Synthesis of Vertically Aligned Carbon Nanotubes with Different Diameters in Porous Alumina Template via a Simple CVD Method

Vertically aligned carbon nanotubes(VACNTs) within the cylindrical pores of anodic aluminum oxide (AAO) template which are fabricated by chemical vapor deposition (CVD), are synthesized in this work. AAO templates with different pore diameters of 20-210nm have been used to produce VACNTs. Acetylene and argon were used in a CVD reactor (1100 mm long and 50 mm wide), at 600-650oC for 4 hours and the flow ratio of Acetylene/Ar has been considered in the range of 0.05-0.1. The results show that when the flow ratio of Acetylene/Ar is more than 0.1, no formation of VACNTs is observed in the hole of AAO template. It is also found that the surface holes of the AAO template become close when the reactor temperature increases up to 650oC. Scanning electron microscope(SEM), transmission electron microscope(TEM) and Raman spectroscopy were employed to characterize the AAO templates and aligned CNTs.