%0 Journal Article %T One-step synthesis of highly pure and well-crystallized vertically aligned carbon nanotubes %+ Laboratoire Edifices Nanométriques (LEDNA) %A Charon, Emeline %A Pinault, Mathieu %A Mayne-L'Hermite, Martine %A Reynaud, Cécile %< avec comité de lecture %@ 0008-6223 %J Carbon %I Elsevier %V 173 %P 758-768 %8 2020-10-24 %D 2020 %R 10.1016/j.carbon.2020.10.056 %K vertically aligned carbon nanotubes %K one-step catalytic chemical vapour deposition %K iron content %K purity %K crystallinity %K oxidation resistance %Z Chemical Sciences/Material chemistryJournal articles %X The one-step aerosol-assisted catalytic chemical vapor deposition (CCVD) process, when operated in a H$_2$-based carrier gas, is shown to be effective at an extremely low ferrocene content (0.1wt.% in toluene), which enables to efficiently prepare forests of vertically aligned multiwalled carbon nanotubes (VACNTs) with high purity and good crystalline level. The resulting iron content in VACNT sample is only 0.5wt.% corresponding to a high catalytic yield of 200 while the steady growth rate (20 $\mu$m/min) is maintained at a significant value. The iron content in the sample is found proportional to the ferrocene concentration in the precursor, and when it decreases, a noticeable reduction in the iron encapsulation frequency in the nanotube channel is plainly observed. Lowering the ferrocene concentration generates a reduction in the VACNT number density while the growth rate increases and CNT diameters and crystalline structure remain similar. Such significant purity and crystalline levels involves a high oxidation resistance of the VACNT forest. These results, together with the in-situ continuous growth feature of the one-step aerosol assisted CCVD process, open up towards a new VACNT range made of pure and well-crystallized multi-walled carbon nanotubes, which is of interest for industrial production and commercial applications. %G English %2 https://cea.hal.science/cea-03002425/document %2 https://cea.hal.science/cea-03002425/file/Charon_Carbon2020_V0.pdf %L cea-03002425 %U https://cea.hal.science/cea-03002425 %~ CEA %~ CNRS %~ PUBNIMBE %~ DSV %~ INC-CNRS %~ IRAMIS-NIMBE %~ CEA-UPSAY %~ UNIV-PARIS-SACLAY %~ CEA-DRF %~ TEST-HALCNRS %~ UNIVERSITE-PARIS-SACLAY %~ GS-ENGINEERING %~ IRAMIS %~ GS-CHIMIE %~ GS-PHYSIQUE %~ INSTITUT-SCIENCES-LUMIERE %~ TEST2-HALCNRS