Biomass carbon-MXene based SiBCOFe ceramic aerogels with tailored interfacial polarization and impedance matching

2D MXene synergistically combines with biochar fibers to construct a porous 3D conductive network. • Ceramic aerogels possess superior microwave absorption capabilities coupled with structural stability. • A synergistic attenuation mechanism dielectric loss, magnetic loss, polarization, as well as multiple refraction and scattering is achieved. • An ultra-strong reflection loss of −60.1 dB is achieved at a thickness of 2.9 mm. Developing efficient electromagnetic wave absorbing materials capable of adapting to complex environments is of significant importance for advanced radar and electronic systems. Here, highly conductive MXene nanosheets are introduced into the biomass macromolecule bacterial cellulose (BC), and a BC/MXene (BM) hybrid scaffold with a honeycomb-like structure was prepared via directional freeze-drying. Subsequently, the SiBCOFe precursor was combined with the BM scaffold using a liquid-phase infiltration method, yielding BM/SiBCOFe ceramic aerogels. The results show that the conductive network formed by pyrolyzed BC-derived biomass carbon synergistically with MXene enhances the dielectric loss capability of the aerogel. Meanwhile, the heterostructures in situ generated on the surface of the BM from the precursor effectively improve the interfacial polarization effect and mechanical properties of the aerogel. Fe doping not only enhances magnetic loss but also optimizes impedance matching, ultimately achieving dual improvement in microstructure design and electromagnetic wave absorption performance. The BM/SiBCOFe ceramic aerogels exhibits excellent electromagnetic wave absorption performance: at a matching thickness of only 2.9 mm, the minimum reflection loss ( RL min ) reaches −60.1 dB, with an effective absorption bandwidth (EAB) of 4.6 GHz. The aerogel also exhibits excellent thermal and structural stability, making it an efficient electromagnetic wave absorbing material suitable for extreme environments. Download: Download high-res image (317KB) Download: Download full-size image