Wood-Derived Porous Carbon/Iron Oxide Nanoparticle Composites for Enhanced Electromagnetic Interference Shielding

Biomass materials have attracted attention in optimizing electromagnetic interference (EMI) shielding effectiveness (SE) ascribed to their high electric conductivities and reinforced polarization effects. Here, a wood-derived magnetic nanoparticle/porous carbon (PC) composite was fabricated via an in situ microwave-assisted pyrolysis approach. The unique anisotropic porous structures inherited from natural woods act as the three-dimensional conductive network and incorporate the magnetic iron oxide (γ-Fe2O3) nanoparticles homogeneously embedded within the matrixes that can further improve the electromagnetic absorption abilities. As a result, the Fe/PC composites demonstrate an optimized EMI SE of 44.80 dB at the regions of 8.2–12.4 GHz (X-band) with a thickness of 3 mm, while the normalized SE (EMI SE/volume) could reach 61.88 dB/cm3. Meanwhile, the multifunctional characteristics such as low density (0.271 g/cm3), hydrophobicity (water contact angle 132.2°), and mechanical stability (compression strength 11.1 MPa) can be achieved in Fe/PC composites, promising a great potential for future engineering applications.