Biomass-derived ferrous magnetic carbon-based nanocomposites from loofah collaterals for excellent electromagnetic wave-absorbing materials

High-performance wave-absorbing materials are always pursuing the goals of thin, lightweight, wide and strong absorption. Hitherto carbonaceous materials are still one kind of the most popular wave-absorbing materials. This work proposed a facile biomass-derivation route to prepare carbonaceous wave-absorbing materials. Loofah collaterals were impregnated with Fe(NO3)3 solution, and a process of iron-catalyzed carbonization for the dried precursors ensued, leading to the formation of Fe@Fe3C/C ternary nanocomposites. It's found that the Fe@Fe3C/ C nanocomposites possessed the absorption abilities from 13.0 to 18.0 GHz with the effective absorbing bandwidth almost covered the Ku band. The superior wave-absorbing properties were mainly ascribed to the synergism of dielectric and magnetic loss mechanisms. Meanwhile, the improved impedance matching and the elevated attenuation ability also favored the strong absorption at specific thickness. This work paved the way for the green synthesis and mass production of high-efficient wave-absorbing materials, and further inspired the regeneration of biomass waste for electromagnetic applications.