Electron paramagnetic resonance investigation of purified catalyst-free single-walled carbon nanotubes
| Autor: | Arzhang Ardavan, John J. L. Morton, G. A. D. Briggs, Mujtaba Zaka, Alex W. Robertson, Jamie H. Warner, Wenjing Yan, Yimin A. Wu, Huiliang Wang, Staunton D, Mark H. Rümmeli, Yasuhiro Ito, Hashimoto T |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
inorganic chemicals
Materials science Time Factors Iron Analytical chemistry General Physics and Astronomy chemistry.chemical_element Carbon nanotube Spectrum Analysis Raman Vibration Catalysis law.invention Absorption Magnetics law General Materials Science Graphite Electron paramagnetic resonance Laser ablation Nanotubes Carbon General Engineering Electron Spin Resonance Spectroscopy Temperature Amorphous carbon chemistry Particle Volatilization Carbon Ultracentrifugation |
| Zdroj: | ACS nano. 4(12) |
| ISSN: | 1936-086X 1936-0851 |
| Popis: | Electron paramagnetic resonance of single-walled carbon nanotubes (SWCNTs) has been bedevilled by the presence of paramagnetic impurities. To address this, SWCNTs produced by laser ablation with a nonmagnetic PtRhRe catalyst were purified through a multiple step centrifugation process in order to remove amorphous carbon and catalyst impurities. Centrifugation of a SWCNT solution resulted in sedimentation of carbon nanotube bundles containing clusters of catalyst particles, while isolated nanotubes with reduced catalyst particle content remained in the supernatant. Further ultracentrifugation resulted in highly purified SWCNT samples with a narrow diameter distribution and almost no detectable catalyst particles. Electron paramagnetic resonance (EPR) signals were detected only for samples which contained catalyst particles, with the ultracentrifuged SWCNTs showing no EPR signal at X-band (9.4 GHz) and fields < 0.4 T. © 2010 American Chemical Society. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|