Designing “Sphere/Network” Hierarchical Dielectric Loss Structure for Efficient Electromagnetic Wave Absorption

ABSTRACT Electromagnetic wave absorption materials require high dielectric loss and excellent impedance matching performance. However, current conventional biomass‐derived electromagnetic wave absorption materials are still limited by low electrical conductivity and a single structure. In this work, a “sphere/network” hierarchical attenuation electromagnetic wave absorption material, which combines weakly conductive biomass‐derived carbon spheres and highly conductive cantaloupe‐like textured polypyrrole, was synthesized using Fe 3+ and methyl orange as template‐directing agents. Under the guiding effect of methyl orange, polypyrrole does not undergo disordered agglomeration on the surface of carbon spheres; instead, tubular polypyrrole grows orderly along the sphere surface and assembles to form a continuous conductive network. Conduction loss, dipole polarization, and interfacial polarization loss—acting as cooperative loss mechanisms—enable OJ‐MO‐PPy‐2.5 to achieve broadband effective absorption, with an effective absorption bandwidth of 7.2 GHz and a minimum reflection loss of −48.82 dB. Meanwhile, computer simulation technology (CST) simulation results indicate that after coating OJ‐MO‐PPy‐2.5, the reflection intensity of the electromagnetic wave is reduced by approximately three times when the wave is incident normally. The successful fabrication of OJ‐MO‐PPy furnishes novel insights for biomass‐derived electromagnetic wave absorption materials with broadband absorption capabilities.