Aligned Bundles of Carbon Nanotubes Are Easily Grown on As-Synthesized Mesoporous Silicate Substrates

Abstract

As-synthesized mesoporous silicates have been used as substrates for the growth of aligned bundles of carbon nanotubes. The as-synthesized mesoporous silicates facilitate the growth of a rich yield of carbon nanotubes in a manner that does not occur on their calcined analogues. The growth of the nanotubes was performed via chemical vapor deposition at 800 °C with acetonitrile as precursor. The Fe metal catalyst was incorporated onto the silicate mesophases via impregnation rather than the more conventional direct-mixed-gel synthesis. Alumination, via postsynthesis grafting of the as-synthesized mesoporous silica substrates, enhances the production of carbon nanotubes and favors their growth in aligned bundles. This is the first time that as-synthesized mesoporous silicates have been used as substrates to successfully grow large amounts of carbon nanotubes. The approach described is simple, avoids the need for calcining the substrate and offers further advantages including higher yields of carbon nanotubes and the attractive formation of well aligned bundles of nanotubes.