Direct growth of carbon nanotubes with a catalyst of nickel nanoparticle-coated alumina powders

Ni nanoparticle-coated alumina ceramic powders were used as catalysts to synthesize carbon nanotubes (CNTs) with doped ceramic nanocomposites. The CNTs were prepared using microwave plasma-enhanced chemical-vapor deposition (MPECVD) with Ni nanoparticle-coated alumina powders using methane (CH₄) and hydrogen (H₂) gases. The CNTs were grown at different temperatures (400 ° C, 500 ° C, 600 ° C, and 700 ° C) to confirm the effect on the characterization of the process temperatures. CNTs were grown with different growth times (5, 10, 30, and 60 minutes) at 600 ° C to confirm the growth mechanism of the CNTs on alumina powders. Field emission scanning electron microscopy (FE-SEM) images showed growth trendsof the CNTs for various temperatures and growth times. High-resolution transmission electron microscopy (HR-TEM) images showed that the CNTs were randomly curved and that their shapes had bamboo-like multi-walled structures.