Synthesis and characterization of Cobalt/Calcium Carbonate catalyst in the production of carbon nanotubes

Abstract

Since its discovery, carbon nanotubes (CNTs) have been widely researched owing to their large potential in nanotechnological applications. The effects of catalyst calcination behavior (temperature and duration) on the production of CNTs synthesized via chemical vapor deposition (CVD) were studied. The catalysts were prepared through co-precipitated technique by mixing Co salt and CaCO3 powder which was then calcined at various temperatures followed by methane decomposition process to grow CNTs on CaCO3 support. The temperatures were selected based on TGA analysis of uncalcined catalyst. The optimum temperature was chosen and proceed with a variation of calcination durations. Results showed that the CNTs products are found to be Type II isotherm with their surface areas in the range of 2.77 to 68.77 m2/g. It was also noteworthy that the catalyst calcined at 500 °C for 10 hours had successfully yielded a high amount of CNTs as judged by scanning electron microscopy (SEM) whereas less traces of CNTs were detected for catalyst calcined at 300 °C and 700 °C respectively with a decreasing trend of crystallite size according to the calculation of Debye-Scherrer equation.