Heterogeneous network constructed by high aspect-ratio Kapok biomass microtube for lightweight and broadband microwave absorbent

Network-structured carbon materials are considered as a practical path to improve impedance matching. While one-dimensional carbon materials with unique large aspect ratio, can highly facilitate the construction of qualified network structures. Inspired by the naturally evolved biomass conduit system, we developed a novel Fe₂O₃@carbon microtube network (FN@CMT) with centimeter-level Kapok microtube as precursor, Fe₂O₃ nanoparticles as decoration. Notably, FN@CMT exhibits excellent absorption bandwidth of 7.09 GHz at ultralow filling ratio of 7.69 wt%, covering 88% of the Ku band. Such excellent EMW performance can be attributed to its unique 1D carbon microtube unit constructed network structure along with heterogeneous interfaces from Fe₂O₃ nanoparticles cluster. This investigation provides a new prototype for the development of novel EMW absorbing networks by taking advantages of the high aspect ratio one-dimension Kapok microtube unit.