CCVD synthesis of carbon nanotubes (CNTs) using MgO and CaCO3 supports

Abstract

Carbon nanotubes or CNTs are graphene sheets that are rolled into nano-sized tubes. It has unique physical and electrical properties and has a lot of potential in research and practical applications. In this work, carbon nanotubes have been synthesized using catalytic chemical vapor deposition (CCVD) method. This method has been identified as one of the most promising methods for large-scale CNT production. The catalysts used are Fe/Co bimetallic catalysts on magnesium oxide and calcium carbonate supports. The carbon source used is the acetylene gas. The nanotubes produced by the CCVD method are then treated with nitric acid in order to remove impurities such as carbonaceous matter, catalyst particles and catalyst support. The as-produced and purified CNTs were analyzed with scanning electron microscope (SEM), field-emission SEM (FE-SEM) and energy dispersive X-ray analysis (EDAX). The analysis results show that Ca and Mg salts are able to become supports in successful CCVD synthesis with Fe/Co catalyst. It also proves that acid treatment is capable of removing the catalyst particles and catalyst support from the magnesium oxide and calcium carbonate-supported CNTs.