镧系元素的含量和类型对LnO覆盖的碳纳米片结构的影响：电子顺磁共振和X射线光电子能谱研究

Influence of Content and Type of Lanthanide on the Structure of LnO-Covered Carbon Nanoflakes: The EPR and XPS Study.

作者信息

Savilov Serguei V, Suslova Evgeniya V, Ulyanov Alexander N, Maslakov Konstantin I, Maximov Sergey V, Shashurin Denis A, Chelkov Georgy A

机构信息

Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia.

Faculty of Medicine, Medical Scientific-Educational Institute, Lomonosov Moscow State University, Moscow 119991, Russia.

出版信息

Nanomaterials (Basel). 2025 Jul 1;15(13):1016. doi: 10.3390/nano15131016.

DOI:10.3390/nano15131016

PMID:40648723

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12250894/

Abstract

Synthesized LnO (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 LnO in the LnO/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 LnO/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 ion solution, the number of unpaired electrons was reduced, presumably due to the formation of C-O-Ln bonds. All Ln ions changed the composites' EPR spectra by reducing the number of unpaired electrons in the CNF structure.

摘要

尺寸为1 - 3纳米、5 - 6纳米和10 - 15纳米的合成LnO（Ln = 镧、钕或钆）纳米颗粒通过碳纳米片（CNF）得以稳定。LnO/CNF复合材料中LnO的重量含量为20 - 50重量%，这使得这些复合材料有潜力作为计算机断层扫描和磁共振成像造影剂实际应用。通过X射线衍射数据、X射线光电子能谱（XPS）和电子顺磁共振（EPR）对CNF和LnO/CNF复合材料的结构进行了研究。原始CNF的EPR谱无信号。CNF表面的氧化导致在碳载体中出现与两种未成对电子相关的顺磁中心。在用Ln离子溶液浸渍CNF后，未成对电子的数量减少，推测是由于形成了C - O - Ln键。所有Ln离子都通过减少CNF结构中未成对电子的数量改变了复合材料的EPR谱。