The Effect of Different Temperature Profiles Upon the Length and Crystallinity of Vertically-Aligned Multi-Walled Carbon Nanotubes

We synthesized vertically-aligned multi-walled carbon nanotubes with an inner diameter of 1.6 similar to 7.5 nm and stack height of 80 similar to 28600 mu m by chemical vapor deposition. The effects of synthesis conditions such as substrate position in the tube furnace, maximum temperature, temperature increasing rate and synthesis duration on the structure of nanotubes were investigated. It was found that slightly faster temperature increase rate resulted in significantly longer length, larger diameter and more defects of nanotubes. Structural parameters such as inner, outer diameters, wall thickness and defects were investigated using transmission electron microscopy and Raman spectroscopy.