Carbon nanotube growth in the pores of expanded graphite by chemical vapor deposition

The growth of carbon nanotubes (CNTs) in the pores of expanded graphite by chemical vapor deposition with and without a catalyst was investigated and their microstructure was studied by scanning electron microscopy. Results show that pores of the expanded graphite, which can load catalyst particles, is the physical base for the growth of CNTs. Co(NO3)2 is better than Fe(NO3)3 and Ni(NO3)2 when used to immerse expanded graphite. The optimum catalyst concentration is 0.025 mol/L Co(NO3)2. The active edges of graphenes of freshly expanded graphite is a key factor for the growth of CNTs under non-catalytic conditions.