Synthesis and characterization of carbon fibrils formed by stacking graphite sheets of nanometer thickness

Carbon fibrils with length of 2-3 μm formed by stacking graphite sheets of ∼10-40 nm in thickness along the 〈0 0 1〉 direction were prepared by pyrolysis of tetrahydrofuran at 600 °C in the existence of metallic nickel. The spacing of adjacent sheets concentrated on ∼3.8 nm and ∼50 nm. Metallic nickel played a catalytic role in the formation of carbon fibrils, and a possible formation process was proposed.