One-Step Pyrolytic Synthesis of Multiwalled Carbon Nanotubes: The Role of Resupply of Carbon Species on the Quality Control.

Abstract

An investigation on varying experimental parameters such as solution quantity (2.5, 5 and 7.5 mL) and reaction time (15, 30, 45 and 60 min) was carried out for the production of high-quality multiwalled carbon nanotubes (MWCNTs) in one step pyrolysis. Structural analysis revealed the uniform diameter distribution and the length of nanotubes in the range of 60-80 nm and 0.4-2 μm, respectively. Raman and X-ray diffraction analysis showed a remarkable reduction in defect density with increase in graphitization degree, upon increasing the solution volume and reaction time. MWCNTs prepared at higher solution quantity (7.5 mL) with higher reaction time (60 min) showed higher crystallinity (70% graphitization) and lower defect density (ID/IG: 0.56). The attainment in equilibrium of evaporation cum precipitation in formation of high quality nanotubes structure is evaluated. An effective resupplying of condensed precursors by re-evaporation leads for the achievement of low defect density nanotubes with higher product yield is achieved.