Rice straw-inspired tunable multi-hollow channel parallel carbon fibers for enhanced electromagnetic wave absorption

The pure carbon materials are constrained in practical applications due to their inability to meet the requirements of broadband and strong absorption. To address this challenge, inspired by the parallel connection structure of hollow straw, this study successfully fabricated a multi-hollow channel parallel carbon fibers (MHCFs) structure by electrospinning and carbonization template methods. Compared with the traditional nonporous carbon fibers (CFs) structure (MHCFs-0), MHCFs-0.2 exhibit more excellent electromagnetic wave (EMW) absorption performance. It exhibits an impressive 5.59 GHz effective absorption bandwidth (EAB) at 1.8 mm. The reflection loss (RL) of MHCFs-1 reaches -52.64 dB. This remarkable enhancement in performance can be attributed to the channel structure, which can effectively introduce air, optimize impedance matching, and greatly promote polarization effects (including interface polarization and dipole polarization). It is worth noting that the integration of computer simulation technology (CST) with material structure design in this study opens up new ideas for the preparation of absorbing materials and the design of micro-nano structures, holding significant practical implications.