| |
Records |
Links |
|
Author |
Janssens, K.; van der Snickt, G.; Alfeld, M.; Noble, P.; van Loon, A.; Delaney, J.; Conover, D.; Zeibel, J.; Dik, J. |
|
| |
Title |
Rembrandt's 'Saul and David' (c. 1652) : use of multiple types of smalt evidenced by means of non-destructive imaging |
Type |
A1 Journal article |
| |
Year  |
2016 |
Publication |
Microchemical journal |
Abbreviated Journal |
Microchem J |
|
| |
Volume |
126 |
Issue |
|
Pages |
515-523 |
|
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
The painting Saul and David, considered to date from c. 1652 and previously attributed to Rembrandt van Rijn and/or his studio, is a complex work of art that has been recently subjected to intensive investigation and conservation treatment. The goal of the research was to give insight into the painting's physical construction and condition in preparation for conservation treatment. It was also anticipated that analysis would shed light on authenticity questions and Rembrandt's role in the creation of the painting. The painting depicts the Old Testament figures of King Saul and David. At left is Saul, seated, holding a spear and wiping a tear from his eye with a curtain. David kneels before him at the right playing his harp. In the past, the large sections with the life-size figures were cut apart and later reassembled. A third piece of canvas was added to replace a missing piece of canvas above the head of David. As part of the investigation into the authenticity of the curtain area, a number of paint micro samples were examined with LM and SEM-EDX. Given that the earth, smalt and lake pigments used in the painting could not be imaged with traditional imaging techniques, the entire painting was also examined with state of the art non-destructive imaging techniques. Special attention was devoted to the presence of cobalt-containing materials, specifically the blue glass pigment smalt considered characteristic for the late Rembrandt. A combination of quantitative electron microprobe analysis and macroscopic X-ray fluorescence scanning revealed that three types of cobalt-containing materials are present in the painting. The first type is a cobalt drier that was found in the overpaint used to cover up the canvas inset and the joins that were added in the 19th century. The other two Co-containing materials are part of the original paint used by Rembrandt and comprise two varieties of smalt, a K-rich glass pigment that derives its gray-blue color by doping with Co-ions. Smalt paint with a higher Ni content (NiO:CoO ratio of around 1:4) was used to depict the blue stripes in Saul's colorful turban, while smalt with a lower Ni content was employed (NiO:CoO ratio of around 1:5) for the broad expanses of Saul's garments. The presence of two types of smalt not only supports the recent re-attribution of the painting to Rembrandt, but also that the picture was painted in two phases. Saul's dark red garment is painted in a rough, “loose” manner and the now discolored smalt-rich layer was found to have been partially removed during a past restoration treatment/s. In contrast, the blue-green smalt in the turban is much better preserved and provides a colorful accent. While the use of different types of smalt in a Rembrandt painting has been previously identified using quantitative EDX analysis of paint cross-sections, to the best of our knowledge this is the first time such a distinction has been observed in a 17th-century painting using non-destructive imaging techniques. In addition to the XRF-based non-invasive elemental mapping, hyperspectral imaging in the visual to near-infrared (VNIR) region was also carried out. (C) 2016 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000373647500063 |
Publication Date |
2016-01-29 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0026-265x; 0026-265x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.034 |
Times cited |
18 |
Open Access |
|
|
| |
Notes |
; This research is part of the ReVisualising late Rembrandt: Developing and Applying New Imaging Techniques research project, supported by the Science4Arts research program of the Netherlands Organisation for Scientific Research (NWO, The Hague, NL, ReVisRembrandt project) and the National Science Foundation (NSF, Washington DC, USA, award 1041827). We would like to thank colleagues of the Mauritshuis (The Hague, NL) and the Dutch Cultural Heritage Agency (RCE) in Rijswijk, NL for their support and assistance during the scanning of the Saul and David painting. The GOA project “SOLARPAINT” (University of Antwerp) and the Fund Baillet Latour (Brussels, B) are acknowledged for financial support to GvdS and KJ. We also like to acknowledge the help of Eliza Longhini and Stijn Legrand during some of the XRF scanning stages. ; |
Approved |
Most recent IF: 3.034 |
|
| |
Call Number |
UA @ admin @ c:irua:133258 |
Serial |
5813 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hamidi-Asl, E.; Dardenne, F.; Pilehvar, S.; Blust, R.; De Wael, K. |
|
| |
Title |
Unique properties of core shell Ag@Au nanoparticles for the aptasensing of bacterial cells |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemosensors |
Abbreviated Journal |
|
|
| |
Volume |
4 |
Issue |
3 |
Pages |
16 |
|
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
In this article, it is shown that the efficiency of an electrochemical aptasensing device is influenced by the use of different nanoparticles (NPs) such as gold nanoparticles (Au), silver nanoparticles (Ag), hollow gold nanospheres (HGN), hollow silver nanospheres (HSN), silvergold core shell (Ag@Au), goldsilver core shell (Au@Ag), and silvergold alloy nanoparticles (Ag/Au). Among these nanomaterials, Ag@Au core shell NPs are advantageous for aptasensing applications because the core improves the physical properties and the shell provides chemical stability and biocompatibility for the immobilization of aptamers. Self-assembly of the NPs on a cysteamine film at the surface of a carbon paste electrode is followed by the immobilization of thiolated aptamers at these nanoframes. The nanostructured (Ag@Au) aptadevice for Escherichia coli as a target shows four times better performance in comparison to the response obtained at an aptamer modified planar gold electrode. A comparison with other (core shell) NPs is performed by cyclic voltammetry and differential pulse voltammetry. Also, the selectivity of the aptasensor is investigated using other kinds of bacteria. The synthesized NPs and the morphology of the modified electrode are characterized by UV-Vis absorption spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and electrochemical impedance spectroscopy. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000382480000006 |
Publication Date |
2016-08-29 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2227-9040 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
9 |
Open Access |
|
|
| |
Notes |
; Ezat Hamidi-Asl was financially supported by Belspo (University of Antwerp). The authors are thankful to Femke De Croock for her technical support and to Stanislav Trashin for his worthwhile comments on the manuscript. ; |
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ admin @ c:irua:135411 |
Serial |
5886 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ayalew, E.; Janssens, K.; De Wael, K. |
|
| |
Title |
Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
|
| |
Volume |
88 |
Issue |
3 |
Pages |
1564-1569 |
|
| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000369471100014 |
Publication Date |
2015-12-31 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.32 |
Times cited |
9 |
Open Access |
|
|
| |
Notes |
; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; |
Approved |
Most recent IF: 6.32 |
|
| |
Call Number |
UA @ admin @ c:irua:129963 |
Serial |
5888 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
van Walsem, J.; Verbruggen, S.W.; Modde, B.; Lenaerts, S.; Denys, S. |
|
| |
Title |
CFD investigation of a multi-tube photocatalytic reactor in non-steady-state conditions |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
|
| |
Volume |
304 |
Issue |
|
Pages |
808-816 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
A novel multi-tube photoreactor is presented with a high efficiency (over 90% conversion) toward the degradation of acetaldehyde in air under UV conditions with an incident intensity of 2.1 mW cm−2. A CFD model was developed to simulate the transient adsorption and photocatalytic degradation processes of acetaldehyde in this reactor design and to estimate the corresponding kinetic parameters through an optimization routine using the experimentally determined outlet concentration profiles. The CFD model takes into account the entire reactor geometry and all relevant flow parameters, in contrast to analytical methods that often oversimplify the physical and chemical process characteristics. Using CFD, we show that both adsorption and desorption rate constants increase by respectively one and two orders of magnitude when the UV light is switched on, which clearly affects the transient behavior. The agreement of the experimental and modelled concentration profiles is excellent as evidenced by a coefficient of determination of at least 0.965. To demonstrate the reliability and accuracy of all parameters obtained from the modelling approach, an ultimate validation test was performed using other conditions than the ones used for estimating the kinetic parameters. The model was able to accurately simulate simultaneous adsorption, desorption and photocatalytic degradation. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000384777200089 |
Publication Date |
2016-07-08 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947; 1873-3212 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.216 |
Times cited |
10 |
Open Access |
|
|
| |
Notes |
; J.V.W. acknowledges the Agentschap Innoveren & Ondernemen for a PhD fellowship. S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.216 |
|
| |
Call Number |
UA @ admin @ c:irua:139620 |
Serial |
5933 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Verbruggen, S.W.; Keulemans, M.; van Walsem, J.; Tytgat, T.; Lenaerts, S.; Denys, S. |
|
| |
Title |
CFD modeling of transient adsorption/desorption behavior in a gas phase photocatalytic fiber reactor |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
|
| |
Volume |
292 |
Issue |
|
Pages |
42-50 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
We present the use of computational fluid dynamics (CFD) for accurately determining the adsorption parameters of acetaldehyde on photocatalytic fiber filter material, integrated in a continuous flow system. Unlike the traditional analytical analysis based on Langmuir adsorption, not only steady-state situations but also transient phenomena can be accounted for. Air displacement effects in the reactor and gas detection cell are investigated and inherently made part of the model. Incorporation of a surface aldol condensation reaction in the CFD analysis further improves the accuracy of the model which enables to extract precise, intrinsic adsorption parameters for situations in which analytical analysis would otherwise fail. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000373648000005 |
Publication Date |
2016-02-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947; 1873-3212 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.216 |
Times cited |
12 |
Open Access |
|
|
| |
Notes |
; S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. M.K. acknowledges the IWT for a Ph.D. fellowship. Konstantina Kalafata and Ioanna Fasaki are greatly thanked for providing the NanoPhos suspension. Bioscience Engineering bachelor students M. Gerritsma, J. Helsen and Y. Riahi Drif are thanked for their assistance in performing the adsorption experiments. ; |
Approved |
Most recent IF: 6.216 |
|
| |
Call Number |
UA @ admin @ c:irua:130876 |
Serial |
5934 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Sóti, V.; Jacquet, N.; Apers, S.; Richel, A.; Lenaerts, S.; Cornet, I. |
|
| |
Title |
Monitoring the laccase reaction of vanillin and poplar hydrolysate |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Journal of chemical technology and biotechnology |
Abbreviated Journal |
J Chem Technol Biot |
|
| |
Volume |
91 |
Issue |
6 |
Pages |
1914-1922 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Biochemical Wastewater Valorization & Engineering (BioWaVE) |
|
| |
Abstract |
BACKGROUND Laccase is an intensively researched enzyme for industrial use. Except for decolorisation measurements, HPLC analysis is the conventional method for monitoring the phenolic removal during laccase enzyme reaction. This paper reports an investigation of the continuous UV absorbance follow-up of the laccase reaction with steam pretreated poplar hydrolysate. RESULTS Vanillin was used as a model substrate and lignocellulose xylose rich fraction (XRF) as a biologically complex substrate for laccase detoxification. The reaction was followed by HPLC-UV as well as by UV spectrometric measurements. Results suggest that the reaction can be successfully monitored by measuring the change of UV absorbance at 280 nm, without previous compound separation. In case of XRF experiments the spectrophotometric follow-up is especially useful, as HPLC analysis takes a long time and provides less information than in case of single substrates. The method seems to be suitable for optimization and process control. CONCLUSION The obtained results can help to construct a fast, easy and straightforward monitoring system for laccase-phenolic substrate reactions. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000375768300040 |
Publication Date |
2015-07-29 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0268-2575; 1097-4660 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.135 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
; This research is financed by the University of Antwerp (project number 15 FA100 002). ; |
Approved |
Most recent IF: 3.135 |
|
| |
Call Number |
UA @ admin @ c:irua:127694 |
Serial |
5972 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Spooren, J.; Kim, E.; Horckmans, L.; Broos, K.; Nielsen, P.; Quaghebeur, M. |
|
| |
Title |
In-situ chromium and vanadium recovery of landfilled ferrochromium and stainless steel slags |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
|
|
| |
Volume |
303 |
Issue |
|
Pages |
359-368 |
|
| |
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
A novel heap leaching method was investigated for selective removal of chromium (Cr) and-vanadium (V) from ferrochromium (FeCr) and stainless steel (SS) slags. In particular, alkaline oxidative heap leaching was simulated on lab-scale by batch and column leaching tests. The results show a selective leaching of Cr (11-19%) and V (7.0-7.5%) after 64 days of column leaching, with a very low dissolution (<2.2% (FeCr slag) and <0.15% (SS slag)) of matrix elements (e.g. Al, Fe, Si, Mg, Ca), when NaOCl is applied as oxidation agent and NaOH as alkaline agent. Furthermore, the used leaching liquor is reactive for a longer period of time, indicating that circulation of leaching liquor could be possible. Finally, the experimental results were fed into a first-order model which predicts that Cr will continue to leach from the tested slags for 4-5 years at a chosen infiltration rate of 73,000 l/(y m(2)). (C) 2016 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000383522800036 |
Publication Date |
2016-05-27 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947; 1873-3212 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UA @ admin @ c:irua:137104 |
Serial |
8074 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Kim, E.; Spooren, J.; Broos, K.; Nielsen, P.; Horckmans, L.; Vrancken, K.C.; Quaghebeur, M. |
|
| |
Title |
New method for selective Cr recovery from stainless steel slag by NaOCl assisted alkaline leaching and consecutive BaCrO4 precipitation |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
|
|
| |
Volume |
295 |
Issue |
|
Pages |
542-551 |
|
| |
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
A new hydrometallurgical method was investigated for selective leaching of chromium from stainless steel slag (SS slag) consisting of temperature controlled extraction with NaOH in the presence of NaOCl, followed by water leaching. After parameter optimization of the NaOCl-NaOH extraction step, a selective Cr leaching of 68% was reached, while dissolution of matrix materials was low (Al 0.3%, Ca 2.0%, Si 0.4%). The optimum conditions for the investigated system are: 105 degrees C, 6 h, SS slag particle size <63 mu m, mass ratio of NaOH to SS slag 0.13, and 3.3 mmol NaOCl to 1 g SS slag. The described oxidative alkaline leaching process by hypochlorite enables selective recovery of Cr at a significantly lower temperature and required amount of alkaline agent than molten salt or alkaline roasting processes. BaCrO4 was precipitated to purify and concentrate Cr from the leachate in which also minor amounts of Mn and V were present. This method allowed for a 99.9% Cr recovery rate. The obtained leaching residue shows no alterations of the SS slag's mineralogy with respect to untreated material. Therefore, a known carbonation treatment of the slag can be applied to prepare novel construction materials with a lowered Cr content. (C) 2016 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000375507300059 |
Publication Date |
2016-03-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947; 1873-3212 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
|
Times cited |
|
Open Access |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
UA @ admin @ c:irua:133632 |
Serial |
8302 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Tarasov, A.; Hu, Z.-Y.; Meledina, M.; Trusov, G.; Goodilin, E.; Van Tendeloo, G.; Dobrovolsky, Y. |
|
| |
Title |
One-Step Microheterogeneous Formation of Rutile@Anatase Core–Shell Nanostructured Microspheres Discovered by Precise Phase Mapping |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
121 |
Issue |
121 |
Pages |
4443-4450 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Nanostructured core−shell microspheres with a rough rutile core and a thin anatase shell are synthesized via a one-step heterogeneous templated hydrolysis process of TiCl4 vapor on the aerosol water−air interface. The rutile-in-anatase core−shell structure has been evidenced by different electron microscopy techniques, including electron energy-loss spectroscopy and 3D electron tomography. A new mechanism for the formation of a crystalline rutile core inside the anatase shell is proposed based on a statistical evaluation of a large number of electron microscopy data. We found that the control over the TiCl4 vapor pressure, the ratio between TiCl4 and H2O aerosol, and the reaction conditions plays a crucial role in the formation of the core−shell morphology and increases the yield of nanostructured microspheres. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000395616200038 |
Publication Date |
2017-03-02 |
|
| |
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 |
4 |
Open Access |
OpenAccess |
|
| |
Notes |
Z.-Y.H., M. M., and G.V.T. acknowledge support from the the EC Framework 7 program ESTEEM2 (Reference 312483). |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
EMAT @ emat @ c:irua:141720 |
Serial |
4472 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Matsubara, M.; Saniz, R.; Partoens, B.; Lamoen, D. |
|
| |
Title |
Doping anatase TiO2with group V-b and VI-b transition metal atoms: a hybrid functional first-principles study |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
19 |
Issue |
19 |
Pages |
1945-1952 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
We investigate the role of transition metal atoms of group V-b (V, Nb, Ta) and VI-b (Cr, Mo, W) as n- or p-type dopants in anatase TiO$2$ using thermodynamic
principles and density functional theory with the Heyd-Scuseria-Ernzerhof HSE06 hybrid functional. The HSE06 functional provides a realistic value for the band gap, which ensures a correct classification of dopants as shallow or deep donors or acceptors. Defect formation energies and thermodynamic transition levels are calculated taking into account the constraints imposed by the stability of TiO$2$ and the solubility limit of the impurities.
Nb, Ta, W and Mo are identified as shallow donors. Although W provides two electrons, Nb and Ta show a considerable lower formation energy, in particular under O-poor conditions. Mo donates in principle one electron, but under specific conditions can turn into a double donor. V impurities are deep donors and Cr
shows up as an amphoteric defect, thereby acting as an electron trapping center in n-type TiO$_2$ especially under O-rich conditions. A comparison with the available experimental data yields excellent agreement. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000394426400027 |
Publication Date |
2016-12-12 |
|
| |
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 |
19 |
Open Access |
OpenAccess |
|
| |
Notes |
We gratefully acknowledge financial support from the IWTVlaanderenthrough projects G.0191.08 and G.0150.13, and the BOF-NOI of the University of Antwerp. This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, which is funded by the Hercules foundation. M. M. acknowledges financial support from the GOA project ‘‘XANES meets ELNES’’ of the University of Antwerp. |
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
EMAT @ emat @ c:irua:140835 |
Serial |
4421 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Snoeckx, R.; Ozkan, A.; Reniers, F.; Bogaerts, A. |
|
| |
Title |
The Quest for Value-Added Products from Carbon Dioxide and Water in a Dielectric Barrier Discharge: A Chemical Kinetics Study |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
|
| |
Volume |
10 |
Issue |
10 |
Pages |
409-424 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Recycling of carbon dioxide by its conversion into value-added products has gained significant interest owing to the role it can play for use in an anthropogenic carbon cycle. The combined conversion with H2O could even mimic the natural photosynthesis process. An interesting gas conversion technique currently being considered in the field of CO2 conversion is plasma technology. To investigate whether it is also promising for this combined conversion, we performed a series of experiments and developed a chemical kinetics plasma chemistry model for a deeper understanding of the process. The main products formed were the syngas components CO and H2, as well as O2 and H2O2, whereas methanol formation was only observed in the parts-per-billion to parts-per-million range. The syngas ratio, on the other hand, could easily be controlled by varying both the water content and/or energy input. On the basis of the model, which was validated with experimental results, a chemical kinetics analysis was performed, which allowed the construction and investigation of the different pathways leading to the observed experimental results and which helped to clarify these results. This approach allowed us to evaluate this technology on the basis of its underlying chemistry and to propose solutions on how to further improve the formation of value-added products by using plasma technology. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000394571900012 |
Publication Date |
2016-11-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1864-5631 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
7.226 |
Times cited |
25 |
Open Access |
OpenAccess |
|
| |
Notes |
The authors acknowledge financial support from the Inter-university Attraction Pole (IAP; grant number IAP-VII/12, P7/34) program “PSI-Physical Chemistry of Plasma-Surface Interactions”, financially supported by the Belgian Federal Office for Science Policy (BELSPO), as well as the Fund for Scientific Research Flanders (FWO; grant number G.0066.12N). This work was performed 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. We also would like to thank the financial support given by “Fonds David et Alice Van Buuren”. Finally, we are very grateful to M. Kushner for providing the Global kin code, to T. Dufour for his support during the experiments, and to R. Aerts for his support during the model development. |
Approved |
Most recent IF: 7.226 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:139880 |
Serial |
4412 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. |
|
| |
Title |
Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
|
| |
Volume |
89 |
Issue |
89 |
Pages |
3326-3334 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
|
| |
Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
|
| |
Language |
|
Wos |
000397478300015 |
Publication Date |
2017-02-23 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0003-2700 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
|
| |
Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
|
| |
Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Tit, N.; Al Ezzi, M.M.; Abdullah, H.M.; Yusupov, M.; Kouser, S.; Bahlouli, H.; Yamani, Z.H. |
|
| |
Title |
Detection of CO2 using CNT-based sensors: Role of Fe catalyst on sensitivity and selectivity |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Materials chemistry and physics |
Abbreviated Journal |
Mater Chem Phys |
|
| |
Volume |
186 |
Issue |
186 |
Pages |
353-364 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
The adsorption of CO2 on surfaces of graphene and carbon nanotubes (CNTs), decorated with Fe atoms, are investigated using the self-consistent-charge density-functional tight-binding (SCC-DFTB) method, neglecting the heat effects. Fe ad-atoms are more stable when they are dispersed on hollow sites. They introduce a large density of states at the Fermi level (N-F); where keeping such density low would help in gas sensing. Furthermore, the Fe ad-atom can weaken the C=O double bonds of the chemisorbed CO2 molecule, paving the way for oxygen atoms to drain more charges from Fe. Consequently, chemisorption of CO2 molecules reduces both N-F and the conductance while it enhances the sensitivity with the increasing gas dose. Conducting armchair CNTs (ac-CNTs) have higher sensitivity than graphene and semiconducting zigzag CNTs (zz-CNT5). Comparative study of sensitivity of ac-CNT-Fe composite towards various gases (e.g., O-2, N-2, H-2, H2O, CO and CO2) has shown high sensitivity and selectivity towards CO, CO2 and H2O gases. (C) 2016 Elsevier B.V. All rights reserved. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
|
| |
Language |
|
Wos |
000390621200044 |
Publication Date |
2016-11-04 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0254-0584 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.084 |
Times cited |
17 |
Open Access |
Not_Open_Access |
|
| |
Notes |
|
Approved |
Most recent IF: 2.084 |
|
| |
Call Number |
UA @ lucian @ c:irua:140333 |
Serial |
4465 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Blommaerts, N.; Asapu, R.; Claes, N.; Bals, S.; Lenaerts, S.; Verbruggen, S.W. |
|
| |
Title |
Gas phase photocatalytic spiral reactor for fast and efficient pollutant degradation |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
|
| |
Volume |
316 |
Issue |
316 |
Pages |
850-856 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Sustainable Energy, Air and Water Technology (DuEL) |
|
| |
Abstract |
Photocatalytic reactors for the degradation of gaseous organic pollutants often suffer from major limitations such as small reaction area, sub-optimal irradiation conditions and thus limited reaction rate. In this work, an alternative solution is presented that involves a glass tube coated on the inside with (silvermodified) TiO2 and spiraled around a UVA lamp. First, the spiral reactor is coated from the inside with TiO2 using an experimentally verified procedure that is optimized toward UV light transmission. This procedure is kept as simple as possible and involves a single casting step of a 1 wt% suspension of TiO2 in ethanol through the spiral. This results in a coated tube that absorbs nearly all incident UV light under the experimental conditions used. The optimized coated spiral reactor is then benchmarked to a conventional annular photoreactor of the same outer dimensions and total catalyst loading over a broad range of experimental conditions. Although residence time distribution experiments indicate slightly longer dwelling of molecules in the spiral reactor, no significant difference in by-passing of gas between the spiral reactor and the annular reactor can be claimed. Acetaldehyde degradation efficiency of 100% is obtained with the spiral reactor for a residence time as low as 60 s, whereas the annular reactor could not achieve full degradation even at 1000 s residence time. In a final case study, addition of long-term stable silver nanoparticles, protected by an ultra-thin polymer shell applied via the layer-by-layer (LbL) method, to the spiral reactor coating is shown to double the degradation efficiency and provides an interesting strategy to cope with higher pollutant concentrations without changing the overall dimensions. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000398985200089 |
Publication Date |
2017-02-08 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.216 |
Times cited |
30 |
Open Access |
OpenAccess |
|
| |
Notes |
N.B. wishes to thank the University of Antwerp – Belgium for financial support. N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078- COLOURATOM). S.W.V. acknowledges the Research Foundation – Flanders (FWO) for a postdoctoral fellowship. (ROMEO:green; preprint:; postprint:can ; pdfversion:cannot); ecas_sara |
Approved |
Most recent IF: 6.216 |
|
| |
Call Number |
EMAT @ emat @ c:irua:140925UA @ admin @ c:irua:140925 |
Serial |
4481 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J. |
|
| |
Title |
Synthesis of MAX Phases in the Zr-Ti-Al-C System |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
56 |
Issue |
56 |
Pages |
3489-3498 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000397171100045 |
Publication Date |
2017-03-20 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
26 |
Open Access |
OpenAccess |
|
| |
Notes |
Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; |
Approved |
Most recent IF: 4.857 |
|
| |
Call Number |
EMAT @ emat @ c:irua:141794 |
Serial |
4491 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
van der Stam, W.; Geuchies, J.J.; Altantzis, T.; van den Bos, K.H.W.; Meeldijk, J.D.; Van Aert, S.; Bals, S.; Vanmaekelbergh, D.; de Mello Donega, C. |
|
| |
Title |
Highly Emissive Divalent-Ion-Doped Colloidal CsPb1–xMxBr3Perovskite Nanocrystals through Cation Exchange |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
|
| |
Volume |
139 |
Issue |
139 |
Pages |
4087-4097 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic
anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1−xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 < x ≤ 0.1), with preservation of the original NC shape. The size of the parent NCs is also preserved in the product NCs, apart from a small (few
%) contraction of the unit cells upon incorporation of the guest cations. The partial Pb2+ for M2+ exchange leads to a blue-shift of the optical spectra, while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known
system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000397477700027 |
Publication Date |
2017-03-10 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0002-7863 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
13.858 |
Times cited |
535 |
Open Access |
OpenAccess |
|
| |
Notes |
W.v.d.S. and C.d.M.D. acknowledge financial support from the division of Chemical Sciences (CW) of The Netherlands Organization for Scientific Research (NWO) under grant number ECHO.712.012.001. J.J.G. and D.V. acknowledge financial support from the Debye Graduate program. S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS). K.H.W.v.d.B., S.B., S.V.A. and T.A. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0368.15N, G.0369.15N), a Ph.D. grant to K.H.W.v.d.B, and a postdoctoral research grant to T.A. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 13.858 |
|
| |
Call Number |
EMAT @ emat @ c:irua:141754UA @ admin @ c:irua:141754 |
Serial |
4482 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Batuk, D.; Batuk, M.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Tyablikov, O.A.; Hadermann, J.; Abakumov, A.M. |
|
| |
Title |
Crystal Structure, Defects, Magnetic and Dielectric Properties of the Layered Bi3n+1Ti7Fe3n-3,O9n+11 Perovskite-Anatase lntergrowths |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
| |
Volume |
56 |
Issue |
56 |
Pages |
931-942 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The Bi3n+1Ti7Fe3n-3,O9n+11 materials are built of (001)(p) plane parallel perovskite blocks with a thickness of n (Ti,Fe)O-6 octahedra, separated by periodic translational interfaces. The interfaces are based on anatase-like chains of edge -sharing (Ti,Fe)O-6 octahedra. Together with the octahedra of the perovskite blocks, they create S-shaped tunnels stabilized by lone pair Bi3+ cations. In this work, the structure of the n = 4-6 Bi3n+1Ti7Fe3n-3,O9n+11 homologues is analyzed in detail using advanced transmission electron microscopy, powder X-ray diffraction, and Mossbauer spectroscopy. The connectivity of the anatase-like chains to the perovskite blocks results in,a 3ap periodicity along the interfaces, so that they can be located either on top of each other or with shifts of +/- a(p) along [100](p). The ordered arrangement of the interfaces gives rise to orthorhombic Immm and monoclinic A2/m polymorphs with the unit cell parameters a = 3a(p), b = b(p), c = 2(n + 1)c(p) and a = 3a(p), b = b(p), c = 2(n + 1)c(p) – a(p), respectively. While the n = 3 compound is orthorhombic, the monoclinic modification is more favorable in higher homologues. The Bi3n+1Ti7Fe3n-3,O9n+11 structures demonstrate intricate patterns of atomic displacements in the perovskite blocks, which are supported by the stereochemical activity of the Bi3+ cations. These patterns are coupled to the cationic coordination of the oxygen atoms in the (Ti,Fe)O-2 layers at the border of the perovskite blocks. The coupling is strong in the 1/ = 3, 4 homologues, but gradually reduces with the increasing thickness of the perovskite blocks, so that, in the n = 6 compound, the dominant mode of atomic displacements is aligned along the interface planes. The displacements in the adjacent perovskite blocks tend to order antiparallel, resulting in an overall antipolar structure. The Bi3n+1Ti7Fe3n-3,O9n+11 materials demonstrate an unusual diversity of structure defects. The n = 4-6 homologues are robust antiferromagnets below T-N = 135, 220, and 295 K, respectively. They show a high dielectric constant that weakly increases with temperature and is relatively insensitive to the Ti/Fe ratio. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
|
| |
Language |
|
Wos |
000392262400029 |
Publication Date |
2016-12-25 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
| |
Notes |
; The work was supported by the Russian Science Foundation (grant 14-13-00680). ; |
Approved |
Most recent IF: 4.857 |
|
| |
Call Number |
UA @ lucian @ c:irua:141471 |
Serial |
4495 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Martens, J.A.; Bogaerts, A.; De Kimpe, N.; Jacobs, P.A.; Marin, G.B.; Rabaey, K.; Saeys, M.; Verhelst, S. |
|
| |
Title |
The Chemical Route to a Carbon Dioxide Neutral World |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
|
| |
Volume |
10 |
Issue |
10 |
Pages |
1039-1055 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Excessive CO2 emissions in the atmosphere from anthropogenic activity can be divided into point sources and diffuse sources. The capture of CO2 from flue gases of large industrial installations and its conversion into fuels and chemicals with fast catalytic processes seems technically possible. Some emerging technologies are already being demonstrated on an industrial scale. Others are still being tested on a laboratory or pilot scale. These emerging chemical technologies can be implemented in a time window ranging from 5 to 20 years. The massive amounts of energy needed for capturing processes and the conversion of CO2 should come from low-carbon energy sources, such as tidal, geothermal, and nuclear energy, but also, mainly, from the sun. Synthetic methane gas that can be formed from CO2 and hydrogen gas is an attractive renewable energy carrier with an existing distribution system. Methanol offers advantages as a liquid fuel and is also a building block for the chemical industry. CO2 emissions from diffuse sources is a difficult problem to solve, particularly for CO2 emissions from road, water, and air transport, but steady progress in the development of technology for capturing CO2 from air is being made. It is impossible to ban carbon from the entire energy
supply of mankind with the current technological knowledge, but a transition to a mixed carbon–hydrogen economy can reduce net CO2 emissions and ultimately lead to a CO2-neutral world. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000398182800002 |
Publication Date |
2017-02-24 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1864-5631 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
7.226 |
Times cited |
75 |
Open Access |
OpenAccess |
|
| |
Notes |
This paper is written by members of the Royal Flemish Academy of Belgium for Science and the Arts (KVAB) and external experts. KVAB is acknowledged for supporting the writing and publishing of this viewpoint. Valuable suggestions made by colleagues Jan Kretzschmar, Stan Ulens, and Luc Sterckx are highly appreciated. Special thanks go to Mr. Bert Seghers and Mrs. N. Boelens of KVAB for practical assistance. Mr. Tim Lacoere is acknowledged for graphic design and layout of the figures, and Steven Heylen and Elke Verheyen are acknowledged for data collection and editorial assistance. |
Approved |
Most recent IF: 7.226 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:141916 |
Serial |
4532 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Verlackt, C.C.W.; Van Boxem, W.; Dewaele, D.; Lemière, F.; Sobott, F.; Benedikt, J.; Neyts, E.C.; Bogaerts, A. |
|
| |
Title |
Mechanisms of Peptide Oxidation by Hydroxyl Radicals: Insight at the Molecular Scale |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
121 |
Issue |
121 |
Pages |
5787-5799 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Molecular dynamics (MD) simulations were performed to provide atomic scale insight in the initial interaction between hydroxyl radicals (OH) and peptide systems in solution. These OH radicals are representative reactive oxygen species produced by cold atmospheric plasmas. The use of plasma for biomedical applications is gaining increasing interest, but the fundamental mechanisms behind the plasma modifications still remain largely elusive. This study helps to gain more insight in the underlying mechanisms of plasma medicine but is also more generally applicable to peptide oxidation, of interest for other applications. Combining both reactive and nonreactive MD simulations, we are able to elucidate the reactivity of the amino acids inside the peptide systems and their effect on their structure up to 1 μs. Additionally, experiments were performed, treating the simulated peptides with a plasma jet. The computational results presented here correlate well with the obtained experimental data and highlight the importance of the chemical environment for the reactivity of the individual amino acids, so that specific amino acids are attacked in higher numbers than expected. Furthermore, the long time scale simulations suggest that a single oxidation has an effect on the 3D conformation due to an increase in hydrophilicity and intra- and intermolecular interactions. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000396969900037 |
Publication Date |
2017-03-16 |
|
| |
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 |
5 |
Open Access |
OpenAccess |
|
| |
Notes |
Fonds Wetenschappelijk Onderzoek, G012413N ; |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:142202 |
Serial |
4537 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mernissi Cherigui, E.A.; Sentosun, K.; Bouckenooge, P.; Vanrompay, H.; Bals, S.; Terryn, H.; Ustarroz, J. |
|
| |
Title |
A Comprehensive Study of the Electrodeposition of Nickel Nanostructures from Deep Eutectic Solvents: Self-Limiting Growth by Electrolysis of Residual Water |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
121 |
Issue |
121 |
Pages |
9337-9347 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
The electrodeposition of nickel nanostructures on glassy carbon was investigated in 1:2 choline chloride – urea (1:2 ChCl-U) deep eutectic solvent (DES). By combining electrochemical techniques with ex-situ FE-SEM, XPS, HAADF-STEM and EDX, the electrochemical processes occurring during nickel deposition were better understood. Special attention was given to the interaction between the solvent and the growing nickel nanoparticles. The application of a suffciently negative potential results into the electrocatlytic hydrolisis of residual water in the DES, which leads to the formation of a mixed layer of Ni/Ni(OH)2(ads). In addition, hydrogen bonds between hydroxide species and the DES components could be formed, quenching the growth of the nickel clusters favouring their aggregation. Due to these processes, a highly dense distribution of nickel nanostructures can be obtained within a wide potential range. Understanding the role of residual water and the interactions at the interface during metal electrodeposition from DESs is essential to produce supported nanostructures in a controllable way for a broad range of applications and technologies. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000400881100027 |
Publication Date |
2017-04-12 |
|
| |
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 |
66 |
Open Access |
OpenAccess |
|
| |
Notes |
E.A. Mernissi Cherigui acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, research project G019014N). S. Bals acknowledges funding from the European Research Council (Starting Grant No. COLOURATOMS 335078). H.V. gratefully acknowledges financial support by the Flemish Fund for Scientifi c Research (FWO Vlaanderen). Finally, J. Ustarroz acknowledges funding from the Fonds Wetenschappelijk Onderzoek in Flanders (FWO, postdoctoral grant 12I7816N). (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
EMAT @ emat @ c:irua:142208UA @ admin @ c:irua:142208 |
Serial |
4551 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Berdiyorov, G.R.; Neek-Amal, M.; Hussein, I.A.; Madjet, M.E.; Peeters, F.M. |
|
| |
Title |
Large CO2 uptake on a monolayer of CaO |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
|
| |
Volume |
5 |
Issue |
5 |
Pages |
2110-2114 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Density functional theory calculations are used to study gas adsorption properties of a recently synthesized CaO monolayer, which is found to be thermodynamically stable in its buckled form. Due to its topology and strong interaction with the CO2 molecules, this material possesses a remarkably high CO2 uptake capacity (similar to 0.4 g CO2 per g adsorbent). The CaO + CO2 system shows excellent thermal stability (up to 1000 K). Moreover, the material is highly selective towards CO2 against other major greenhouse gases such as CH4 and N2O. These advantages make this material a very promising candidate for CO2 capture and storage applications. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
|
| |
Language |
|
Wos |
000395074300035 |
Publication Date |
2016-12-19 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2050-7488; 2050-7496 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
8.867 |
Times cited |
2 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 8.867 |
|
| |
Call Number |
UA @ lucian @ c:irua:142034 |
Serial |
4556 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Khalilov, U.; Bogaerts, A.; Neyts, E.C. |
|
| |
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 |
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 |
Berthelot, A.; Bogaerts, A. |
|
| |
Title |
Modeling of CO2Splitting in a Microwave Plasma: How to Improve the Conversion and Energy Efficiency |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
|
| |
Volume |
121 |
Issue |
121 |
Pages |
8236-8251 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Microwave plasmas are one of the most promising techniques for CO2 conversion into value-added chemicals and fuels since they are very energy efficient. Nevertheless, experiments show that this high energy efficiency is only reached at low pressures and significantly drops toward atmospheric pressure, which is a clear limitation for industrial applications. In this paper, we use a zerodimensional reaction kinetics model to simulate a CO2 microwave plasma in a pressure range from 50 mbar to 1 bar, in order to evaluate the reasons for this decrease in energy efficiency at atmospheric pressure. The code includes a detailed description of the vibrational kinetics of CO2, CO, and O2 as well as the energy exchanges between them because the vibrational kinetics is known to be crucial for energy efficient CO2 splitting. First, we use a self-consistent gas temperature calculation in order to assess the key performance indicators for CO2 splitting, i.e., the CO2 conversion and corresponding energy efficiency. Our results indicate that lower pressures and higher power densities lead to more vibrational excitation, which is beneficial for the conversion. We also demonstrate the key role of the gas temperature. The model predicts the highest conversion and energy efficiencies at pressures around 300 mbar, which is in agreement with experiments from the literature. We also show the beneficial aspect of fast gas cooling in the afterglow at high pressure. In a second step, we study in more detail the effects of pressure, gas temperature, and power density on the vibrational distribution function and on the dissociation and recombination mechanisms of CO2, which define the CO2 splitting efficiency. This study allows us to identify the limiting factors of CO2 conversion and to propose potential solutions to improve the process. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000400039300002 |
Publication Date |
2017-04-20 |
|
| |
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 |
47 |
Open Access |
OpenAccess |
|
| |
Notes |
Federaal Wetenschapsbeleid; |
Approved |
Most recent IF: 4.536 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:142809 |
Serial |
4567 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Peters, J.L.; van den Bos, K.H.W.; Van Aert, S.; Goris, B.; Bals, S.; Vanmaekelbergh, D. |
|
| |
Title |
Ligand-Induced Shape Transformation of PbSe Nanocrystals |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
|
| |
Volume |
29 |
Issue |
29 |
Pages |
4122-4128 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
We present a study of the relation between the surface chemistry and nanocrystal shape of PbSe nanocrystals with a variable Pb-to-Se stoichiometry and density of oleate ligands. The oleate ligand density and binding configuration are monitored by nuclear magnetic resonance and Fourier transform infrared absorbance spectroscopy, allowing us to quantify the number of surface-attached ligands per NC and the nature of the surface−Pb−oleate configuration. The three-dimensional shape of the PbSe nanocrystals is obtained from high-angle annular dark field scanning transmission electron microscopy combined with an atom counting method. We show that the enhanced oleate capping results in a stabilization and extension of the {111} facets, and a crystal shape transformation from a truncated nanocube to a truncated octahedron. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000401221700034 |
Publication Date |
2017-05-09 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
9.466 |
Times cited |
45 |
Open Access |
OpenAccess |
|
| |
Notes |
D.V. acknowledges the European Research Council, ERC advanced grant, Project 692691-First Step, for financial support. We also acknowledge the Dutch FOM programme “Designing Dirac carriers in honeycomb semiconductor superlattices” (FOM Program 152) for financial support. The authors gratefully acknowledge funding from the Research Foundation Flanders (G.036915, G.037413, and funding of a Ph.D. research grant to K.H.W.v.d.B. and a postdoctoral grant to B.G.). S.B. acknowledges the European Research Council, ERC Grant 335078-Colouratom. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ECAS_Sara |
Approved |
Most recent IF: 9.466 |
|
| |
Call Number |
EMAT @ emat @ c:irua:143750 c:irua:142983UA @ admin @ c:irua:143750 |
Serial |
4571 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wang, W.; Patil, B.; Heijkers, S.; Hessel, V.; Bogaerts, A. |
|
| |
Title |
Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling |
Type |
A1 Journal Article |
| |
Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
|
| |
Volume |
10 |
Issue |
10 |
Pages |
2110-2110 |
|
| |
Keywords |
A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
|
| |
Abstract |
The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2/O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx. The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber–Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which lowtemperature plasma technology might play an important role. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
|
Publication Date |
2017-05-11 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1864-5631 |
ISBN |
|
Additional Links |
|
|
| |
Impact Factor |
7.226 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
This research was supported by the European Marie Skłodowska- Curie Individual Fellowship “GlidArc” within Horizon 2020 (Grant No.657304), by the FWO project (grant G.0383.16 N) and by the EU project MAPSYN: Microwave, Acoustic and Plasma assisted SYNthesis, under the grant agreement no. CP-IP 309376 of the European Community’s Seventh Framework Program. The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. |
Approved |
Most recent IF: 7.226 |
|
| |
Call Number |
PLASMANT @ plasmant @ |
Serial |
4573 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Saniz, R.; Bekaert, J.; Partoens, B.; Lamoen, D. |
|
| |
Title |
Structural and electronic properties of defects at grain boundaries in CuInSe2 |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
|
| |
Volume |
19 |
Issue |
19 |
Pages |
14770-14780 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
|
| |
Abstract |
We report on a first-principles study of the structural and electronic properties of a Sigma3 (112) grain boundary model in CuInSe2. The study focuses on a coherent, stoichiometry preserving, cation–Se terminated grain boundary, addressing the properties of the grain boundary as such, as well as the effect
of well known defects in CuInSe2. We show that in spite of its apparent simplicity, such a grain boundary exhibits a very rich phenomenology, providing an explanation for several of the experimentally observed properties of grain boundaries in CuInSe2 thin films. In particular, we show that the combined effect of Cu vacancies and cation antisites can result in the observed Cu depletion with no In enrichment at the grain boundaries. Furthermore, Cu vacancies are unlikely to produce a hole barrier at the grain boundaries, but Na may indeed have such an effect. We find that Na-on-Cu defects will tend to form abundantly at
the grain boundaries, and can provide a mechanism for the carrier depletion and/or type inversion experimentally reported. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000403327200059 |
Publication Date |
2017-05-12 |
|
| |
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 |
12 |
Open Access |
OpenAccess |
|
| |
Notes |
We thank B. Schoeters for his assistance running the GBstudio software. We acknowledge the financial support of FWO-Vlaanderen through project G.0150.13. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by FWO-Vlaanderen and the Flemish Government-department EWI. |
Approved |
Most recent IF: 4.123 |
|
| |
Call Number |
EMAT @ emat @ c:irua:143869 |
Serial |
4577 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ben Hafsia, A.; Hendrickx, M.; Batuk, M.; Khitouni, M.; Hadermann, J.; Greneche, J.-M.; Rammeh, N. |
|
| |
Title |
Crystal structure study of manganese and titanium substituted BaLaFe2O6-δ |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of solid state chemistry |
Abbreviated Journal |
J Solid State Chem |
|
| |
Volume |
251 |
Issue |
251 |
Pages |
186-193 |
|
| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
| |
Abstract |
Barium lanthanum ferrite and four Mn/Ti substituted materials were synthesized by the sol-gel method. The crystal structure of the materials was studied by a combination of X-ray powder diffraction, electron diffraction, scanning transmission electron microscopy and 57Fe Mössbauer spectrometry. BaLaFe2O6-δ has a cubic perovskite structure and Ba0.7La1.3FeMnO6-δ is distorted perovskite with the R-3c symmetry, both from electron diffraction and X-ray powder diffraction. However, according to transmission electron microscopy, the crystals of BaLaFeTiO6-δ, BaLaFeTi0.5Mn0.5O6-δ, and BaLaFe0.5Ti0.5MnO6-δ consist of nanodomains with different symmetries (Pm3m next to R-3c due to octahedral tilts), whereas the bulk X-ray powder diffraction patterns for these compounds correspond to the simple cubic structure. 57Fe Mössbauer spectrometry confirms that all materials contain high spin state Fe3+ ions which are strongly influenced by the chemical disorder
resulting from various cationic environments. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000402581200024 |
Publication Date |
2017-04-20 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-4596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.299 |
Times cited |
|
Open Access |
Not_Open_Access |
|
| |
Notes |
This study has been supported by the Tunisian Ministry of Higher Education and Scientific Research and by the University of Antwerp BOF Grant 33024 funding scheme. |
Approved |
Most recent IF: 2.299 |
|
| |
Call Number |
EMAT @ emat @ c:irua:143988 |
Serial |
4582 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Wang, W.; Mei, D.; Tu, X.; Bogaerts, A. |
|
| |
Title |
Gliding arc plasma for CO 2 conversion: Better insights by a combined experimental and modelling approach |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
|
| |
Volume |
330 |
Issue |
|
Pages |
11-25 |
|
| |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
A gliding arc plasma is a potential way to convert CO2 into CO and O2, due to its non-equilibrium character, but little is known about the underlying mechanisms. In this paper, a self-consistent two-dimensional (2D) gliding arc model is developed, with a detailed non-equilibrium CO2 plasma chemistry, and validated with experiments. Our calculated values of the electron number density in the plasma, the CO2 conversion and energy efficiency show reasonable agreement with the experiments, indicating that the model can provide a realistic picture of the plasma chemistry. Comparison of the results with classical thermal conversion, as well as other plasma-based technologies for CO2 conversion reported in literature, demonstrates the non-equilibrium character of the gliding arc, and indicates that the gliding arc is a promising plasma reactor for CO2 conversion. However, some process modifications should be exploited to further improve its performance. As the model provides a realistic picture of the plasma behaviour, we use it first to investigate the plasma characteristics in a whole gliding arc cycle, which is necessary to understand the underlying mechanisms. Subsequently, we perform a chemical kinetics analysis, to investigate the different pathways for CO2 loss and formation. Based on the revealed discharge properties and the underlying CO2 plasma chemistry, the model allows us to propose solutions on how to further improve the
CO2 conversion and energy efficiency by a gliding arc plasma. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000414083300002 |
Publication Date |
2017-07-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.216 |
Times cited |
38 |
Open Access |
OpenAccess |
|
| |
Notes |
This research was supported by the European Marie Skłodowska- Curie Individual Fellowship “GlidArc” within Horizon 2020 (Grant No. 657304) and by the FWO project (grant G.0383.16N). The support of this experimental work by the EPSRC CO2Chem Seedcorn Grant and the FWO travel grant for study abroad (Grant K2.128.17N) is gratefully acknowledged. The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. |
Approved |
Most recent IF: 6.216 |
|
| |
Call Number |
PLASMANT @ plasmant @c:irua:145033 |
Serial |
4636 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ramakers, M.; Trenchev, G.; Heijkers, S.; Wang, W.; Bogaerts, A. |
|
| |
Title |
Gliding Arc Plasmatron: Providing an Alternative Method for Carbon Dioxide Conversion |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
|
| |
Volume |
10 |
Issue |
10 |
Pages |
2642-2652 |
|
| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Low-temperature plasmas are gaining a lot of interest for environmental and energy applications. A large research field in these applications is the conversion of CO2 into chemicals and fuels. Since CO2 is a very stable molecule, a key performance indicator for the research on plasma-based CO2 conversion is the energy efficiency. Until now, the energy efficiency in atmospheric plasma reactors is quite low, and therefore we employ here a novel type of plasma reactor, the gliding arc plasmatron (GAP). This paper provides a detailed experimental and computational study of the CO2 conversion, as well as the energy cost and efficiency in a GAP. A comparison with thermal conversion, other plasma types and other novel CO2 conversion technologies is made to find out whether this novel plasma reactor can provide a significant contribution to the much-needed efficient conversion of CO2. From these comparisons it becomes evident that our results are less than a factor of two away from being cost competitive and already outperform several other new technologies. Furthermore, we indicate how the performance of the GAP can still be improved by further exploiting its non-equilibrium character. Hence, it is clear that the GAP is very promising for CO2 conversion. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000403934400014 |
Publication Date |
2017-05-22 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1864-5631 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
7.226 |
Times cited |
42 |
Open Access |
OpenAccess |
|
| |
Notes |
Federaal Wetenschapsbeleid; Fonds Wetenschappelijk Onderzoek, G.0383.16N 11U5316N ; Horizon 2020, 657304 ; |
Approved |
Most recent IF: 7.226 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:144184 |
Serial |
4616 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Michielsen, I.; Uytdenhouwen, Y.; Pype, J.; Michielsen, B.; Mertens, J.; Reniers, F.; Meynen, V.; Bogaerts, A. |
|
| |
Title |
CO 2 dissociation in a packed bed DBD reactor: First steps towards a better understanding of plasma catalysis |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
|
| |
Volume |
326 |
Issue |
326 |
Pages |
477-488 |
|
| |
Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
|
| |
Abstract |
Plasma catalysis is gaining increasing interest for CO2 conversion, but the interaction between the plasma and catalyst is still poorly understood. This is caused by limited systematic materials research, since most works combine a plasma with commercial supported catalysts and packings. In the present paper, we study the influence of specific material and reactor properties, as well as reactor/bead configuration, on the conversion and energy efficiency of CO2 dissociation in a packed bed dielectric barrier discharge (DBD) reactor. Of the various packing materials investigated, BaTiO3 yields the highest conversion and energy efficiency, i.e., 25% and 4.5%.
Our results show that, when evaluating the influence of catalysts, the impact of the packing (support) material itself cannot be neglected, since it can largely affect the conversion and energy efficiency. This shows the large potential for further improvement of packed bed plasma reactors for CO2 conversion and other chemical conversion reactions by adjusting both packing (support) properties and catalytically active sites. Moreover, we clearly prove that comparison of results obtained in different reactor setups should be done with care, since there is a large effect of the reactor setup and reactor/bead configuration. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Wos |
000406137200047 |
Publication Date |
2017-06-01 |
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1385-8947 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.216 |
Times cited |
49 |
Open Access |
OpenAccess |
|
| |
Notes |
This research was carried out with financial support of the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT Flanders) for both I. Michielsen (IWT-141093) and J. Pype (IWT-131229) and of the Walloon region through the excellence programme FLYCOAT (nr. 1318147) for the profilometry measurements. The authors also acknowledge financial support from an IOF-SBO project from the University of Antwerp and from the Fund for Scientific Research (FWO; grant number: G.0254.14 N). This research was carried out in the framework of the network on Physical Chemistry of Plasma-Surface Interactions – Interuniversity Attraction Poles, phase VII (http://psi-iap7.ulb. ac.be/), and supported by the Belgian Science Policy Office (BELSPO). The authors would also like to thank Koen Van Laer for the discussions on this manuscript. |
Approved |
Most recent IF: 6.216 |
|
| |
Call Number |
PLASMANT @ plasmant @ c:irua:144802 |
Serial |
4626 |
|
| Permanent link to this record |
