The influences of synthesis time on the growth of CNTs over Ni/Al catalyst by CVD

摘要

Carbon nanotubes (CNTs) had been synthesized in different time by catalytic decomposition of methane over Ni/Al catalyst by chemical vapor deposition at 550℃. After 5min decomposition of methane, the CNTs showed less crystallinity and tubular graphite sheets. At the same time, the shape of nickel particle had changed from quasi-sphere to quasi-cone. As synthesis time was prolonged to 30min, the CNTs with better crystallinity and herringbone structure could be achieved and nickel particle became more standard cone-shaped. The interaction between the CNTs and nickel particle might take place during the synthesis. A simple model for the growth of herringbone CNTs and the distortion of nickel particle was hypothesized.