Nitrogen Doping Effects on Microstructure of Multi-Walled Carbon Nanotubes

Abstract

Taking Fe/NaY zeolite as catalysts, a range of nitrogen doped carbon nanotubes (N-CNTs) were synthesized by chemical vapor deposition method (CVD) at 1073K using ethanediamine, dimithylethanediamine and tetramethyl ethanediamine as nitrogen source and carbon source, respectively. The structural and compositional properties of N-CNTs were characterized by XRD, SEM and TEM. The results illustrate the microstructure of N-CNTs is strongly dependent on the N/C ratio of precursors. With the increase of N content in precursors, N-CNTs became shorter, more disorder, coarser surface and the average bamboo segment distance increased from 40 nm to 60 nm. A mechanism for the formation of the N-CNTs grown from three precursors with different N/C ratio has been proposed based on experimental observations.