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Author Marchetti, A.; Saniz, R.; Krishnan, D.; Rabbachin, L.; Nuyts, G.; De Meyer, S.; Verbeeck, J.; Janssens, K.; Pelosi, C.; Lamoen, D.; Partoens, B.; De Wael, K.
Title Unraveling the Role of Lattice Substitutions on the Stabilization of the Intrinsically Unstable Pb2Sb2O7Pyrochlore: Explaining the Lightfastness of Lead Pyroantimonate Artists’ Pigments Type A1 Journal article
Year 2020 Publication Chemistry Of Materials Abbreviated Journal Chem Mater
Volume 32 Issue 7 Pages 2863-2873
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract The pyroantimonate pigments Naples yellow and lead tin antimonate yellow are recognized as some of the most stable synthetic yellow pigments in the history of art. However, this exceptional lightfastness is in contrast with experimental evidence suggesting that this class of mixed oxides is of semiconducting nature. In this study the electronic structure and light-induced behavior of the lead pyroantimonate pigments were determined by means of a combined multifaceted analytical and computational approach (photoelectrochemical measurements, UV-vis diffuse reflectance spectroscopy, STEM-EDS, STEM-HAADF, and density functional theory calculations). The results demonstrate both the semiconducting nature and the lightfastness of these pigments. Poor optical absorption and minority carrier mobility are the main properties responsible for the observed stability. In addition, novel fundamental insights into the role played by Na atoms in the stabilization of the otherwise intrinsically unstable Pb2Sb2O7 pyrochlore were obtained.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000526394000016 Publication Date 2020-04-14
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 8.6 Times cited 8 Open Access OpenAccess
Notes (up) Universiteit Antwerpen; Belgian Federal Science Policy Office; Approved Most recent IF: 8.6; 2020 IF: 9.466
Call Number EMAT @ emat @c:irua:168819 Serial 6363
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Author van der Stam, W.; Gradmann, S.; Altantzis, T.; Ke, X.; Baldus, M.; Bals, S.; de Mello Donega, C.
Title Shape Control of Colloidal Cu2-x S Polyhedral Nanocrystals by Tuning the Nucleation Rates Type A1 Journal article
Year 2016 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 28 Issue 28 Pages 6705-6715
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Synthesis protocols for colloidal nanocrystals (NCs) with narrow size and shape distributions are of particular interest for the successful implementation of these nanocrystals into devices. Moreover, the preparation of NCs with well-defined crystal phases is of key importance. In this work, we show that Sn(IV)-thiolate complexes formed in situ strongly influence the nucleation and growth rates of colloidal Cu2-x S polyhedral NCs, thereby dictating their final size, shape, and crystal structure. This allowed us to successfully synthesize hexagonal bifrustums and hexagonal bipyramid NCs with low-chalcocite crystal structure, and hexagonal nanoplatelets with various thicknesses and aspect ratios with the djurleite crystal structure, by solely varying the concentration of Sn(IV)-additives (namely, SnBr4) in the reaction medium. Solution and solid-state 119Sn NMR measurements show that SnBr4 is converted in situ to Sn(IV)-thiolate complexes, which increase the Cu2-x S nucleation barrier without affecting the precursor conversion rates. This influences both the nucleation and growth rates in a concentration-dependent fashion and leads to a better separation between nucleation and growth. Our approach of tuning the nucleation and growth rates with in situ-generated Sn-thiolate complexes might have a more general impact due to the availability of various metal-thiolate complexes, possibly resulting in polyhedral NCs of a wide variety of metal-sulfide compositions.
Address Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University , P.O. Box 80000, 3508 TA Utrecht, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Wos 000384399000037 Publication Date 2016-09-02
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 27 Open Access OpenAccess
Notes (up) 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. M.B. also gratefully acknowledges NWO for funding the NMR infrastructure (Middle Groot program, grant number 700.58.102). S.B. acknowledges financial support from the European Research Council (ERC Starting Grant # 335078-COLOURATOMS).; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); Approved Most recent IF: 9.466
Call Number EMAT @ emat @ c:irua:135928 Serial 4285
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Author Shetty, S.; Sinha, S.K.; Ahmad, R.; Singh, A.K.; Van Tendeloo, G.; Ravishankar, N.
Title Existence of Ti2+States on the Surface of Heavily Reduced SrTiO3Nanocubes Type A1 Journal article
Year 2017 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume Issue Pages acs.chemmater.7b04113
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Using advanced electron microscopy, we demonstrate the presence of Ti2+ on the 001 surfaces of heavily reduced strontium titanate nanocubes. While high-angle annular dark field images show a clear difference between the surfaces of the unreduced and reduced samples, electron energy loss spectroscopy detects the presence of Ti2+ on the surface of the reduced cubes. Conventional reduction only leads to the formation of Ti3+ and involves the use of high temperatures. In our case, reduction is achieved at relatively lower temperatures in the solid state using sodium borohydride as the reducing agent. Our findings provide insights into the optical properties of the samples and provide a convenient method to produce highly reduced surfaces that could demonstrate a range of exotic physical phenomena
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000418206600005 Publication Date 2017-11-17
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 8 Open Access OpenAccess
Notes (up) We thank Advanced Facility for Microscopy and Microanalysis (AFMM), IISc, Bangalore for providing the TEM facility. We also thank MNCF, CeNSE, IISc for providing the XPS and FT-IR facilities. We acknowledge the help from Prof. Anshu Pandey for providing the PL facility and Mr. Ashutosh Gupta for the help with measurements. SS and NR thank DST for providing the financial support. RA and AKS acknowledge Super Computing Education and Research Center (SERC) and Materials Research Center (MRC), at IISc for providing required computational facilities. RA acknowledges the financial support from INSPIRE fellowship, AORC.Science and Engineering Research Board; Federaal Wetenschapsbeleid; Department of Science and Technology, Ministry of Science and Technology; Approved Most recent IF: 9.466
Call Number UA @ lucian @c:irua:147191 Serial 4767
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