Parametric Study on Growth of Carbon Nanocoil by Catalytic Chemical Vapor Deposition

Abstract

Carbon nanocoils (CNCs) were synthesized by the catalytic pyrolysis of acetylene over a mixture of Fe and SnO2 particles in a chemical vapor deposition (CVD) apparatus. The effects of reaction temperature, the composition of Fe and SnO2 in the catalyst, and the ratio of acetylene (C2H2) to helium (He) gas were examined. An optimum output was obtained when the Fe/SnO2 ratio was 2/1, the flow rates of C2H2 and He gases were 150 and 700 sccm, respectively, and the reaction temperature was 700°C. Under these conditions, the CNCs were of 80% purity, with average coil diameters of 750 nm, fiber diameters of 300 nm and pitches of approximately 750 nm. The CNC yield weighed up to 60 times that of the catalyst in 10 min.

Syntheses and Electronic Applications of Helical Carbon Nanofibers

“…As stated in Section 2, Baker found the effect of binary-catalyst on HCNF growth, and then various combinations of binary-catalysts for HCNF growth have been found, e.g. Fe/ITO (Zhang et al, 2000), Fe/SnO 2 , (Xu et al, 2005), Fe/Sn (Hokshin et al, 2007), Fe-based Fig. 2.…”

“…Pyrolysis of C 2 H 2 was carried out on 10 mg mixture of Fe and SnO 2 at 700ºC for 10 min with the flow rates of C 2 H 2 and He gases of 180 and 420 ml/min, respectively. (Xu et al, 2005) Figure 4 shows SEM micrographs of carbon materials deposited on catalysts of various compositions. On the catalyst with 20% Fe, as shown in (a), no significant carbon deposition can be observed.…”

High-Yield Synthesis of Helical Carbon Nanofibers Using Iron Oxide Fine Powder as a Catalyst

“…We have synthesized large quantities of CNCs by employing a drop-coating method that drops an Sn liquid solution mixed with Fe powder on a graphite substrate [43,44]. Using this method, the CNC purity on the surface of the deposits reached almost 100%.…”

Preparation of Powdery Carbon Nanotwist and Application to Printed Field Emitter

“…The CNR has a shape with multistrings twisted together. The HCNF has been synthesized and studied since the 1970s [4][5][6][7][8][9][10][11][12][13][14][15]. The CNC and CNTw relatively have good reproducibility, but CNR has been seldom seen.…”

“…So far, various catalysts have been tried. For example, for CNC, Ni [4], Fe-ITO [8], Cu-(Ni, Cr, Ti or Zn) [9], Au [10], Fe-SnO 2 [11,12], and Febased alloys (Fe-Cr-Mn-Mo, Fe-Cr-Ni-Mo (SUS513)) [13] have been tried, while for CNTw, Ni [4], Ni-Cu [3], Cu [14], and Fe-based alloys (Fe-Ni-Cr-Mo-Mn-Sn) [15] have been used. Compared with CNC, the CNTw has been able to be prepared in almost 100% purity with high uniformity of fiber diameter and shape [3].…”