Mn ₃ O ₄ Nanoparticles Anchored on Carbon Fiber for Enhanced Absorption Shielding Effectiveness

ABSTRACT Many kinds of electromagnetic shielding materials have garnered growing attention for their crucial role in mitigating electromagnetic radiation. The coupling of transition metal oxides and carbon materials for achieving synergistic electromagnetic interference shielding effectiveness (EMI SE) has become a prominent research direction. As a typical carbon material, carbon fiber (CF) features high electrical conductivity, low density, flexibility, and weavability, making it an ideal electromagnetic shielding material. In this work, Mn ₃ O ₄ /CF composite is fabricated via a hydrothermal method, driven by electrostatic attraction between Mn ²⁺ and CF. The EMI SE of the flexible Mn ₃ O ₄ /CF/PDMS (polydimethylsiloxane) (~0.36 mm) reaches 24.85 dB over the frequency span of 8.2–12.4 GHz, which is 29.7% higher than the sum of CF/PDMS (19.53 dB) and Mn ₃ O ₄ /polytetrafluoroethylene/PDMS (0.27 dB). The excellent EMI SE stems from the synergism between CF and Mn ₃ O ₄ nanoparticles. In addition, after 1000 repeated bending cycles, the EMI SE of Mn ₃ O ₄ /CF/PDMS remains at 20.08 dB. Furthermore, the three‐layer Mn ₃ O ₄ /CF/PDMS composite (~1.08 mm) obtains an outstanding EMI SE of 63.87 dB, demonstrating an outstanding layered stacking effect.