Multiwall Carbon Nanotubes by Hydrothermal Treatment

2000 ◽  
Vol 633 ◽  
Author(s):  
Jose M. Calderon-Moreno ◽  
Masahiro Yoshimura

AbstractMultiwall carbon nanotubes have been obtained from carbon soot after hydrothermal treatment at 800°C and 100 MPa. High-resolution electron microscopy (HRTEM) study reveals multiwall carbon nanotubes and carbon nanoparticles made of a hollow core enclosed in well-ordered concentric graphitic layers after hydrothermal treatment. Condensed solid products are free of the amorphous phase. Micro-Raman spectroscopy reveals that the hydrothermal multiwall nanotubes have a characteristic perfectly closed graphitic lattice in the basal plane, without edges or plane terminations.

2013 ◽  
Vol 19 (5) ◽  
pp. 1298-1302 ◽  
Author(s):  
Filippo S. Boi ◽  
Gavin Mountjoy ◽  
Zofia Luklinska ◽  
Liam Spillane ◽  
Lisa S. Karlsson ◽  
...  

AbstractStructures comprising single-crystal, iron-carbon-based nanowires encapsulated by multiwall carbon nanotubes self-organize on inert substrates exposed to the products of ferrocene pyrolysis at high temperature. The most commonly observed encapsulated phases are Fe3C, α-Fe, and γ-Fe. The observation of anomalously long-period lattice spacings in these nanowires has caused confusion since reflections from lattice spacings of ≥0.4 nm are kinematically forbidden for Fe3C, most of the rarely observed, less stable carbides, α-Fe, and γ-Fe. Through high-resolution electron microscopy, selective area electron diffraction, and electron energy loss spectroscopy we demonstrate that the observed long-period lattice spacings of 0.49, 0.66, and 0.44 nm correspond to reflections from the (100), (010), and (001) planes of orthorhombic Fe3C (space group Pnma). Observation of these forbidden reflections results from dynamic scattering of the incident beam as first observed in bulk Fe3C crystals. With small amounts of beam tilt these reflections can have significant intensities for crystals containing glide planes such as Fe3C with space groups Pnma or Pbmn.


2018 ◽  
Author(s):  
Gen Hayase

By exploiting the dispersibility and rigidity of boehmite nanofibers (BNFs) with a high aspect ratio of 4 nm in diameter and several micrometers in length, multiwall-carbon nanotubes (MWCNTs) were successfully dispersed in aqueous solutions. In these sols, the MWCNTs were dispersed at a ratio of about 5–8% relative to BNFs. Self-standing BNF–nanotube films were also obtained by filtering these dispersions and showing their functionality. These films can be expected to be applied to sensing materials.


2016 ◽  
Vol 25 (4) ◽  
pp. 459-464 ◽  
Author(s):  
M.I. Abduo ◽  
A.S. Dahab ◽  
Hesham Abuseda ◽  
Abdulaziz M. AbdulAziz ◽  
M.S. Elhossieny

2021 ◽  
Vol 4 (3) ◽  
pp. 2345-2350
Author(s):  
Chaofeng Wang ◽  
Yi Hao ◽  
Yue Wang ◽  
Huijia Song ◽  
Sameer Hussain ◽  
...  

2015 ◽  
Vol 1782 ◽  
pp. 1-8
Author(s):  
Ning-Qin Deng ◽  
He Tian ◽  
Qing-Tang Xue ◽  
Zhe Wang ◽  
Hai-Ming Zhao ◽  
...  

ABSTRACTNanogenerators (NGs) have great potential to solve the problems of energy depletion and environmental pollution. Here, two types of flexible nanogenerators (FNGs) based on graphene oxide (GO) and multiwall carbon nanotubes (MW-CNTs) are presented. The peak output voltage and current of GO based FNG reached up to 2 V and 30 nA, respectively, under 15 N force at 1 Hz. Moreover, the output voltage could be improved to 34.4 V when the frequency was increased to 10 Hz. It was also found the output voltage increased from 0.1 V to 2.0 V using a released GO structure. The other FNG was made by MW-CNTs mixed with ZnO nanoparticles (NPs). Its output voltage and power reached up to 7.5 V and 18.75 mW, respectively, which is much larger than that of bare ZnO based FNG. Furthermore, a peak voltage of 30 V could be gained by stamping one’s foot on the FNG. Finally, a modified NG was fabricated using four springs and two flexible layers. As a result, the voltage and power reached up to 9 V and 27mW, respectively. These works may bring out broad applications in energy harvesting.


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