Rational design of hollow rice-grained α-Fe₂O₃/carbon nanofibers with optimized impedance matching for electromagnetic wave absorption enhanced

Electromagnetic wave absorption materials are widely used in electronic equipment and military fields. However, high cost and complex preparation processes become a major obstacle in promoting popularization in the civil field. To solve the problems above, researchers have made great efforts to develop Fe-based carbon composites. However, most of the typical composites require a high filling ratio while achieving excellent properties. Therefore, in this study, carbon nanofibers (CNFs) combined with the hollow rice-grained α-Fe₂O₃ nanoparticles were prepared by the in-situ transformation method. The rational microstructure design provided a solution for reducing the filling ratio, optimizing impedance matching, and improving electromagnetic wave absorption performance. The strong reflection loss value (−38.1 dB) and broad effective absorption bandwidth (4.6 GHz) for Fe₂O₃/CNFs composites were achieved with a low filling ratio (20 wt.%), and the analysis of electromagnetic parameters validated that the microstructure of Fe₂O₃/CNFs plays a crucial role in the performance improvement. With the optimized impedance matching and simple preparation method, Fe₂O₃/CNFs have broad application prospects in electromagnetic wave absorption.