality control to some extent. In PECVD, however, etching may occur simultaneously with the growth, and the occurrence of intermediate processes further significantly complicates the growth process.

We here employ a computational approach with experimental support to study the plasma-based formation of Ni nanoclusters, Ni-catalyzed CNT growth and subsequent etching processes, in order to understand the underpinning nanoscale mechanisms. We find that hydrogen is the dominant factor in both the re-structuring of a Ni film and the subsequent appearance of Ni nanoclusters, as well as in the CNT nucleation and etching processes. The obtained results are compared with available theoretical and experimental studies and provide a deeper understanding of the occurring nanoscale mechanisms in plasma-assisted CNT nucleation and growth.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000398300900001 Publication Date 2017-04-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.588 Times cited 6 Open Access OpenAccess  
  Notes UK gratefully acknowledges financial support from the Research Foundation – Flanders (FWO), Belgium (Grant No. 12M1315N). The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the Universiteit Antwerpen. The authors also thank Prof A C T van Duin for sharing the ReaxFF code. Approved Most recent IF: 2.588  
  Call Number PLASMANT @ plasmant @ c:irua:141918 Serial 4533  
Permanent link to this record
 

 
Author Khalilov, U.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title Toward the Understanding of Selective Si Nano-Oxidation by Atomic Scale Simulations Type A1 Journal article
  Year 2017 Publication Accounts of chemical research Abbreviated Journal Accounts Chem Res  
  Volume 50 Issue 50 Pages 796-804  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The continuous miniaturization of nanodevices, such as transistors, solar cells, and optical fibers, requires the controlled synthesis of (ultra)thin gate oxides (<10 nm), including Si gate-oxide (SiO2) with high quality at the atomic scale. Traditional thermal growth of SiO2 on planar Si surfaces, however, does not allow one to obtain such ultrathin oxide due to either the high oxygen diffusivity at high temperature or the very low sticking ability of incident oxygen at low temperature. Two recent techniques, both operative at low (room) temperature, have been put forward to overcome these obstacles: (i) hyperthermal oxidation of planar Si surfaces and (ii) thermal or plasma-assisted oxidation of nonplanar Si surfaces, including Si nanowires (SiNWs). These nanooxidation processes are, however, often difficult to study experimentally, due to the key intermediate processes taking place on the nanosecond time scale.

In this Account, these Si nano-oxidation techniques are discussed from a computational point of view and compared to both hyperthermal and thermal oxidation experiments, as well as to well-known models of thermal oxidation, including the Deal−Grove, Cabrera−Mott, and Kao models and several alternative mechanisms. In our studies, we use reactive molecular dynamics (MD) and hybrid MD/Monte Carlo simulation techniques, applying the Reax force field. The incident energy of oxygen species is chosen in the range of 1−5 eV in hyperthermal oxidation of planar Si surfaces in order to prevent energy-induced damage. It turns out that hyperthermal growth allows for two growth modes, where the ultrathin oxide thickness depends on either (1) only the kinetic energy of the incident oxygen species at a growth temperature below Ttrans = 600 K, or (2) both the incident energy and the growth temperature at a growth temperature above Ttrans. These modes are specific to such ultrathin oxides, and are not observed in traditional thermal oxidation, nor theoretically considered by already existing models. In the case of thermal or plasma-assisted oxidation of small Si nanowires, on the other hand, the thickness of the ultrathin oxide is a function of the growth temperature and the nanowire diameter. Below Ttrans, which varies with the nanowire diameter, partially oxidized SiNW are formed, whereas complete oxidation to a SiO2 nanowire occurs only above Ttrans. In both nano-oxidation processes at lower temperature (T < Ttrans), final sandwich c-Si|SiOx|a-SiO2 structures are obtained due to a competition between overcoming the energy barrier to penetrate into Si subsurface layers and the compressive stress (∼2−3 GPa) at the Si crystal/oxide interface. The overall atomic-simulation results strongly indicate that the thickness of the intermediate SiOx (x < 2) region is very limited (∼0.5 nm) and constant irrespective of oxidation parameters. Thus, control over the ultrathin SiO2 thickness with good quality is indeed possible by accurately tuning the oxidant energy, oxidation temperature and surface curvature.

In general, we discuss and put in perspective these two oxidation mechanisms for obtaining controllable ultrathin gate-oxide films, offering a new route toward the fabrication of nanodevices via selective nano-oxidation.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000399859800016 Publication Date 2017-04-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-4842 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 20.268 Times cited 5 Open Access OpenAccess  
  Notes Fonds Wetenschappelijk Onderzoek, 12M1315N ; Approved Most recent IF: 20.268  
  Call Number PLASMANT @ plasmant @ c:irua:142638 Serial 4561  
Permanent link to this record
 

 
Author Bruggeman, P.J.; Kushner, M.J.; Locke, B.R.; Gardeniers, J.G.E.; Graham, W.G.; Graves, D.B.; Hofman-Caris, R.C.H.M.; Maric, D.; Reid, J.P.; Ceriani, E.; Fernandez Rivas, D.; Foster, J.E.; Garrick, S.C.; Gorbanev, Y.; Hamaguchi, S.; Iza, F.; Jablonowski, H.; Klimova, E.; Kolb, J.; Krcma, F.; Lukes, P.; Machala, Z.; Marinov, I.; Mariotti, D.; Mededovic Thagard, S.; Minakata, D.; Neyts, E.C.; Pawlat, J.; Petrovic, Z.L.; Pflieger, R.; Reuter, S.; Schram, D.C.; Schröter, S.; Shiraiwa, M.; Tarabová, B.; Tsai, P.A.; Verlet, J.R.R.; von Woedtke, T.; Wilson, K.R.; Yasui, K.; Zvereva, G. url  doi
openurl 
  Title Plasma–liquid interactions: a review and roadmap Type A1 Journal article
  Year 2016 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T  
  Volume 25 Issue 5 Pages 053002  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on nonequilibrium plasmas.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000384715400001 Publication Date 2016-09-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.302 Times cited 460 Open Access  
  Notes This manuscript originated from discussions at the Lorentz Center Workshop ‘Gas/Plasma–Liquid Interface: Transport, Chemistry and Fundamental Data’ that took place at the Lorentz Center, Leiden University in the Netherlands from August 4, through August 8, 2014, and follow-up discussions since the workshop. All authors acknowledge the support of the Lorentz Center, the COST action TD1208 (Electrical Discharges with Liquids for Future Applications) and the Royal Dutch Academy of Sciences for their financial support. PJB, MJK, DBG and JEF acknowledge the support of the ‘Center on Control of Plasma Kinetics’ of the United States Department of Energy Office of Fusion Energy Science (DE-SC0001319). In addition, PJB and BRL acknowledge the support of the National Science Foundation (PHY 1500135 and CBET 1236225, respectively). In addition the enormous help of Mrs. Victoria Piorek (University of Minnesota) in the formatting of the final document including the references is gratefully acknowledged. Approved Most recent IF: 3.302  
  Call Number PLASMANT @ plasmant @ c:irua:144654 Serial 4628  
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Author Shirazi, M.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title A DFT study of H-dissolution into the bulk of a crystalline Ni(111) surface: a chemical identifier for the reaction kinetics Type A1 Journal article
  Year 2017 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 19 Issue 19 Pages 19150-19158  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this study, we investigated the diffusion of H-atoms to the subsurface and their further diffusion into the bulk of a Ni(111) crystal by means of density functional theory calculations in the context of thermal and plasma-assisted catalysis. The H-atoms at the surface can originate from the dissociative adsorption of H2 or CH4 molecules, determining the surface H-coverage. When a threshold H-coverage is passed, corresponding to 1.00 ML for the crystalline Ni(111) surface, the surface-bound H-atoms start to diffuse to the subsurface. A similar threshold coverage is observed for the interstitial H-coverage. Once the interstitial sites are filled up with a coverage above 1.00 ML of H, dissolution of interstitial H-atoms to the layer below the interstitial sites will be initiated. Hence, by applying a high pressure or inducing a reactive plasma and high temperature, increasing the H-flux to the surface, a large amount of hydrogen can diffuse in a crystalline metal like Ni and can be absorbed. The formation of metal hydride may modify the entire reaction kinetics of the system. Equivalently, the H-atoms in the bulk can easily go back to the surface and release a large amount of heat. In a plasma process, H-atoms are formed in the plasma, and therefore the energy barrier for dissociative adsorption is dismissed, thus allowing achievement of the threshold coverage without applying a high pressure as in a thermal process. As a result, depending on the crystal plane and type of metal, a large number of H-atoms can be dissolved (absorbed) in the metal catalyst, explaining the high efficiency of plasma-assisted catalytic reactions. Here, the mechanism of H-dissolution is established as a chemical identifier for the investigation of the reaction kinetics of a chemical process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000406334300034 Publication Date 2017-06-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 10 Open Access OpenAccess  
  Notes Financial support from the Reactive Atmospheric Plasma processIng – eDucation (RAPID) network, through the EU 7th Framework Programme (grant agreement no. 606889), is gratefully acknowledged. The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government department (EWI) and the Universiteit Antwerpen. Approved Most recent IF: 4.123  
  Call Number PLASMANT @ plasmant @ c:irua:144794 Serial 4633  
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Author Neyts, E.C.; Bal, K.M. pdf  doi
openurl 
  Title Effect of electric fields on plasma catalytic hydrocarbon oxidation from atomistic simulations Type A1 Journal article
  Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym  
  Volume 14 Issue 6 Pages e1600158  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The catalytic oxidative dehydrogenation of hydrocarbons is an industrially important process, in which selectivity is a key issue. We here investigate the conversion of methanol to formaldehyde on a vanadia surface employing long timescale simulations, reaching a time scale of seconds. In particular, we compare the thermal process to the case where an additional external electric field is applied, as would be the case in a direct plasma-catalysis setup. We find that the electric field influences the retention time of the molecules at the catalyst surface. These simulations provide an atomic scale insight in the thermal catalytic oxidative dehydrogenation process, and in how an external electric field may affect this process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos 000403699900013 Publication Date 2016-11-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.846 Times cited 2 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 2.846  
  Call Number UA @ lucian @ c:irua:144210 Serial 4647  
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Author Aussems, D.U.B.; Bal, K. M.; Morgan, T.W.; van de Sanden, M.C.M.; Neyts, E.C. url  doi
openurl 
  Title Atomistic simulations of graphite etching at realistic time scales Type A1 Journal article
  Year 2017 Publication Chemical science Abbreviated Journal Chem Sci  
  Volume 8 Issue 10 Pages 7160-7168  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Hydrogen–graphite interactions are relevant to a wide variety of applications, ranging from astrophysics to fusion devices and nano-electronics. In order to shed light on these interactions, atomistic simulation using Molecular Dynamics (MD) has been shown to be an invaluable tool. It suffers, however, from severe timescale

limitations. In this work we apply the recently developed Collective Variable-Driven Hyperdynamics (CVHD) method to hydrogen etching of graphite for varying inter-impact times up to a realistic value of 1 ms, which corresponds to a flux of 1020 m2 s1. The results show that the erosion yield, hydrogen surface coverage and species distribution are significantly affected by the time between impacts. This can be explained by the higher probability of C–C bond breaking due to the prolonged exposure to thermal stress and the subsequent transition from ion- to thermal-induced etching. This latter regime of thermal-induced etching – chemical erosion – is here accessed for the first time using atomistic simulations. In conclusion, this study demonstrates that accounting for long time-scales significantly affects ion bombardment simulations and should not be neglected in a wide range of conditions, in contrast to what is typically assumed.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000411730500055 Publication Date 2017-08-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-6520 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.668 Times cited 3 Open Access OpenAccess  
  Notes DIFFER is part of the Netherlands Organisation for Scientic Research (NWO). K. M. B. is funded as a PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientic Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government – department EWI. Approved Most recent IF: 8.668  
  Call Number PLASMANT @ plasmant @c:irua:145519 Serial 4707  
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Author Tinck, S.; Tillocher, T.; Georgieva, V.; Dussart, R.; Neyts, E.; Bogaerts, A. pdf  url
doi  openurl
  Title Concurrent effects of wafer temperature and oxygen fraction on cryogenic silicon etching with SF6/O2plasmas Type A1 Journal article
  Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym  
  Volume 14 Issue 9 Pages 1700018  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Cryogenic plasma etching is a promising technique for high-control wafer development with limited plasma induced damage. Cryogenic wafer temperatures effectively reduce surface damage during etching, but the fundamental mechanism is not well understood. In this study, the influences of wafer temperature, gas mixture and substrate bias on the (cryogenic) etch rates of Si with SF6/O2 inductively coupled plasmas are experimentally and computationally investigated. The etch rates are measured in situ with double-point reflectometry and a hybrid computational Monte Carlo – fluid model is applied to calculate plasma properties. This work allows the reader to obtain a better insight in the effects of wafer temperature on the etch rate and to find operating conditions for successful anisotropic (cryo)etching.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000410773200012 Publication Date 2017-04-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.846 Times cited Open Access Not_Open_Access  
  Notes Fonds Wetenschappelijk Onderzoek, 0880.212.840 ; Hercules Foundation; Flemish Government (Department EWI); Universiteit Antwerpen; Approved Most recent IF: 2.846  
  Call Number PLASMANT @ plasmant @c:irua:145637 Serial 4708  
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Author Bal, K.M.; Huygh, S.; Bogaerts, A.; Neyts, E.C. pdf  url
doi  openurl
  Title Effect of plasma-induced surface charging on catalytic processes: application to CO2activation Type A1 Journal article
  Year 2018 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T  
  Volume 27 Issue 2 Pages 024001  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Understanding the nature and effect of the multitude of plasma–surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M=Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000424520100001 Publication Date 2018-02-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.302 Times cited 19 Open Access OpenAccess  
  Notes KMB is funded as PhD fellow (aspirant) of the FWO-Flanders (Research Foundation—Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government— department EWI. Approved Most recent IF: 3.302  
  Call Number PLASMANT @ plasmant @c:irua:149285 Serial 4813  
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Author Razzokov, J.; Yusupov, M.; Vanuytsel, S.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Phosphatidylserine flip-flop induced by oxidation of the plasma membrane: a better insight by atomic scale modeling Type A1 Journal article
  Year 2017 Publication Plasma processes and polymers Abbreviated Journal Plasma Process Polym  
  Volume 14 Issue 10 Pages 1700013  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract We perform molecular dynamics simulations to study the flip-flop motion of phosphatidylserine (PS) across the plasma membrane upon increasing oxidation degree of the membrane. Our computational results show that an increase of the oxidation degree in the lipids leads to a decrease of the free energy barrier for translocation of PS through the membrane. In other words, oxidation of the lipids facilitates PS flip-flop motion across the membrane, because in native phospholipid bilayers this is only a “rare event” due to the high energy barriers for the translocation of PS. The present study provides an atomic-scale insight into the mechanisms of the PS flip-flop upon oxidation of lipids, as produced for example by cold atmospheric plasma, in living cells.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000413045800010 Publication Date 2017-04-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1612-8850 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.846 Times cited 9 Open Access Not_Open_Access  
  Notes Fonds Wetenschappelijk Onderzoek, 1200216N ; Approved Most recent IF: 2.846  
  Call Number PLASMANT @ plasmant @c:irua:149567 Serial 4910  
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Author Bal, K.M.; Neyts, E.C. pdf  url
doi  openurl
  Title Modelling molecular adsorption on charged or polarized surfaces: a critical flaw in common approaches Type A1 Journal article
  Year 2018 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys  
  Volume 20 Issue 13 Pages 8456-8459  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A number of recent computational material design studies based on density functional theory (DFT) calculations have put forward a new class of materials with electrically switchable chemical characteristics that can be exploited in the development of tunable gas storage and electrocatalytic applications. We find systematic flaws in almost every computational study of gas adsorption on polarized or charged surfaces, stemming from an improper and unreproducible treatment of periodicity, leading to very large errors of up to 3 eV in some cases. Two simple corrective procedures that lead to consistent results are proposed, constituting a crucial course correction to the research in the field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000428779700007 Publication Date 2018-03-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-9076 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.123 Times cited 8 Open Access OpenAccess  
  Notes K. M. B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Research Foundation – Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government – department EWI. Approved Most recent IF: 4.123  
  Call Number PLASMANT @ plasmant @c:irua:150357 Serial 4916  
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Author Heyne, M.H.; de Marneffe, J.-F.; Nuytten, T.; Meersschaut, J.; Conard, T.; Caymax, M.; Radu, I.; Delabie, A.; Neyts, E.C.; De Gendt, S. pdf  url
doi  openurl
  Title The conversion mechanism of amorphous silicon to stoichiometric WS2 Type A1 Journal article
  Year 2018 Publication Journal of materials chemistry C : materials for optical and electronic devices Abbreviated Journal J Mater Chem C  
  Volume 6 Issue 15 Pages 4122-4130  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The deposition of ultra-thin tungsten films and their related 2D chalcogen compounds on large area dielectric substrates by gas phase reactions is challenging. The lack of nucleation sites complicates the adsorption of W-related precursors and subsequent sulfurization usually requires high temperatures. We propose here a technique in which a thin solid amorphous silicon film is used as reductant for the gas phase precursor WF6 leading to the conversion to metallic W. The selectivity of the W conversion towards the underlying dielectric surfaces is demonstrated. The role of the Si surface preparation, the conversion temperature, and Si thickness on the formation process is investigated. Further, the in situ conversion of the metallic tungsten into thin stoichiometric WS2 is achieved by a cyclic approach based on WF6 and H2S pulses at the moderate temperature of 450 1C, which is much lower than usual oxide sulfurization processes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000430538000036 Publication Date 2018-03-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-7526 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 5.256 Times cited 4 Open Access OpenAccess  
  Notes This work was supported throughout a strategic fundamental research grant for M. H. by the agency Flanders innovation & entrepreneurship (VLAIO). Approved Most recent IF: 5.256  
  Call Number PLASMANT @ plasmant @c:irua:150968 Serial 4921  
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Author Neyts, E.C. pdf  doi
openurl 
  Title Atomistic simulations of plasma catalytic processes Type A1 Journal article
  Year 2018 Publication Frontiers of Chemical Science and Engineering Abbreviated Journal Front Chem Sci Eng  
  Volume 12 Issue 1 Pages 145-154  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract There is currently a growing interest in the realisation and optimization of hybrid plasma/catalyst systems for a multitude of applications, ranging from nanotechnology to environmental chemistry. In spite of this interest, there is, however, a lack in fundamental understanding of the underlying processes in such systems. While a lot of experimental research is already being carried out to gain this understanding, only recently the first simulations have appeared in the literature. In this contribution, an overview is presented on atomic scale simulations of plasma catalytic processes as carried out in our group. In particular, this contribution focusses on plasma-assisted catalyzed carbon nanostructure growth, and plasma catalysis for greenhouse gas conversion. Attention is paid to what can routinely be done, and where challenges persist.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000425156500017 Publication Date 2017-09-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2095-0179 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.712 Times cited 5 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 1.712  
  Call Number UA @ lucian @ c:irua:149233 Serial 4927  
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Author Nematollahi, P.; Neyts, E.C. doi  openurl
  Title A comparative DFT study on CO oxidation reaction over Si-doped BC2N nanosheet and nanotube Type A1 Journal article
  Year 2018 Publication Applied surface science Abbreviated Journal Appl Surf Sci  
  Volume 439 Issue 439 Pages 934-945  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this study, we performed density functional theory (DFT) calculations to investigate different reaction mechanisms of CO oxidation catalyzed by the Si atom embedded defective BC2N nanostructures as well as the analysis of the structural and electronic properties. The structures of all the complexes are optimized and characterized by frequency calculations at the M062X/6-31G* computational level. Also, The electronic structures and thermodynamic parameters of adsorbed CO and O-2 molecules over Si-doped BC2N nanostructures are examined in detail. Moreover, to investigate the curvature effect on the CO oxidation reaction, all the adsorption and CO oxidation reactions on a finite-sized armchair (6,6) Si-BC2NNT are also studied. Our results indicate that there can be two possible pathways for the CO oxidation with O-2 molecule: O-2(g) + CO(g) -> O-2(ads) + CO(ads) -> CO2(g) + O-(ads) and O-(ads) + CO(g) -> CO2(g). The first reaction proceeds via the Langmuir-Hinshelwood (LH) mechanism while the second goes through the Eley-Rideal (ER) mechanism. On the other hand, by increasing the tube diameter, the energy barrier increases due to the strong adsorption energy of the O-2 molecule which is related to its dissociation over the tube surface. Our calculations indicate that the two step energy barrier of the oxidation reaction over Si-BC2NNS is less than that over the Si-BC2NNT. Hence, Si-BC2NNS may serve as an efficient and highly activated substrate to CO oxidation rather than (4,4) Si-BC2NNT. (C) 2018 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000427457100112 Publication Date 2018-01-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.387 Times cited 8 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 3.387  
  Call Number UA @ lucian @ c:irua:150745 Serial 4960  
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Author Wang, Z.; Zhang, Y.; Neyts, E.C.; Cao, X.; Zhang, X.; Jang, B.W.-L.; Liu, C.-jun doi  openurl
  Title Catalyst preparation with plasmas : how does it work? Type A1 Journal article
  Year 2018 Publication ACS catalysis Abbreviated Journal Acs Catal  
  Volume 8 Issue 3 Pages 2093-2110  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Catalyst preparation with plasmas is increasingly attracting interest. A plasma is a partially ionized gas, consisting of electrons, ions, molecules, radicals, photons, and excited species, which are all active species for catalyst preparation and treatment. Under the influence of plasma, nucleation and crystal growth in catalyst preparation can be very different from those in the conventional thermal approach. Some thermodynamically unfavorable reactions can easily take place with plasmas. Compounds such as sulfides, nitrides, and phosphides that are produced under harsh conditions can be synthesized by plasma under mild conditions. Plasmas can produce catalysts with smaller particle sizes and controllable structure. Plasma is also a facile tool for reduction, oxidation, doping, etching, coating, alloy formation, surface treatment, and surface cleaning in a simple and direct way. A rapid and convenient plasma template removal has thus been established for zeolite synthesis. It can operate at room temperature and allows the catalyst preparation on temperature-sensitive supporting materials. Plasma is typically effective for the production of various catalysts on metallic substrates. In addition, plasma-prepared transition-metal catalysts show enhanced low-temperature activity with improved stability. This provides a useful model catalyst for further improvement of industrial catalysts. In this review, we aim to summarize the recent advances in catalyst preparation with plasmas. The present understanding of plasma-based catalyst preparation is discussed. The challenges and future development are addressed.  
  Address  
  Corporate Author Thesis  
  Publisher Amer chemical soc Place of Publication Washington Editor  
  Language Wos 000426804100055 Publication Date 2018-01-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2155-5435 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.614 Times cited 81 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 10.614  
  Call Number UA @ lucian @ c:irua:150880 Serial 4963  
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Author Aussems, D.U.B.; Bal, K.M.; Morgan, T.W.; van de Sanden, M.C.M.; Neyts, E.C. pdf  url
doi  openurl
  Title Mechanisms of elementary hydrogen ion-surface interactions during multilayer graphene etching at high surface temperature as a function of flux Type A1 Journal article
  Year 2018 Publication Carbon Abbreviated Journal Carbon  
  Volume 137 Issue Pages 527-532  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In order to optimize the plasma-synthesis and modification process of carbon nanomaterials for applications such as nanoelectronics and energy storage, a deeper understanding of fundamental hydrogengraphite/graphene interactions is required. Atomistic simulations by Molecular Dynamics have proven to be indispensable to illuminate these phenomena. However, severe time-scale limitations restrict them to very fast processes such as reflection, while slow thermal processes such as surface diffusion and molecular desorption are commonly inaccessible. In this work, we could however reach these thermal processes for the first time at time-scales and surface temperatures (1000 K) similar to high-flux plasma exposure experiments during the simulation of multilayer graphene etching by 5 eV H ions. This was achieved by applying the Collective Variable-Driven Hyperdynamics biasing technique, which extended the inter-impact time over a range of six orders of magnitude, down to a more realistic ion-flux of 1023m2s1. The results show that this not only causes a strong shift from predominant ion-to thermally induced interactions, but also significantly affects the hydrogen uptake and surface evolution. This study thus elucidates H ion-graphite/graphene interaction mechanisms and stresses the importance of including long time-scales in atomistic simulations at high surface temperatures to understand the dynamics of the ion-surface system.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000440661700056 Publication Date 2018-05-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.337 Times cited 4 Open Access Not_Open_Access: Available from 25.05.2020  
  Notes DIFFER is part of the Netherlands Organisation for Scientific Research (NWO). K.M.B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientific Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government e department EWI. Approved Most recent IF: 6.337  
  Call Number PLASMANT @ plasmant @c:irua:152172 Serial 4993  
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Author Zhang, Y.-R.; Neyts, E.C.; Bogaerts, A. pdf  url
doi  openurl
  Title Enhancement of plasma generation in catalyst pores with different shapes Type A1 Journal article
  Year 2018 Publication Plasma sources science and technology Abbreviated Journal Plasma Sources Sci T  
  Volume 27 Issue 5 Pages 055008  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000432351700002 Publication Date 2018-05-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1361-6595 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.302 Times cited 11 Open Access OpenAccess  
  Notes This work was supported by the Fund for Scientific Research Flanders (FWO) (Grant No. G.0217.14N) and the Fundamental Research Funds for the Central Universities (Grant No. DUT17LK52). Approved Most recent IF: 3.302  
  Call Number PLASMANT @ plasmant @c:irua:151546 Serial 4998  
Permanent link to this record
 

 
Author Nematollahi, P.; Esrafili, M.D.; Neyts, E.C. pdf  url
doi  openurl
  Title The role of healed N-vacancy defective BC2N sheet and nanotube by NO molecule in oxidation of NO and CO gas molecules Type A1 Journal article
  Year 2018 Publication Surface science : a journal devoted to the physics and chemistry of interfaces Abbreviated Journal Surf Sci  
  Volume 672-673 Issue 672-673 Pages 39-46  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this study, the healing of N-vacancy boron carbonitride nanosheet (NV-BC2NNS) and nanotube (NV-BC2NNT) by NO molecule is studied by means of density functional theory calculations. Two different N-vacancies are considered in each of these structures in which the vacancy site is surrounded by either three B-atoms (NB) or by two B- and one C-atom (NBC). By means of the healed BC2NNS and BC2NNT as a support, the removal of two toxic gas molecules (NO and CO) are applicable. It should be noted that the obtained energy barriers of both healing and oxidizing processes are significantly lower than those of graphene, carbon nanotubes or boron nitride nanostructures. Also, at the end of the oxidation process, the pure BC2NNS or BC2NNT is obtained without any additional defects. Therefore, by using this method, we can considerably purify the defective BC2NNS/BC2NNT. Moreover, according to the thermochemistry calculations we can further confirm that the healing process of the NV-BC2NNS and NV-BC2NNT by NO are feasible at room temperature. So, we can claim that this study could be very helpful in both purifying the defective BC2NNS/BC2NNT while in the same effort removing toxic NO and CO gases.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000432614700007 Publication Date 2018-03-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0039-6028 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.062 Times cited 1 Open Access OpenAccess  
  Notes Approved Most recent IF: 2.062  
  Call Number UA @ lucian @ c:irua:151478 Serial 5044  
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Author Heyne, M.H.; de Marneffe, J.-F.; Radu, I.; Neyts, E.C.; De Gendt, S. pdf  doi
openurl 
  Title Thermal recrystallization of short-range ordered WS2 films Type A1 Journal article
  Year 2018 Publication Journal of vacuum science and technology: A: vacuum surfaces and films Abbreviated Journal J Vac Sci Technol A  
  Volume 36 Issue 5 Pages 05g501  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The integration of van der Waals materials in nanoelectronic devices requires the deposition of few-layered MX2 films with excellent quality crystals covering a large area. In recent years, astonishing progress in the monolayer growth of WS2 and MoS2 was demonstrated, but multilayer growth resulted often in separated triangular or hexagonal islands. These polycrystalline films cannot fully employ the specific MX2 properties since they are not connected in-plane to the other domains. To coalesce separated islands, ultrahigh-temperature postdeposition anneals in H2S are applied, which are not compatible with bare silicon substrates. Starting from the deposition of stoichiometric short-ordered films, the present work studies different options for subsequent high-temperature annealing in an inert atmosphere to form crystalline films with large grains from stoichiometric films with small grains. The rapid thermal annealing, performed over a few seconds, is compared to excimer laser annealing in the nanosecond range, which are both able to crystallize the thin WS2. The WS2 recrystallization temperature can be lowered using metallic crystallization promoters (Co and Ni). The best result is obtained using a Co cap, due to the circumvention of Co and S binary phase formation below the eutectic temperature. The recrystallization above a critical temperature is accompanied by sulfur loss and 3D regrowth. These undesired effects can be suppressed by the application of a dielectric capping layer prior to annealing. A SiO2 cap can suppress the sulfur loss successfully during annealing and reveals improved material quality in comparison to noncapped films Published by the AVS.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000444033200002 Publication Date 2018-07-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0734-2101 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.374 Times cited 2 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 1.374  
  Call Number UA @ lucian @ c:irua:153671 Serial 5134  
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Author Khalilov, U.; Vets, C.; Neyts, E.C. pdf  doi
openurl 
  Title Catalyzed growth of encapsulated carbyne Type A1 Journal article
  Year 2019 Publication Carbon Abbreviated Journal Carbon  
  Volume 153 Issue Pages 1-5  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Carbyne is a novel material of current interest in nanotechnology. As is typically the case for nanomaterials, the growth process determines the resulting properties. While endohedral carbyne has been successfully synthesized, its catalyst and feedstock-dependent growth mechanism is still elusive. We here study the nucleation and growth mechanism of different carbon chains in a Ni-containing double walled carbon nanotube using classical molecular dynamics simulations and first-principles calculations. We find that the understanding the competitive role of the metal catalyst and the hydrocarbon is important to control the growth of 1-dimensional carbon chains, including Ni or H-terminated carbyne. Also, we find that the electronic property of the Ni-terminated carbyne can be tuned by steering the H concentration along the chain. These results suggest catalyst-containing carbon nanotubes as a possible synthesis route for carbyne formation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000485054200001 Publication Date 2019-07-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0008-6223 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.337 Times cited Open Access Not_Open_Access  
  Notes Fund of Scientific Research Flanders (FWO), Belgium, 12M1318N 1S22516N ; Flemish Supercomputer Centre VSC; Hercules Foundation; Flemish Government; University of Antwerp; The authors gratefully acknowledge the financial support from the Fund of Scientific Research Flanders (FWO), Belgium, Grant numbers 12M1318N and 1S22516N. The work was carried out in part using the Turing HPC infrastructure of the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. Approved Most recent IF: 6.337  
  Call Number PLASMANT @ plasmant @c:irua:160695 Serial 5187  
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Author Heyne, M.H.; Marinov, D.; Braithwaite, N.; Goodyear, A.; de Marneffe, J.-F.; Cooke, M.; Radu, I.; Neyts, E.C.; De Gendt, S. pdf  doi
openurl 
  Title A route towards the fabrication of 2D heterostructures using atomic layer etching combined with selective conversion Type A1 Journal article
  Year 2019 Publication 2D materials Abbreviated Journal 2D Mater  
  Volume 6 Issue 3 Pages 035030  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Heterostructures of low-dimensional semiconducting materials, such as transition metal dichalcogenides (MX2), are promising building blocks for future electronic and optoelectronic devices. The patterning of one MX2 material on top of another one is challenging due to their structural similarity. This prevents an intrinsic etch stop when conventional anisotropic dry etching processes are used. An alternative approach consist in a two-step process, where a sacrificial silicon layer is pre-patterned with a low damage plasma process, stopping on the underlying MoS2 film. The pre-patterned layer is used as sacrificial template for the formation of the top WS2 film. This study describes the optimization of a cyclic Ar/Cl-2 atomic layer etch process applied to etch silicon on top of MoS2, with minimal damage, followed by a selective conversion of the patterned Si into WS2. The impact of the Si atomic layer etch towards the MoS2 is evaluated: in the ion energy range used for this study, MoS2 removal occurs in the over-etch step over 1-2 layers, leading to the appearance of MoOx but without significant lattice distortions to the remaining layers. The combination of Si atomic layer etch, on top of MoS2, and subsequent Si-to-WS2 selective conversion, allows to create a WS2/MoS2 heterostructure, with clear Raman signals and horizontal lattice alignment. These results demonstrate a scalable, transfer free method to achieve horizontally individually patterned heterostacks and open the route towards wafer-level processing of 2D materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000468335500004 Publication Date 2019-04-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.937 Times cited Open Access Not_Open_Access  
  Notes Approved Most recent IF: 6.937  
  Call Number UA @ admin @ c:irua:160229 Serial 5266  
Permanent link to this record
 

 
Author Grubova, I.Y.; Surmeneva, M.A.; Huygh, S.; Surmenev, R.A.; Neyts, E.C. pdf  doi
openurl 
  Title Effects of silicon doping on strengthening adhesion at the interface of the hydroxyapatite-titanium biocomposite : a first-principles study Type A1 Journal article
  Year 2019 Publication Computational materials science Abbreviated Journal Comp Mater Sci  
  Volume 159 Issue 159 Pages 228-234  
  Keywords (down) A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this paper we employ first-principles calculations to investigate the effect of substitutional Si doping in the amorphous calcium-phosphate (a-HAP) structure on the work of adhesion, integral charge transfer, charge density difference and theoretical tensile strengths between an a-HAP coating and amorphous titanium dioxide (a-TiO2) substrate systemically. Our calculations demonstrate that substitution of a P atom by a Si atom in a-HAP (a-Si-HAP) with the creation of OH-vacancies as charge compensation results in a significant increase of the bonding strength of the coating to the substrate. The work of adhesion of the optimized Si-doped interfaces reaches a value of up to -2.52 J m(-2), which is significantly higher than for the stoichiometric a-HAP/a-TiO2. Charge density difference analysis indicates that the dominant interactions at the interface have significant covalent character, and in particular two Ti-O and three Ca-O bonds are formed for a-Si-HAP/a-TiO2 and one Ti-O and three Ca-O bonds for a-HAP/a-TiO2. From the stress-strain curve, the Young's modulus of a-Si-HAP/a-TiO2 is calculated to be about 25% higher than that of the a-HAP/a-TiO2, and the yielding stress is about 2 times greater than that of the undoped model. Our calculations therefore demonstrate that the presence of Si in the a-HAP structure strongly alters not only the bioactivity and resorption rates, but also the mechanical properties of the a-HAP/a-TiO2 interface. The results presented here provide an important theoretical insight into the nature of the chemical bonding at the a-HAP/a-TiO2 interface, and are particularly significant for the practical medical applications of HAP-based biomaterials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000457856900023 Publication Date 2018-12-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0927-0256 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.292 Times cited 1 Open Access Not_Open_Access  
  Notes Approved Most recent IF: 2.292  
  Call Number UA @ admin @ c:irua:157480 Serial 5272  
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