Selective synthesis of (9,8) single walled carbon nanotubes on cobalt incorporated TUD-1 catalysts.

Selective synthesis of single walled carbon nanotubes (SWCNTs) with specific (n,m) structures is desired for many potential applications. Current chirality control growth has only achieved at small diameter (6,5) and (7,5) nanotubes. Each (n,m) species is a distinct molecule with structure-dependent properties; therefore it is essential to extend chirality control to various (n,m) species. In this communication, we demonstrate the highly selective synthesis of (9,8) nanotubes on a cobalt incorporated TUD-1 catalyst are (Co-TUD-1). When catalysts were prereduced in H(2) at the optimized temperature of 500 °C, 59.1% of semiconducting nanotubes have the (9,8) structure. The uniqueness of Co-TUD-1 relies on its low reduction temperature (483 °C), large surface area, and strong metal-support interaction, which stabilizes Co clusters responsible for the growth of (9,8) nanotubes. SWCNT thin film field effect transistors fabricated using (9,8) nanotubes from our synthesis process have higher average device mobility and a higher fraction of semiconducting devices than those using (6,5) nanotubes. Combining with further postsynthetic sorting techniques, our selective synthesis method brings us closer to the ultimate goal of producing (n,m) specific nanotube materials.