Magnetic Porous Carbon Composites for Efficient Electromagnetic Wave Absorption

Biomass carbon composites have the shining points of lightweight, economy, harmlessness, and large specific surface area, casting on them great development prospects in terms of excellent wave absorbing properties. Herein, a facile route to fabricate magnetic porous with a special spongy structure for its great contribution to microwave absorption is reported. It is endowed with a strong absorption capacity and a wide absorption band. The 3D spongy structure and uniform distribution of magnetic Co particles can promote defect polarization, interface polarization, and dipole polarization, which are conducive to scattering and reflection of electromagnetic waves (EMW) in the absorbing body. The magnetic Co particles can enhance the magnetic loss on the one hand and harmonize the impedance matching on the other hand. The minimum reflection loss can reach −54.7 dB. The effective absorption bandwidth at 2.1 mm can reach 7.61 GHz, almost covering the X and Ku bands. This proposed strategy provides more possibilities for the application of biomass microwave absorbers with lightweight and broadband properties.