Design and synthesis of magnetic porous carbon nanofibers with excellent microwave absorption

• The porous Ni/NiO/CNFs were fabricated through the electrospinning method. • The straightly introduction of SiO 2 could simplify the process. • The porous structure was applied to enhance the EMW attenuation. • The optimal RL reached −47.9 dB with a thickness of 3.0 mm (10 wt% filling ratio). The magnetic porous carbon nanofibers (CNFs) are highly desirable due to the excellent reflection loss (RL) and impedance matching in microwave absorption applications. Herein, the porous Ni/NiO/CNFs were fabricated by electrospinning combined with vacuum calcination and etching technology. Porous Ni/NiO/CNFs with different electromagnetic (EM) parameters and impedance matching could be easily obtained by adjusting the calcination temperature. On account of the synergistic loss mechanism composed of magnetic loss and dielectric loss leads to excellent impedance matching, the porous structure caused multiple reflection and scattering of incident electromagnetic waves (EMW), combined with the polarization loss between different components, the as-prepared materials exhibited enhanced EMW absorbing property compared with traditional microwave absorbers (MAs). The resulting porous Ni/NiO/CNFs obtained at 650 °C exhibited the optimal EMW absorption performance with an RL of −47.9 dB at 9.5 GHz and broad effective absorption bandwidth (EAB) of 3.5 GHz with a thickness of 3.0 mm. This work provides a mentality for multi-component loss mechanism and rational structure design of CNFs-based absorbing materials.