Comparative Structural Characterization of Multi-Walled Carbon Nanotubes Synthesized by Electro-Thermal Explosion and Self-Propagating High-Temperature Synthesis

The synthesis of multi-walled carbon nanotubes (MWCNTs) through rapid energy-release processes has attracted increasing attention due to its scalability and reduced production cost compared with conventional chemical vapor deposition routes. In this study, MWCNTs were synthesized using Electro-Thermal Explosion (ETE) and Self-Propagating High-Temperature Synthesis (SHS) approaches. Structural characterization was performed using X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). XRD analysis confirmed the presence of graphitic carbon with characteristic reflections near 26.5° and 44°. TEM observations revealed well-developed multi-walled tubular structures with internal diameters ranging from 2–10 nm and external diameters between 10–50 nm. Raman spectroscopy demonstrated structural differences between synthesis routes, with ETE-derived nanotubes exhibiting a higher defect density than SHS-derived nanotubes. These findings demonstrate that energy-release kinetics significantly influence graphitization and defect formation in carbon nanotube structures.