Influence of Nitrogen on the Growth Mechanism of Decorated C:N Nanotubes

Abstract

Nanotubes like feather boas were synthesised by the decomposition of methane in a nitrogen atmosphere using a bias‐enhanced hot‐filament chemical vapour deposition technique. This new type of slightly nitrogenated carbon (C:N) nanotubes exhibits a vermicular shape. Graphitic thin foils growing perpendicular to the tube axis typically cover the surface of each C:N tube. High‐resolution transmission electron microscopy reveals the graphitic structure to be characterised by strong disorder at different length scales. The role of small amounts of nitrogen, which affects the structural formation of the growing C:N tubes, is discussed.

Generation of radical species in CVD grown pristine and N-doped solid carbon spheres using H2 and Ar as carrier gases

“…The rst decomposition peak can again be attributed to the loss of amorphous carbon domains 61 resulting from sp 3 hybridized carbons and to nitrogen induced defects within the carbon lattice. [62][63][64] The second decomposition peak centered at 635 C was higher than that observed in the N-doped CSs produced in the presence of H 2 (593 C); indicating a higher thermal stability and the presence of fewer edge defects, consistent with the Raman and XPS data (see below).…”

“…This could be associated with the loss of amorphous carbon domains 61 resulting from sp 3 hybridized carbons and to nitrogen bonded to sp 3 hybridized carbon formed from the new carbon layer. The decomposition peaks at higher temperatures (>520 C) in the N-doped carbon spheres can be attributed to the structural disorder and defects brought about by the presence of N in the carbon lattice [62][63][64] as conrmed by the high I D /I G ratio from the Raman data. Fig.…”

“…The high percentage of pyridinic-N and pyrrolic-N can be ascribed to the hydrogen induced edge defects. 63,64 In contrast, the NCSs-Ar had 18% pyridinic-N, 20% pyrrolic-N and 50% graphitic-N and 12% NO X , respectively (Table 4). The high percentage of graphitic-N can be ascribed to the rearrangement of the carbon and nitrogen atoms within the carbon lattice during the postdoping process in the CSs obtained in the presence of Ar.…”

Heteroatom‐containing ferrocene derivatives as catalysts for MWCNTs and other shaped carbon nanomaterials

“…This may be due to distortion of the growing tube by the incorporation of nitrogen. This supposition is supported by the research of Kurt and Karimi …”

Insights into carbon nanotube growth using an automated gravimetric apparatus

“…The undesirable bamboo morphology is generally attributed to nitrogen incorporation, leading to pentagon-induced curvature and cap formation [111][112][113][114][115], with a prevalence related to temperature and carbon supply [116]. However, bamboo morphology (and others) is also favoured at certain conditions in the absence of nitrogen [109].…”