Synergistic effects in FeCu bimetallic catalyst for low temperature growth of single-walled carbon nanotubes

A series of MgO-supported FeCu catalysts with different metal concentrations has been studied for synthesizing single-walled carbon nanotubes (SWCNTs). Spectroscopic characterization results have revealed that the concentrations of Fe and Cu are crucial for the purity of the produced SWCNTs, but have little effect on the SWCNT chirality distributions. The synergistic mechanisms of Fe and Cu in the catalysts were discussed and used for interpreting the growth results. Guided by the roles of Cu, an MgO-supported CoCu catalyst was also developed for low temperature growth of small diameter SWCNTs. All the results indicate that the Cu phase inhibits the sintering of the reduced metal particles and the active Fe or Co nanoparticles determine the chirality distribution of the SWCNTs.