The preparation of Al₂O₃/M (Fe, Co, Ni) nanocomposites by mechanical alloying and the catalytic growth of carbon nanotubes

Mechanical alloying was employed to produce Al₂O₃/M (M=Fe, Co, Ni) nanocomposites. It was found that high-energy mechanical milling could realize not only drastic refinement but also the well dispersion of catalyst precursors in oxide matrixes. After mechanical milling, the solid-state alloying and the accelerated substitutional reactions were observed between the parent oxides. The as-obtained Al₂O₃/M nanocomposites possessed the fine-grained and porous structures and thus high reducibility. Large-scale formation of multiwalled and single-walled carbon nanotubes were achieved by using these mechanical alloying-derived Al ₂O₃/M nanocomposites.