The Structure and Chemical Composition of the Cr and Fe Pyrolytic Coatings on the MWCNTs’ Surface According to NEXAFS and XPS Spectroscopy
| Autor: | Olga V. Petrova, Roman N. Skandakov, S. V. Nekipelov, Danil V. Sivkov, A. M. Ob’edkov, S. I. Isaenko, S. A. Gusev, V. N. Sivkov, Ilya Vilkov, Dmitriy Bogachuk, B. S. Kaverin, A E Mingaleva |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
General Chemical Engineering Oxide 02 engineering and technology Carbon nanotube Chemical vapor deposition 010402 general chemistry 01 natural sciences Article law.invention lcsh:Chemistry NEXAFS chemistry.chemical_compound X-ray photoelectron spectroscopy law (pyrolytic Cr)/MWCNTs XPS General Materials Science Pyrolytic carbon total electron yield (pyrolytic Fe)/MWCNTs nanocomposite multi-walled carbon nanotubes 021001 nanoscience & nanotechnology XANES 0104 chemical sciences Iron pentacarbonyl lcsh:QD1-999 chemistry Chemical engineering MOCVD Chemical binding 0210 nano-technology |
| Zdroj: | Nanomaterials Volume 10 Issue 2 Nanomaterials, Vol 10, Iss 2, p 374 (2020) |
| ISSN: | 2079-4991 |
| Popis: | The paper is devoted to the structure and properties of the composite material based on multi-walled carbon nanotubes (MWCNTs) covered with pyrolytic iron and chromium. Fe/MWCNTs and Cr/MWCNTs nanocomposites have been prepared by the metal organic chemical vapor deposition (MOCVD) growth technique using iron pentacarbonyl and bis(arene)chromium compounds, respectively. Composites structures and morphologies preliminary study were performed using X-ray diffraction, scanning and transmission electron microscopy and Raman scattering. The atomic and chemical composition of the MWCNTs&rsquo surface, Fe-coating and Cr-coating and interface&mdash (MWCNTs surface)/(metal coating) were studied by total electron yield method in the region of near-edge X-ray absorption fine structure (NEXAFS) C1s, Fe2p and Cr2p absorption edges using synchrotron radiation of the Russian-German dipole beamline (RGBL) at BESSY-II and the X-ray photoelectron spectroscopy (XPS) method using the ESCALAB 250 Xi spectrometer and charge compensation system. The absorption cross sections in the NEXAFS C1s edge of the nanocomposites and MWCNTs were measured using the developed approach of suppressing and estimating the contributions of the non-monochromatic background and multiple reflection orders radiation from the diffraction grating. The efficiency of the method was demonstrated by the example of the Cr/MWCNT nanocomposite, since its Cr2p NEXAFS spectra contain additional C1s NEXAFS in the second diffraction order. The study has shown that the MWCNTs&rsquo top layers in composite have no significant destruction the MWCNTs&rsquo metal coatings are continuous and consist of Fe3O4 and Cr2O3. It is shown that the interface between the MWCNTs and pyrolytic Fe and Cr coatings has a multilayer structure: a layer in which carbon atoms along with epoxy &ndash C&ndash O&ndash bonds form bonds with oxygen and metal atoms from the coating layer is formed on the outer surface of the MWCNT, a monolayer of metal carbide above it and an oxide layer on top. The iron oxide and chromium oxide adhesion is provided by single, double and epoxy chemical binding formation between carbon atoms of the MWCNT top layer and the oxygen atoms of the coating, as well as the formation of bonds with metal atoms. |
| Databáze: | OpenAIRE |
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