Atomic-Scale Analysis on the Role of Molybdenum in Iron-Catalyzed Carbon Nanotube Growth

We have elucidated the synergetic role played by molybdenum in iron-catalyzed chemical vapor deposition growth of carbon nanotubes (CNTs) by in situ environmental transmission electron microscopy. Molybdenum can be well accommodated by Fe-based carbide nanoparticle catalysts of M23C6-type structure (M = Fe and Mo). We have also shown that molybdenum suppresses the nucleation of iron compounds that are known to exhibit no catalytic activity for the growth of CNTs.