Rough porous N-doped graphene fibers modified with Fe-based Prussian blue analog derivative for wide-band electromagnetic wave absorption

With the rapid development of wireless communication technology, human living environments are being polluted by a large number of electromagnetic waves (EWs), and EWs absorption materials play an important role in exploring green living spaces. Carbon matrix composites derived from metalorganic frameworks (MOFs) are a new kind of EWs absorbing material with great application prospect. However, obtaining efficient absorbent with low filling rates and wide absorption bands remains a challenge. Here, we designed one-dimensional rough, and porous N-doped graphene fibers (N-GFs) that were assembled from two-dimensional graphene sheets with surfaces modified using a Fe-based Prussian blue analog (PBA) derivative. The rough porous structure optimized impedance matching characteristics of the absorber by introducing air gaps while the PBA particles improved N-GF electromagnetic parameters of N-GFs, increasing EWs absorption. The results showed optimal EWs absorption in the synthesized Fe-based PBA/N-GFs after annealing at 600 °C. At a filling rate of 10 wt%, the EWs absorption bandwidth could reach 8.19 GHz when the matching thickness was 2.1 mm; this covers most of the X radar frequency band and the entire Ku radar frequency band. The Fe-based PBA/N-GFs have a special microstructure and excellent EWs absorption properties, which provide inspiration for further exploration of graphene-based absorbing materials.