Bamboo-derived fire-retardant porous carbon with excellent adjustable electromagnetic wave absorption performance

The increasing prevalence of electromagnetic pollution has necessitated the development of efficient electromagnetic wave-absorbing materials. This study focuses on the synthesis and characterization of magnetic bamboo-based composites (MBCs) derived from natural moso bamboo, aiming to enhance electromagnetic wave absorption performance through structural modulation and the introduction of magnetic components. Bamboo blocks were subjected to lignin removal and impregnated with iron acetylacetonate (Fe(acac)₃) precursor solutions, followed by in-situ pyrolysis to form Fe₃O₄-embedded carbon composites. The resulting materials were characterized using XRD, Raman spectroscopy, SEM, TEM, VSM, and XPS, revealing the successful integration of magnetic nanoparticles within the bamboo-derived carbon matrix. Electromagnetic wave absorption properties were evaluated in the 2–18 GHz frequency range, demonstrating that MBC-2, with an optimal Fe₃O₄ content, achieved a minimum reflection loss (RL) of − 58.4 dB at 1.5 mm thickness and an effective absorption bandwidth (EAB) of 6.13 GHz at 1.7 mm. The superior performance of MBC-2 is attributed to its balanced dielectric and magnetic losses, enhanced interfacial polarization, and optimized impedance matching. Additionally, MBC-2 exhibited excellent Joule heating performance, flame retardancy, and hydrophobic properties, highlighting its multifunctionality. This study provides a novel approach for designing high-performance biomass-based electromagnetic wave-absorbing materials, offering potential applications in military and civilian sectors for electromagnetic pollution mitigation.