Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study

Synthesized Ln<sub>2</sub>O<sub>3</sub> (Ln = La, Nd or Gd) nanoparticles with sizes of 1–3 nm, 5–6 nm and 10–15 nm were stabilized by carbon nanoflakes (CNFs). The weight content of Ln<sub>2</sub>O<sub>3</sub> in the Ln<sub>2</sub>O<sub...

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Main Authors: Serguei V. Savilov, Evgeniya V. Suslova, Alexander N. Ulyanov, Konstantin I. Maslakov, Sergey V. Maximov, Denis A. Shashurin, Georgy A. Chelkov
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/15/13/1016
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author Serguei V. Savilov
Evgeniya V. Suslova
Alexander N. Ulyanov
Konstantin I. Maslakov
Sergey V. Maximov
Denis A. Shashurin
Georgy A. Chelkov
author_facet Serguei V. Savilov
Evgeniya V. Suslova
Alexander N. Ulyanov
Konstantin I. Maslakov
Sergey V. Maximov
Denis A. Shashurin
Georgy A. Chelkov
author_sort Serguei V. Savilov
collection DOAJ
description Synthesized Ln<sub>2</sub>O<sub>3</sub> (Ln = La, Nd or Gd) nanoparticles with sizes of 1–3 nm, 5–6 nm and 10–15 nm were stabilized by carbon nanoflakes (CNFs). The weight content of Ln<sub>2</sub>O<sub>3</sub> in the Ln<sub>2</sub>O<sub>3</sub>/CNF composites was 20–50 wt. %, which makes these composites potentially suitable for practical use as computed tomography and magnetic resonance imaging contrast agents. The structure of CNFs and Ln<sub>2</sub>O<sub>3</sub>/CNF composites was investigated by X-ray diffraction data, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The EPR spectra of raw CNFs were silent. The oxidation of the CNF surface resulted in the appearance of paramagnetic centers associated with two types of unpaired electrons in the carbon support. After impregnation of the CNFs with the Ln<sup>3+</sup> ion solution, the number of unpaired electrons was reduced, presumably due to the formation of C–O–Ln bonds. All Ln<sup>3+</sup> ions changed the composites’ EPR spectra by reducing the number of unpaired electrons in the CNF structure.
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spelling doaj-art-fb52cccd67de401e82cfacb178c444e52025-08-20T03:17:08ZengMDPI AGNanomaterials2079-49912025-07-011513101610.3390/nano15131016Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS StudySerguei V. Savilov0Evgeniya V. Suslova1Alexander N. Ulyanov2Konstantin I. Maslakov3Sergey V. Maximov4Denis A. Shashurin5Georgy A. Chelkov6Chemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaChemistry Department, Lomonosov Moscow State University, Moscow 119991, RussiaSynthesized Ln<sub>2</sub>O<sub>3</sub> (Ln = La, Nd or Gd) nanoparticles with sizes of 1–3 nm, 5–6 nm and 10–15 nm were stabilized by carbon nanoflakes (CNFs). The weight content of Ln<sub>2</sub>O<sub>3</sub> in the Ln<sub>2</sub>O<sub>3</sub>/CNF composites was 20–50 wt. %, which makes these composites potentially suitable for practical use as computed tomography and magnetic resonance imaging contrast agents. The structure of CNFs and Ln<sub>2</sub>O<sub>3</sub>/CNF composites was investigated by X-ray diffraction data, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The EPR spectra of raw CNFs were silent. The oxidation of the CNF surface resulted in the appearance of paramagnetic centers associated with two types of unpaired electrons in the carbon support. After impregnation of the CNFs with the Ln<sup>3+</sup> ion solution, the number of unpaired electrons was reduced, presumably due to the formation of C–O–Ln bonds. All Ln<sup>3+</sup> ions changed the composites’ EPR spectra by reducing the number of unpaired electrons in the CNF structure.https://www.mdpi.com/2079-4991/15/13/1016lanthanidesgadoliniumcarbon nanoflakeselectronic structureelectron paramagnetic resonanceX-ray photoelectron spectroscopy
spellingShingle Serguei V. Savilov
Evgeniya V. Suslova
Alexander N. Ulyanov
Konstantin I. Maslakov
Sergey V. Maximov
Denis A. Shashurin
Georgy A. Chelkov
Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
Nanomaterials
lanthanides
gadolinium
carbon nanoflakes
electronic structure
electron paramagnetic resonance
X-ray photoelectron spectroscopy
title Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
title_full Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
title_fullStr Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
title_full_unstemmed Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
title_short Influence of Content and Type of Lanthanide on the Structure of Ln<sub>2</sub>O<sub>3</sub>-Covered Carbon Nanoflakes: The EPR and XPS Study
title_sort influence of content and type of lanthanide on the structure of ln sub 2 sub o sub 3 sub covered carbon nanoflakes the epr and xps study
topic lanthanides
gadolinium
carbon nanoflakes
electronic structure
electron paramagnetic resonance
X-ray photoelectron spectroscopy
url https://www.mdpi.com/2079-4991/15/13/1016
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