TEM investigation on the growth mechanism of carbon nanotubes synthesized by hot-filament chemical vapor deposition

Synthesis of nickel nanocapsules and carbon nanotubes via methane CVD

“…We can assume that the concentration of rings other than six was slightly higher at the lower process temperature. As was mentioned above, different morphologies of carbon nanostructures can be obtained at different CVD temperature: MWCNT at 600 • C, CNC at 650 • C and 750 • C. Although the real mechanism of CNT and CNC growth has not been fully understood yet, the adsorption of carbon precursor-decomposition of carbon precursor-carbon diffusion-nucleation process, is the generally accepted scheme [31][32][33][34]. CH 4 molecules are adsorbed on the upper surface of Ni particles and decomposed into C and H atoms.…”

“…There are two possible diffusion pathways, i.e., bulk diffusion and surface diffusion. It is generally agreed [32,34] that the diffusion of carbon through the catalyst particle is the rate-determining step in the growth of carbon nanostructures.…”

TEM studies of the initial stage growth and morphologies of bamboo-shaped carbon nanotubes synthesized by CVD

“…Because a thorough understanding of the formation mechanisms for such carbon nanostructures is crucial to design procedures for controlling the growth conditions in order to obtain structures which might be directly used in different fields in nanotechnology. Recently, though some models describing the formation of bamboo-shaped CNTs fabricated by CVD have been suggested in the literature [10][11][12]. However, the growth mechanism of bamboo-shaped CNTs by the CVD method is still under discussion.…”

One-Dimensional Carbon Nanostructures—From Synthesis to Nano-electromechanical Systems Sensing Applications—

“…The CVD technique is the most reported in the literature owing to advantages such as lower processing temperature, possibility of controlling the CNT structure, high purity as well as large-quantity production. (26,27) In the electric arc discharge method, a high-current electric arc goes through graphite electrodes in the presence of catalytic particles forming CNTs and soot. (15,28) This process is performed in a chamber filled with argon or helium gas.…”