Kinetics-Controlled Growth of Metallic Single-Wall Carbon Nanotubes from CoRex Nanoparticles

The controlled growth of metallic single-wall carbon nanotubes (m-SWCNTs) is very important for the fabrication of high-performance interconnecting wires, transparent conductive electrodes, light and conductive fibers, etc. However, it has been extremely difficult to synthesize m-SWCNTs due to their lower abundance and higher chemical reactivity than semiconducting SWCNTs (s-SWCNTs). Here, we report the kinetically controlled growth of m-SWCNTs by manipulating their binding energy with the catalyst and promoting their growth rate. We prepared CoRe4 nanoparticles with a hexagonal close-packed structure and an average size of ∼2.3 nm, which have a lower binding energy with m-SWCNTs than with s-SWCNTs. The selective growth of m-SWCNTs from the CoRe4 catalyst was achieved by using a low concentration of carbon source feed at a relative low temperature of 760 °C. The m-SWCNTs had a narrow diameter distribution of 1.1 ± 0.3 nm, and their content was over 80%.