Remote-Contact Catalysis for Target-Diameter Semiconducting Carbon Nanotube Arrays

Abstract

Electrostatic catalysis uses an external electric field (EEF) to rearrange the charge distribution to boost reaction rates and selectively produce certain reaction products in small-molecule reactions (e.g., Diels–Alder addition), requiring a 10 MV/cm field aligned with the reaction axis. Such a large and oriented EEF is challenging for large-scale implementation or material growth with multiple reaction axes or steps. Here, we demonstrate that the energy band at the tip of an individual single-walled carbon nanotube (SWCNT) can be spontaneously shifted in a high-permittivity growth environment, with its other end in contact with a low-work-function electrode (e.g., hafnium carbide). By adjusting the Fermi level at a point where there is a substantial disparity in the density of states (DOS) between semiconducting (s-) and metallic (m-) SWCNTs, we achieve effective electrostatic catalysis for 99.92% purity s-SWCNT growth with a narrow diameter distribution (0.95 ± 0.04 nm), targeting the requirement of advanced SWCNT-based electronics for future computing.