3D Frameworks with Variable Magnetic and Electrical Features from Sintered Cobalt-Modified Carbon Nanotubes
3D frameworks of carbon nanotubes (CNTs) uniformly decorated by cobalt oxide or carbon-encapsulated cobalt nanoparticles were obtained by spark plasma sintering for the first time. The influence of the sintering temperature (T S) and Co content on the morphology, structure, and electrical and magnet...
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Published in | ACS applied materials & interfaces Vol. 10; no. 24; pp. 20983 - 20994 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
20.06.2018
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Subjects | |
Online Access | Get full text |
ISSN | 1944-8244 1944-8252 1944-8252 |
DOI | 10.1021/acsami.8b04367 |
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Summary: | 3D frameworks of carbon nanotubes (CNTs) uniformly decorated by cobalt oxide or carbon-encapsulated cobalt nanoparticles were obtained by spark plasma sintering for the first time. The influence of the sintering temperature (T S) and Co content on the morphology, structure, and electrical and magnetic properties of the obtained materials was investigated by Raman spectroscopy, electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and in situ magnetometry. It was shown that application of the SPS technique allowed simultaneous compaction of the material, formation of CNT framework, and Co oxide reduction. The appearance of the carbon shell around 4–10 nm Co particles was observed at T S > 600 °C. At higher T S, the Co particle size increased (up to 300 nm at 1400 °C), whereas the carbon shell ordered and thickened. The formation of large-size few-layers graphene sheets was observed at T S = 1400 °C. Electrical conductivity of the composites was found to be higher than that of sintered pristine CNTs and varied in the range of 500–12 500 Sm/m. Magnetic experiments demonstrated soft magnetization of the samples and the coercivity of 200–300 Oe. Thus, the obtained CNT-based material is simultaneously compact, formable, electroconductive, and ferromagnetic. Its properties can be tuned by variation of the sintering parameters. Synthesized cobalt-modified carbon 3D structures are promising for the application in magnetic separation, catalysis, fuel cells, and electromagnetic shielding. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1944-8244 1944-8252 1944-8252 |
DOI: | 10.1021/acsami.8b04367 |