High-performance microwave absorption from biomass-derived porous helical carbon coils/FeNi composites

This study presents a novel porous helical carbon coils/iron-nickel alloy (HCCs/FeNi) composite, fabricated via an efficient catalytic graphitization process, which exhibits exceptional microwave absorption performance. By synergistically combining the unique porous helical architecture of biomass-derived carbon with the superior magnetic loss of FeNi alloys, the composite achieves an outstanding minimum reflection loss (RL min ) of -53.85 dB and a broad effective absorption bandwidth (EAB) of up to 5.16 GHz. This remarkable performance is attributed to synergistic mechanisms involving the distinctive helical and porous structure, abundant structural defects, optimal impedance matching, and multiple polarization relaxations. Our work not only underscores the great promise of biomass-derived carbon structures for electromagnetic wave absorption but also provides a viable design strategy for developing high-performance broadband microwave absorbers.