Electromagnetic wave (EMW) absorbing materials are crucial for electronics and health, but face challenges like impedance mismatch and limited EMW attenuation. Here, Fe 2 O 3 /carbon fibers (C f ) composites were synthesized via a one-step hydrothermal method using FeCl 3 ·6H 2 O and C f as raw materials. The phase composition and microstructure of Fe 2 O 3 /C f composites were systematically analyzed. The C f content was varied to regulate the electrical conductivity of Fe 2 O 3 /C f composites. Additionally, the effects of Fe 2 O 3 /C f content on electromagnetic (EM) parameters, conductivity, and EMW absorption characteristics of Fe 2 O 3 /C f /paraffin composites were investigated. The results indicate that with 18.42 wt.% C f , the Fe 2 O 3 /C f /paraffin composites exhibited the optimal electrical conductivity for EMW absorption. When the mass fraction of Fe 2 O 3 /C f is 30 wt.%, the Fe 2 O 3 /C f /paraffin composites achieved a minimum reflection loss (RL min ) of −34.38 dB with a thickness of 1.80 mm, and an effective absorption bandwidth (EAB, RL < −10 dB) of 4.06 GHz when the thickness is 1.60 mm, demonstrating notable advantages in both EAB/ d and RL min / d . This is due to appropriate C f content, which enables tunable electrical conductivity in the Fe 2 O 3 /C f /paraffin composites, leading to excellent impedance matching characteristics. Moreover, the synergism between magnetic and electrical losses effectively strengthens the EMW attenuation. This research provides a viable approach for producing high-efficiency EMW absorbing materials. • Tuning C f content in Fe 2 O 3 /C f optimizes impedance matching and EMW attenuation • Fe 2 O 3 /C f /paraffin achieves the RL min of −34.38 dB and EAB of 4.06 GHz (RL < −10 dB) • Synergistic mechanisms of conductive, dielectric, and magnetic losses were clarified
Liu et al. (Sun,) studied this question.