Graphene-like structure of bio-carbon with CoFe Prussian blue derivative composites for enhanced microwave absorption

Traditional carbon materials such as graphene are often applied in the field of electromagnetic wave (EMW) absorption but they have unbalanced impedance matching and high conductivity. Bio-carbon with graphene-like structure derived from apples has many advantages over graphene: it can be prepared in large quantities and the abundant heteroatoms present in the lattice can provide many polarization phenomena. Herein, Prussian blue analogue (PBA) as a source of magnetic component was combined with bio-carbon or reduced graphene oxide (rGO) to study the EMW absorption properties. The fabricated BC/CFC-12-7 displayed performance with a minimum reflection loss (RL_min) of -72.57 dB and a wide effective absorption bandwidth (EAB) of 5.25 GHz with an ultra-thin and nearly equal matching thickness at 1.61 mm. The results show that the good EMW absorption property of bio-carbon composites comes from good conduction loss, large relaxation polarization loss especially from pyridinic-N, and better impedance matching. The optimized radar cross section is found to be -33.55 dB m² in the far-field condition using CST. This work explored the advantages of bio-carbon as a novel EMW absorbing material compared with graphene and provided ideas for realizing high-performance EMW absorbing materials in the future.