Selective Growth of Single-walled Carbon Nanotubes using Cobalt Disilicide

After chirality-specified growth of single-walled carbon nanotubes (SWCNTs) was realized by tungsten-based intermetallic compound catalysts, here we developed a different kind of intermetallic compound, cobalt disilicide (CoSi2), as catalysts to selective grow carbon nanotubes by chemical vapor deposition (CVD). By using methane as carbon source, we obtained (11, 7) tubes with the selectivity of similar to 24% and semiconducting SWCNTs (s-SWCNTs) with the purity of similar to 93% simultaneously. Because of the sensitivity of CoSi2 toward the oxygen-containing environment at high temperatures, ethanol is not a good carbon feedstock. Our results not only expand the chirality library and catalyst database in the chirality-selective synthesis of SWCNTs, but also further demonstrate the feasibility of intermetallic compound catalysts.

Automated summary

In this study, a new intermetallic compound catalyst, CoSi2, was developed for the selective growth of carbon nanotubes by chemical vapor deposition. The catalyst showed high selectivity for the synthesis of (11, 7) tubes and high purity of semiconducting SWCNTs. However, ethanol is not suitable as a carbon feedstock due to the sensitivity of CoSi2 to oxygen-containing environments at high temperatures.