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Reversed micelles containing metallic ions are used as precursors of novel catalysts for the gas-phase synthesis of single-walled carbon nanotubes (SWNTs) and the results of screening study on catalytic behavior of Fe-Mo binary catalysts are reported. The results suggested that the catalytic ability is closely related to the strain of the crystal structure of Fe-Mo catalysts formed in the reaction and/or the phase transition caused by dissolution of the Mo atoms.

A statistical and macroscopic analysis to estimate the catalyst activity of water-assisted growth of single-walled nanotubes (SWNT) and to characterize SWNT forests is proposed. The catalyst activity is estimated to be 84% (plusmn 6%), the highest ever reported.

Size-controlled Co, Co-Mo, and Fe-Mo nanoparticles is prepared by the reversed micelle method as the catalysts for the gas-phase pyrolytic synthesis of single-walled carbon nanotubes (SWCNTs). Findings reveal that the alkyl groups of the surfactants play a role in controlling the sizes of the nanoparticles.

The compatibility of various catalysts for ethylene and ethanol chemical vapor deposition (CVD) syntheses of single-walled carbon nanotubes (SWNTs) on Si substrates is studied. A strong selectivity between the catalyst elemental species and carbon source is found and SWNT yield for Fe(Co) catalysts is much higher for ethylene (ethanol) CVD than for ethanol (ethylene) CVD.

Single-walled carbon nanotubes (SWNTs) with a narrow diameter distribution are synthesized by thermal chemical vapor deposition (CVD) of methane over Fe/MgO catalyst on the basis of parametric study considering Fe loading, reaction temperature and time, methane concentration, and structure of a support material. We found that the porous MgO support gives the SWNTs with a narrow diameter distribution with the mean diameter and standard deviation of 0.93 and 0.06 nm, respectively, only when the Fe loading and reaction temperature are relatively low. The higher Fe loading and/or the higher reaction temperature enlarged the nanotube diameter, forming double-walled carbon nanotubes (DWNTs) in addition to SWNTs. This result indicates that only the diameter of Fe nanoparticles determines the growth of either SWNTs or DWNTs on the MgO support. The fluorescence and absorption spectra of the nanotube dispersion in D(2)O solution with sodium dodecyl sulfate (SDS) were studied to identify their chirality distribution. The fluorescence of the uniform-diameter SWNTs indicates the formation of the near armchair structures. On the other hand, the SWNTs synthesized over the catalyst with a high Fe loading, 3 wt %, showed a wide chirality distribution including the near zigzag structure. The synthesis of the SWNTs with a narrow diameter distribution could be applied to the selection of SWNTs with a specific chirality based on postsynthesis separation.