Fe Complex-Based Catalyst System for the Chirality-Selected Continuous Synthesis of Single-Walled Carbon Nanotubes

After decades of development, the single-walled carbon nanotube (SWCNT) has found its advantage in the application of logic devices and energy applications. However, the difficulty in the chirality-selected growth and mass production of the SWCNT impedes its commercial application, especially in field effect transistors (FETs) and solid-state electrodes used in lithium-ion batteries. The injection chemical vapor deposition (iCVD) is one of the most promising methods to realize the mass production of the SWCNT, during which the catalyst plays a key role in determining the diameter, wall number, and even chirality of as-grown carbon nanotubes. Here, an Fe complex-based catalyst system is designed to realize the chirality-selected continuous growth of the SWCNT. The introduction of NaCl can reduce the size of the formed localized liquid zones and enrich S atoms in these liquid zones, which contributes to the growth of the SWCNT. The different combinations of Fe(Ddtc)2(Phen) (Phen = 1,10-phenanthroline and Ddtc = diethyldithiocarbamate) and ferrocene then promote the growth of the SWCNT with different chiralities. The continuous growth progress confirms the high efficiency of this catalyst system, and the Raman and transmission electron microscopy (TEM) characterizations validate its effectiveness in the chirality-selected synthesis of the SWCNT. This study will provide an idea for the fine mass production of the SWCNT.