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Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers

We report results of comprehensive experimental exploration (X-ray photoemission, Raman and optical spectroscopy) of carbon nanofibers (CNFs) in combination with first-principles modeling. Core-level spectra demonstrate prevalence of sp2 hybridization of carbon atoms in CNF with a trace amount of ca...

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Autores principales: Boukhvalov, D. W., Zhidkov, I. S., Kiryakov, A., Menéndez, J. L., Fernández-García, L., Kukharenko, A. I., Cholakh, S. O., Zatsepin, A. F., Kurmaev, E. Z.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer US 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8505591/
https://www.ncbi.nlm.nih.gov/pubmed/34633574
http://dx.doi.org/10.1186/s11671-021-03595-y
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author Boukhvalov, D. W.
Zhidkov, I. S.
Kiryakov, A.
Menéndez, J. L.
Fernández-García, L.
Kukharenko, A. I.
Cholakh, S. O.
Zatsepin, A. F.
Kurmaev, E. Z.
author_facet Boukhvalov, D. W.
Zhidkov, I. S.
Kiryakov, A.
Menéndez, J. L.
Fernández-García, L.
Kukharenko, A. I.
Cholakh, S. O.
Zatsepin, A. F.
Kurmaev, E. Z.
author_sort Boukhvalov, D. W.
collection PubMed
description We report results of comprehensive experimental exploration (X-ray photoemission, Raman and optical spectroscopy) of carbon nanofibers (CNFs) in combination with first-principles modeling. Core-level spectra demonstrate prevalence of sp2 hybridization of carbon atoms in CNF with a trace amount of carbon–oxygen bonds. The density functional theory (DFT)-based calculations demonstrated no visible difference between mono- and bilayers because σ-orbitals are related to in-plane covalent bonds. The influence of the distortions on π-peak is found to be significant only for bilayers as a result of π–π interlayer bonds formation. These results are supported by both experimental Raman and XPS valence band spectra. The combination of optical measurements with a theoretical modeling indicates the formation of optically active graphene quantum dots (GQDs) in the CNF matrix, with a radiative relaxation of the excited π* state. The calculated electronic structure of these GQDs is in quantitative agreement with the measured optical transitions and provides an explanation of the absence of visible contribution from these GQDs to the measured valence bands spectra.
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spelling pubmed-85055912021-10-27 Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers Boukhvalov, D. W. Zhidkov, I. S. Kiryakov, A. Menéndez, J. L. Fernández-García, L. Kukharenko, A. I. Cholakh, S. O. Zatsepin, A. F. Kurmaev, E. Z. Nanoscale Res Lett Nano Express We report results of comprehensive experimental exploration (X-ray photoemission, Raman and optical spectroscopy) of carbon nanofibers (CNFs) in combination with first-principles modeling. Core-level spectra demonstrate prevalence of sp2 hybridization of carbon atoms in CNF with a trace amount of carbon–oxygen bonds. The density functional theory (DFT)-based calculations demonstrated no visible difference between mono- and bilayers because σ-orbitals are related to in-plane covalent bonds. The influence of the distortions on π-peak is found to be significant only for bilayers as a result of π–π interlayer bonds formation. These results are supported by both experimental Raman and XPS valence band spectra. The combination of optical measurements with a theoretical modeling indicates the formation of optically active graphene quantum dots (GQDs) in the CNF matrix, with a radiative relaxation of the excited π* state. The calculated electronic structure of these GQDs is in quantitative agreement with the measured optical transitions and provides an explanation of the absence of visible contribution from these GQDs to the measured valence bands spectra. Springer US 2021-10-11 /pmc/articles/PMC8505591/ /pubmed/34633574 http://dx.doi.org/10.1186/s11671-021-03595-y Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Nano Express
Boukhvalov, D. W.
Zhidkov, I. S.
Kiryakov, A.
Menéndez, J. L.
Fernández-García, L.
Kukharenko, A. I.
Cholakh, S. O.
Zatsepin, A. F.
Kurmaev, E. Z.
Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title_full Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title_fullStr Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title_full_unstemmed Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title_short Unveiling the Atomic and Electronic Structure of Stacked-Cup Carbon Nanofibers
title_sort unveiling the atomic and electronic structure of stacked-cup carbon nanofibers
topic Nano Express
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8505591/
https://www.ncbi.nlm.nih.gov/pubmed/34633574
http://dx.doi.org/10.1186/s11671-021-03595-y
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