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The article presents the results of experiments on the synthesis of carbon nanofibers by thermal chemical vapor deposition using copper nanopowders obtained by electric explosion of wire as catalysts. Stable growth of carbon nanofibers was carried out at temperatures significantly lower than normally used. The process parameters that are optimal for low-temperature growth of carbon nanofibers have been identified during the performed experiments. The synthesized samples have different diameters and morphology (from spiral to direct). Copper clusters are both at the ends and inside the fibers. The results of IR spectroscopy indicate that the structure of the obtained carbon nanofibers is polymeric. X-ray analysis revealed the presence of a halo on the diffraction patterns at small values of the angle 2θ, which proves that the grown structures have an amorphous nature. There are no groups that are responsible for long-range order in all Raman spectra. Studies by transmission electron microscopy showed that nanostructures do not have an internal channel and nanofibers are solid.

This work presents the results of experiments on synthesis of carbon nanostructures by the method of thermal chemical vapor deposition using iron nanopowders obtained by the method of electrical explosion of wires as catalysts. To study the process of nucleation and growth of individual carbon nanostructures, experiments were conducted not only on nanopowders, but also on the separated clusters. To determine the optimum conditions of the carbon nanostructures synthesis and lower temperature limit, experiments were performed at different temperatures (300–700 °C) and pressures (100–400 mbar). The experiments have shown that the lower temperature limit for carbon nanostructures synthesis on the iron nanopowders is 350 °C and in this process the growth of carbon nanostructures is not so massive. Stable growth of carbon nanostructures for nanopowders as well as for the separated clusters began from 400 °C during the entire range of pressures. In contrast to the carbon nanostructures on nanopowders, in the case of the separated clusters a strong<br />dependence of their nucleation and growth on temperature and pressure was traced.

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