Controlled growth of carbon nanotubes in diameter and shape using template-synthesis method

A template-synthesis technique based on self-ordered hexagonal nanopore alu mina templates was applied for synthesizing highly ordered carbon nanotube arrays via thermal decomposition of ethylene with iron as catalyst electrod eposited into the bottom of the pores. It was found that the resultant carb on nanotubes in diameter and shape exactly reflect the pore of the template used. This shows that the diameter of nanotubes can be easily controlled a nd adjusted through the pore sizes of the templates, and the nanotubes with various shapes can be grown by applying templates with the same pore shape s as those of the tubes. This controllable synthesis method will be of grea t fundamental and practical interests. (C) 2001 Elsevier Science B.V. All r ights reserved.