Researchers introduced a novel single-step method for synthesizing nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) decorated with iron (Fe) and copper (Cu) nanoparticles directly on copper foil substrates. EDS analysis indicated atomic concentrations of carbon (C, 83.82%), Fe (10.94%), Cu (0.92%), and oxygen (O, 4.32%). At 850-950 °C synthesis temperatures, larger tubular-defective fiber-type carbonaceous aggregates (~500 nm) were produced with fewer CNTs. Applications of N-Doped Carbon NanotubesThe synthesized hybrid materials have significant potential for use in energy storage devices, primarily supercapacitors. The optimal temperature of 800 °C produced bamboo-shaped N-MWCNTs decorated with Fe and Cu nanoparticles, showing high carbon content and excellent capacitive behavior.