Fe3C/Fe@N-doped porous carbon composites with excellent microwave absorption properties

Biomass derived porous carbon has attracted extensive attention in microwave absorption and shielding due to its unique structure and low cost. However, it is a great challenge to improve the impedance matching of electromagnetic wave absorbers by adjusting the distribution of magnetic particles and pore structure. In this research, Fe3C/Fe@N-doped biomass-derived porous carbon composites (Fe3C/Fe@NBPC) is successfully pre-pared by swelling-freeze-drying and carbonizing. It is worth noting that the uniform distribution of magnetic particles is achieved through the swelling process. The impedance matching performance of Fe3C/Fe@NBPC is effectively improved by adjusting the aperture and doping magnetic particles. The heterogeneous magnetic/ dielectric multi-component benefit to superior EMW absorption performance through forming multiple polari-zations, magnetic loss, and dielectric loss effects. The optimal Fe3C/Fe@NBPC composites exhibits superior electromagnetic wave (EMW) absorption performance with the minimum reflection loss value of -52.25 dB and wide effective absorbing bandwidth of 3.06 GHz at 2.71 mm matching thickness. This work provides guidance for designing an efficient biomass derived EMW absorber with low cost, light weight and strong absorption.