Lightweight and Efficient Microwave-Absorbing Materials Based on Loofah-Sponge-Derived Hierarchically Porous Carbons

Lightweight, low-cost, and effective microwave-absorbing materials are important in electronics, communication, and military defense. Recently, microwave-absorbing materials stemming from biomass have drawn increasing attention for their sustainable properties, low cost, and high performances. In this work, loofah-sponge-derived carbon/CoFe 2 O 4 composites have been prepared by functionalization and subsequent pyrolysis treatment. The porous composites prepared from the loofah sponge exhibit a typical lotus-root-like structure with low density. The composites exhibit an efficient absorption value of −43.8 dB at 8.3 GHz (X band) with a thickness of 3 mm. The high-performance absorption is ascribed to the synergistic attenuation effect of magnetic nanoparticles and dielectric lotus-root-like carbon substrate. The obtained results demonstrated that the loofah-sponge-derived carbon/CoFe 2 O 4 composites with lotus-root-like microstructure have great potential to be lightweight and low-cost microwave-absorbing materials at elevated temperature.