Tunable porous structure Co/Carbon nanofibers with excellent electromagnetic wave absorption properties

Magnetic metal/porous carbon nanofibers (CNFs) have emerged as a focal point in the study of electromagnetic wave absorbing materials because of their combined electromagnetic losses, multiple scattering, and long attenuation paths. In this work, we prepared porous Co/CNFs using electrospinning integrated with the thermal carbonization process and controlled the porous structure and fiber microwave absorption characteristics by varying the amount of zinc acetate added to the spinning solution. High temperatures led to the volatilization of Zn, creating pores and defects. This process not only increased dipole and interface polarization but also contributed to the reduction of electromagnetic waves (EMWs). When the additive amount of zinc acetate was 0.15 g, the porous Co/carbon nanofibers achieved a smallest reflection loss (RL) of −42.7 dB and an effectively bandwidth (EBW) of 4.48 GHz at a thickness of 2.5 mm. This work provides a new approach for obtaining efficient and lightweight microwave absorbing materials.