Extended alcohol catalytic chemical vapor deposition for efficient growth of single-walled carbon nanotubes thinner than (6,5)

Abstract

We performed a comprehensive exploration on alcohol catalytic chemical vapor deposition (ACCVD) synthesis of single-walled carbon nanotubes (SWCNTs), and with more than 70 temperature-pressure sets, we presented an extended ACCVD parametric map that covers a wide range of temperature from 340 to 950 °C and a wide pressure range over 6 orders of magnitude. Efficient synthesis of high quality SWCNTs becomes possible at temperatures down to 400 °C and pressure as low as 10−2 Pa, which benefits from the strong correlation between temperature and pressure newly discovered in this exploration. The underlying mechanism is clarified through a kinetic model, and two growth boundaries on the extended experimental map are explained by a transfer-free transmission electron microscopy (TEM) observation. Most importantly, after extending growth window of ACCVD, successful synthesis at extreme low temperature and pressure gives a significantly enhanced yield for super-small diameter SWCNTs (0.8 nm > dt > 0.62 nm) thinner than (6, 5) that are rarely observed from direct synthesis.