scholarly journals Impact of Mo and Ce on growth of single-walled carbon nanotubes by chemical vapour deposition using MgO-supported Fe catalysts

2009 ◽  
Vol 255 (16) ◽  
pp. 7446-7450 ◽  
Author(s):  
Abdel-Nasser A. El-Hendawy ◽  
Robert J. Andrews ◽  
Andrew J. Alexander
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Fe Catalysts ◽  
Walled Carbon Nanotubes

scholarly journals Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes

2018 ◽  
Vol 5 (8) ◽  
pp. 180345 ◽  
Author(s):  
Rong Xiang ◽  
Shigeo Maruyama
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Single Walled Carbon Nanotubes ◽  
Systematic Investigation ◽  
Metal Loss ◽  
Single Walled Carbon ◽  
Monometallic Catalysts ◽  
Walled Carbon Nanotubes

A catalyst is essential for the controlled synthesis of single-walled carbon nanotubes (SWNTs) by chemical vapour deposition (CVD). However, it is difficult to observe these nanosized particles in their original forms and in a statistical manner, which has resulted in a vague understanding of the behaviours of these particles. We present a technique to solve this long-standing issue. The key is to have an MEMS fabricated suspended SiO 2 layer, which is thick enough to support catalyst deposition and nanotube growth but thin enough to allow electron beams to transit. On a 20 nm SiO 2 film, we confirm that catalyst can be observed at an atomic resolution, and the catalyst–SWNT junctions can also be routinely observed. As a demonstration of this technique, we revisited the behaviour of monometallic catalysts through a systematic investigation of the size, chemical state and crystal structure of particles before and after high-temperature CVD. The active catalyst is found to follow a tangential growth mode, while the inactive catalyst is divided into three mechanisms: size growth, metal loss and inappropriate precipitation. The latter two mechanisms were not possible to observe by previous techniques.

scholarly journals Comparison of Straight and Helical Nanotube Production in a Swirled Fluid CVD Reactor

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Graham Bathgate ◽  
Sunny Iyuke ◽  
Frank Kavishe
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Continuous Production ◽  
Chemical Vapour ◽  
Single Walled Carbon Nanotubes ◽  
Helical Structure ◽  
Synthesis Process ◽  
Helical Tubes ◽  
Walled Carbon Nanotubes

Research into Carbon Nanotubes and their applications is fast becoming an extremely popular topic, and any means to greatly improve the synthesis process has a huge marketability. While investigating the feasibility of continuous production of single-walled carbon nanotubes in a vertical Swirled Fluid Chemical Vapour Deposition (CVD) reactor, it was discovered that helical nanotubes were lifted from the reactor by the gas current while straight tubes remained behind. Investigation into the merits provided by the helical structure illustrated the greatly increased likeliness for helical tubes to be lifted from the reactor by the carrier gas giving rise to positive speculation of their possible use in vertical CVD reactors in the future.

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