Two-dimensional MXene materials have garnered widespread attention in the fields of electromagnetic wave (EMW) absorption, owing to their exceptional electrical conductivity, structural versatility, and inherent hydrophilicity. In this study, we design a mild exfoliation strategy, specifically controlling the ultrasonic temperature and duration to exfoliate middle multi-layer Ti₃C₂T_x MXene materials through cavitation effect and water molecules intercalation, obtaining Ti₃C₂T_x MXene materials with varying layer thicknesses, which are expected to serve as excellent EMW absorption materials. The dipolar relaxation polarization provided by surface terminal groups (−F, −OH, −O) and polar water molecule (H₂O), the interface polarization formed between layers, and the transition from interface polarization to conduction loss driven by the nanosheet thickness and size, all contribute to the exceptional EMW properties. Finally, the 25 °C-3 h sample reaches a minimum reflection loss (RL_min) of −41.01 dB, corresponding to an effective absorption bandwidth (EAB) of 4.64 GHz. The radar cross section (RCS) simulation validates the feasibility of the material in practical scenarios, giving the values of RCS_min and RCS_ave as 0.16 and –28.80 dB·m². Simulations conducted on a JF-17v1 fighter result in an effective radar stealth performance. This work proposes a mild exfoliation strategy for Ti₃C₂T_x MXene materials and develops ultra-light aerogels with excellent wave-absorbing properties and radar stealth effects, aiming to expand their potential for future practical applications.

Biomass-derived carbon aerogels have emerged as promising electromagnetic protection materials due to their ultralight, porous, and eco-friendly properties, yet achieving high performance with environmental durability remains challenging. Employing an electromagnetic synergistic strategy, this work successfully fabricated a lotus seedpod-inspired carbon-based aerogel composite (SPCA@Co) using shaddock peel biomass, where magnetic Co components were introduced via zeolitic imidazolate framework (ZIF)-67. The material’s natural hierarchical porous structure and Co nanoparticle-anchored heterogeneous interfaces optimize impedance matching by regulating conductivity, polarization, and magnetic loss, yielding exceptional electromagnetic protection performance: −52.5 dB minimum reflection loss (RL_min) of 4.52 GHz effective absorption bandwidth (EAB) at 1.4 mm thickness, and 76 dB shielding efficiency. Simultaneously, SPCA@Co exhibits multifunctionality in complex environments, integrating thermal insulation, hydrophobicity, mechanical robustness, and stability under acid rain/weathering, with adaptability validated by radar cross-section simulations. This work provides a sustainable strategy for designing high-performance, multifunctional electromagnetic protections using biomass resources.