Аннотация: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.