Synthesis of Beaded and Entwined Carbon Nanofibers in Ni:Al Alloy Catalyst

This paper reports two new types of carbon nanofibers synthesis by thermal decomposition of n-hexane in presence of Ni–Al alloy in hydrogen atmosphere at 1100 C. One type is “beaded fibers” in which spherical carbon beads (∼1 m) are regularly grown from outer surface of fibers (∼0.3 m). The other new microstructure is “entwined fibers ” in which multiple nanofibers of diameter ∼100 nm grow self-entwined like a braid of hair. Both bead-fiber bonding (in beaded fibers) and fiber–fiber interaction (in entwined fibers) are strong to be detached/unfolded by 30-min ultrasonication