Carbon Nanotubes with Tailored Amorphous Graphitic Components for Electromagnetic Wave Absorption

Carbon nanoframeworks have received considerable attention in electromagnetic wave absorption (EWA), benefiting from their low mass density, cost effectiveness, environmental friendliness, and strong mechanical strength. Although various works have been performed to achieve carbon nanostructures with favorable electromagnetic behavior, the mechanism behind the application is still ambiguous, typically the effect of amorphous and graphitic components on the EWA performances. Accordingly, we modulate carbon nanotubes with a controllable amorphous–graphitic ratio based on a facile carbonization strategy. With the increased processing temperature, CNTs show increased graphitic formation simultaneously with the removal of amorphous carbon. Meanwhile, the N-containing groups are also converted from defective N toward graphitic N. The optimum performance is achieved with a strong reflection loss (−61.25 dB) and broad bandwidth (6.24 GHz) at 700 °C. Simulation is further applied to demonstrate the effects of CNTs with different amorphous–graphitic ratios. Such work elucidates the impact mechanism of amorphous and graphitic carbon on the electromagnetic behavior, resulting in the scalable application of carbon materials.