Biomass-derived carbon heterostructure composites modified with magnetic iron oxide for excellent EMW-absorbing materials

With the gradual spread of satellite navigation, broadcasting, and communication technologies, the problem of electromagnetic pollution in C- and Ku-band has increased. Electromagnetic wave (EMW) absorbing materials can effectively mitigate this problem. Here, we report the design of a biomass carbon heterostructure for the absorption of EMWs. This design takes advantage of the natural fiber mesh structure of the loofah and the voids, veins, and basal tissues surrounding the fibers. The material is then carbonized to create a radar antenna-like structure of fibers and nanosheets. This improves the material's conductive loss. In addition, modification with magnetic iron oxide in loofah sponges improves the impedance matching of the materials, enhances the magnetic loss, and increases the heterogeneous interface. We found that the maximum effective absorption frequency range of the prepared EMW-absorbing materials is 3.80 GHz, which is mainly concentrated in the C band and Ku -band, and its maximum | RL min | value is -59.20 dB. The material's ability to absorb EMWs was also verified by simulating the radar cross section (RCS). In conclusion, this work develops a green and efficient composite material for absorbing EMWs and provides new design ideas for the development of EMW-absorbing materials.