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Substrates pretreatment in suspensions of a detonation nanodiamond is widely used for nucleation of diamond growth by chemical vapor deposition (CVD). We found that iron inclusions in the nanodiamond provide catalytical growth of carbon nanotubes during CVD in a hot filament reactor (HF CVD). Carbon nanotubes grow in the area between two adjacent Si wafers. The diameters of such obtained nanotubes were in the range of 10–100 nm and the length of the tubes reaches about 10 µm. The proposed HF CVD method has convincing potential for the fabrication of carbon nanotube coatings on a large surface area. [ABSTRACT FROM AUTHOR]

The formation of active component of Fe–Mo and Co–Mo catalysts for carbon nanotube growth with variable Mo content is studied with in situ XRD, XPS, and STEM&EDX. The activation of bimetallic Fe–Mo catalysts under the growth conditions leads to the formation of Fe–Mo alloy particles in contrast to Co‐containing catalysts in which active alloy incorporates only a small portion of Mo (<2–3 at.%). The stable carbide formation for these systems is not detected. The effect of Mo content in Fe–Mo and Co–Mo catalysts on the properties of MWCNTs is additionally investigated using the Raman spectroscopy in combination with measurements of the temperature dependence of conductivity. It is shown that MWCNT defectiveness depends on the active component composition for both Fe–Mo and Co–Mo catalysts. The current carrier concentration for the MWCNTs grown on Fe–Mo catalysts slightly increases with the Mo content. The opposite effect is observed for the tubes grown on Co–Mo catalysts, showing a decrease in the current carrier concentration with the increase of Mo concentration. [ABSTRACT FROM AUTHOR]