Synthesis and growth mechanism of carbon nanotubes and nanofibers from ethanol flames

Flame-synthesis limits and self-catalytic behavior of carbon nanotubes using a double-faced wall stagnation flow burner

“…Various mechanisms for the growth of carbon nano materials, including CNTs and carbon nanofibers (CNFs), have been suggested [2][3][4][5][6][7][8]11,[16][17][18][19]. Rao et al [16] reviewed the growth mechanisms of CNTs, discussing the effect of catalyst particle size on the growth mechanism and structure of CNTs.…”

“…In the case of the adsorption rate of carbon atoms at the catalyst particle-gas interface smaller than the critical value, the tip-type growth mode is established. In addition to the 'base-type' and 'tip-type' mechanisms, the 'hollow-cored' and 'solid-cored' mechanisms were proposed [8]. In the case of the 'hollow-cored' mechanism, when the pyrolyzed carbon atoms deposit upon the catalyst particles that have a weak affinity for carbon, carbon atoms generally move faster along the external surface than the interior, and the hollowcored CNTs are formed.…”

“…Recently there has been increasing interest in mass production of CNTs by catalytic combustion [2][3][4][5][6][7][8]. Most investigations have been focused on the fundamental aspects of combustion synthesis of CNTs for various flame configurations.…”

Synthesizing carbon nanotubes and carbon nanofibers over supported-nickel oxide catalysts via catalytic decomposition of methane

“…According to Vander Wal et al [12], carbon nanotubes are referred to as a highly graphitic structure with the orientation of the basal carbon planes parallel to the tube axis and carbon nanofibers are the structures with the other orientations of the graphitic lamella that will leave a smaller or no central channel. According to Pan et al [13] and Pérez-Cabero et al [14], the term "carbon nanotubes" is used to refer to the filamentous carbons with a center channel or hollow core and filamentous carbons without a central channel is denoted as "carbon nanofibers", regardless of the graphitic structure. In this paper, we adopted the definitions for the filamentous carbons given by the latter as they are easily comprehended in explaining the types of filamentous carbons synthesized in this work.…”

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.…”