Simple Metal-catalyst-free Production of Carbon Nanostructures

2013 ◽  
Vol 66 (11) ◽  
pp. 1435 ◽  
Author(s):  
Thomas K. Ellis ◽  
Christian Paras ◽  
Matthew R. Hill ◽  
John A. Stride

We report the metal-catalyst-free production of multiwalled carbon nanotubes and nanobubbles, in a chemical reduction of hexachlorobenzene by metallic sodium, giving high yields (in excess of 80 %) and at temperatures as low as 190°C for multiwalled carbon nanotubes and 100°C for nanobubble formation. The carbon nanotube samples produced under solvothermal conditions were found to consist of large bundles of nanotubes (>50 µm) consistent with a facial growth from the surface of the molten metal. Meanwhile, the nanobubbles produced under ambient pressure were found to be small (≤1 µm), polydispersed (smallest ~50 nm), and the bulk to have a large microporous area. With the regulatory complexities and high environmental and economic costs of remediating waste containing highly hazardous halogenated aromatic chemicals, necessitating high-temperature incineration under strictly controlled conditions, this low-temperature, low-cost chemical degradation of hexachlorobenzene is of great potential as a scalable and workable remediation technology.

Langmuir ◽  
2007 ◽  
Vol 23 (18) ◽  
pp. 9501-9504 ◽  
Author(s):  
Craig P. Jones ◽  
Kerstin Jurkschat ◽  
Alison Crossley ◽  
Richard G. Compton ◽  
Bill Logan Riehl ◽  
...  

2019 ◽  
Vol 48 (29) ◽  
pp. 11018-11033 ◽  
Author(s):  
Gabriela Mera ◽  
Peter Kroll ◽  
Ilia Ponomarev ◽  
Jiewei Chen ◽  
Koji Morita ◽  
...  

Bamboo-like MWCNTs in a mesoporous silica matrix are synthesized by a simple metal-catalyst-free single-source precursor approach.


2012 ◽  
Vol 3 ◽  
pp. 360-367 ◽  
Author(s):  
Luca Camilli ◽  
Manuela Scarselli ◽  
Silvano Del Gobbo ◽  
Paola Castrucci ◽  
Eric Gautron ◽  
...  

We have taken advantage of the native surface roughness and the iron content of AISI-316 stainless steel to grow multiwalled carbon nanotubes (MWCNTs) by chemical vapour deposition without the addition of an external catalyst. The structural and electronic properties of the synthesized carbon nanostructures have been investigated by a range of electron microscopy and spectroscopy techniques. The results show the good quality and the high graphitization degree of the synthesized MWCNTs. Through energy-loss spectroscopy we found that the electronic properties of these nanostructures are markedly different from those of highly oriented pyrolytic graphite (HOPG). Notably, a broadening of the π-plasmon peak in the case of MWCNTs is evident. In addition, a photocurrent was measured when MWCNTs were airbrushed onto a silicon substrate. External quantum efficiency (EQE) and photocurrent values were reported both in planar and in top-down geometry of the device. Marked differences in the line shapes and intensities were found for the two configurations, suggesting that two different mechanisms of photocurrent generation and charge collection are in operation. From this comparison, we are able to conclude that the silicon substrate plays an important role in the production of electron–hole pairs.


2010 ◽  
Vol 636-637 ◽  
pp. 703-708 ◽  
Author(s):  
E. Borowiak-Palen ◽  
A. Steplewska ◽  
A. Bachmatiuk ◽  
M.H. Rümmeli ◽  
R.K. Kalenczuk

In this contribution we present high resolution transmission electron microscopy (HR-TEM) and Raman studies on the synthesis of carbon nanotubes using platinum supported on MgO in alcohol - chemical vapour deposition (A-CVD). For comparison copper and iron catalysts mixed with the same metal loading in MgO and the same process parameters in A-CVD have been tested. Our findings show that the choice of catalyst utilized under the same experimental conditions strongly influences the final morphology of the carbon nanostructures. Application of Pt/MgO in CVD results in doublewalled carbon nanotubes (DWCNT) and multiwalled carbon nanotubes (MWCNT). Cu/MgO mixtures lead to the synthesis of copper filled multiwalled carbon nanotubes (Cu-MWCNT) and iron capsules surrounded by multiwalled carbon shells (Fe-MWCS), respectively. Our findings indicate that the three discussed metals interact differently with the substrate leading to the formation of different sized catalyst particles. The analysis of the particles size in the catalyst precursors and in the final products is also described in this contribution.


2012 ◽  
Vol 3 (6) ◽  
pp. 2083 ◽  
Author(s):  
Jian Li ◽  
Siew Qi Yap ◽  
Chee Fei Chin ◽  
Quan Tian ◽  
Sia Lee Yoong ◽  
...  

2019 ◽  
Vol 6 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Longze Zhao ◽  
Yong Cheng ◽  
Qiaobao Zhang ◽  
Ming-Sheng Wang

Two multiwalled carbon nanotubes are seamlessly joined via the crystallization of an amorphous carbon joint using a transmission electron microscope.


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