Synthesis of high-quality single-walled carbon nanotubes by catalytic decomposition of C2H2

Abstract

High-quality single-walled carbon nanotubes free of defects and amorphous carbon coating have been produced by catalytic decomposition of C2H2 over Fe-Mo/Al2O3 catalyst.

A temperature window for the synthesis of single-walled carbon nanotubes by catalytic chemical vapor deposition of CH4 over Mo-Fe/MgO catalyst

“…According to the equation x RBM = 6.5 ? 223.75/d t (cm -1 ) [14], the diameter of SWCNTs synthesized at 800°C varies from 0.86 to 1.73 nm, which accords with the result of the TEM image (Fig. 3a).…”

A Temperature Window for the Synthesis of Single-Walled Carbon Nanotubes by Catalytic Chemical Vapor Deposition of CH4over Mo2-Fe10/MgO Catalyst

“…3 a), we can observe that there are a few single SWCNT and SWCNTs bundle with different diameters. According to the equation ω RBM = 6.5 + 223.75/ d t (cm −1 ) [ 14 ], the diameter of SWCNTs synthesized at 800 °C varies from 0.86 to 1.73 nm, which accords with the result of the TEM image (Fig. 3 a).…”

“…In the lower wavenumber region (100–300 cm −1 ), two outstanding RBM bands are presented. According to the formula [ 14 ], the peaks at 147 and 169 cm −1 correspond to the SWCNTs with diameter of 1.59 and 1.38 nm, respectively. The TEM image (Fig.…”

Morphological Evolution of Fe–Mo Bimetallic Catalysts for Diameter and Density Modulation of Vertically Aligned Carbon Nanotubes

“…Besides the monometallic catalysts of transition metals (i.e., Fe, Ni, and Co), multicomponent catalysts have been regarded useful for CVD synthesis of VA-CNTs. A number of studies in the past decades have reported about the potential of such binary and ternary catalysts toward chirality selection, , size control, quality enhancement, − and low-temperature growths. − Mo added to an Fe-catalyzed CVD process has been drawing attention due to its promise of higher growth efficiency, particularly when the Mo-to-Fe ratio is tuned very low. ,,− It is presumed that pure Mo does not participate in the CNT nucleation for it converts to Mo carbide (Mo 2 C) during the CVD process. Earlier studies, nevertheless, discovered that when used as a cocatalyst, Mo can alter the catalyst-assisted reactions of feedstock gases by forming alloy catalysts. , Later, an in situ environmental transmission electron microscopy (TEM) study has revealed that Fe–Mo catalysts can evolve into not only inactive Mo-rich Fe–Mo oxide (Fe 2 Mo 3 O 8 ) but also into active forms such as FeMo carbide ((Fe,Mo) 23 C 6 ) and Fe carbide (Fe 3 C) depending on the Mo content. , …”