The effects of catalyst preparation techniques and synthesis temperature on the production of carbon nanotubes by the CVD method

Abstract. The effects of synthesis temperature and catalyst preparation conditions for the production of carbon nanotubes were investigated using the CVD method with C~ as carbon feedstock. Two Ah0 3-Fe catalyst aerogels were prepared using the same starting materials (aluminium nitrate and ferric sulphate) and ratios; aerogel 1 was dried normally while aerogel 2 was supercritically dried. CNTs were produced by direct pyrolysis of methane over the catalyst for 30 minutes at a range of different temperatures. Aerogel l produced better quality and higher yield ofMWCNTS and bundles ofSWCNTs at lower temperatures than aerogel 2 catalyst. The yield ofNTs for aerogel 2 was observed to increase with temperature.