Narrow-chirality distributed single-walled carbon nanotube synthesized from oxide promoted Fe–SiC catalyst

Abstract

A SiC supported iron (Fe–SiC) catalyst was developed for chemical vapor deposition (CVD) growth of carbon nanotubes. Using CO as the carbon source, sole Fe–SiC catalyst was mostly inactive for synthesizing carbon nanotubes and only trace amount of carbon deposits was produced. In contrast, the powder Fe–SiC catalyst could be activated by pressing them onto a flat SiO2 substrate or by mixing them with porous MgO powders. Particularly, efficient growth of single-walled carbon nanotubes (SWNTs) was achieved on porous MgO promoted Fe–SiC catalyst, and predominant synthesis of (6, 5) SWNTs was realized at a reaction temperature of 650 °C. Systematic characterizations revealed that the reducibility of the Fe–SiC catalyst was enhanced by the physical contact with oxide support, which promotes the formation of small active Fe nanoparticles for the subsequent SWNT nucleation and growth. This work not only deepens our understandings to the catalyst activation mechanisms, but also helps design composite catalyst for synthesizing SWNTs.