In general CNFs are produced by high temperature
In general, CNFs are produced by high-temperature catalytic chemical vapor deposition (CCVD) of carbon-containing gases over small transition metal (e.g. iron, nickel, and cobalt) nanoparticles (NPs) , , ,  and . Correspondingly, metal NPs can be located at the tips or in the bodies of CNFs, leading to the formation of metal–CNFs composite materials. Recently, we showed that Amrubicin CNFs were synthesized over supported metal catalysts derived from layered double hydroxides (LDHs)  and . LDHs with the general formula [M1−x2+Mx3+(OH)2]x+[Ax/n]n− · mH2O are known as a family of highly ordered two-dimensional layered materials  and , which consist of positively charged layers and negative anions in the interlayer. Therefore, well-dispersed metal catalysts may be formed by reducing calcined LDHs , ,  and . Currently, we have explored the generation and stabilization of highly dispersed nickel NPs via either the reduction of NiAl-LDH precursor supported on carbon nanotubes or in situ self-reduction of hybrid composite of NiAl-LDH and carbon  and .