Growth and Field Emission Characteristics of Carbon Nanotubes Using Co/Cr/Al Multilayer Catalyst

Abstract

A multilayer catalyst, Co/Cr/Al, was employed to synthesize carbon nanotubes (CNTs) at atmospheric pressure by thermal chemical vapor deposition (thermal CVD). The relative growth rates, calculated on the basis of the average lengths of nanotubes grown at different temperatures, were utilized to estimate an activation energy of 0.84 eV for the multilayer catalyst. Such a low activation energy implies that the nucleation and growth of nanotubes could be effectively enhanced via the multilayer catalyst due to the well-distributed small catalytic nanoparticles by Al supporting layer and higher activity by Cr co-catalyst layer. It was also found that nanotubes grown using this configuration at 500 °C exhibited excellent field emission characteristics, and showed a highly uniform emission image in a phosphor-coated anode plate.