A simple and room temperature sol–gel process for the fabrication of cobalt nanoparticles as an effective catalyst for carbon nanotube growth

Abstract

Cobalt catalyst thin films were prepared on silicon wafers using a spin coating process. The detailed structural characteristics of the cobalt films/particles and synthesized carbon nanotubes were studied using X-ray analysis, high resolution electron microscopy, and Raman spectroscopy. The thickness of the catalyst thin films can be controlled by controlling the spin coating parameter, and the thickness of the films can be reduced by increasing the spin speed. Cobalt catalyst particles can be achieved by post-heat treatment within the range of 450–600 °C. However, increasing the post-heat treatment temperature may lead to larger particle formation. The optimum values of thin film thickness and particle size were 12.1 nm at 8000 rpm and 10.6 nm at 450 °C, respecively. The study also demonstrated that single-walled carbon nanotubes could be grown from cobalt catalyst particles via catalytic chemical vapor deposition of ethanol.