Controllable preparation of 3D porous Co/Mo2C/C aerogels: Synergizing multifunctionality with efficient microwave absorption performance

Biomass-derived carbon-based composites are widely recognized as prospective candidates for high-performance microwave absorbing materials (MAMs), leveraging synergistic electromagnetic loss mechanisms and charming structural effects. However, uneven distribution of heterogeneous components and complex preparation processes limit performance elevation and large-scale application. Herein, a novel “one-step gelation coupled with simultaneous pyrolysis” strategy is proposed to successfully prepare 3D porous Co/Mo 2 C/C aerogels using lotus root powder as carbon source. This strategy achieves in-situ reduction and carbonization of Co and Mo species, resulting in uniformly dispersed nanoparticles within carbon matrix. Mo 2 C nanoparticles serve as structural scaffolds to inhibit carbon framework collapse during pyrolysis, thus preserving 3D porous architecture. Sufficient heterogeneous interfaces among Mo 2 C, carbon, and Co notably enhance dielectric loss. Additionally, the introduced Co nanoparticles contribute magnetic loss and synergize with the porous structure to optimize impedance matching. By regulating the content of Mo 2 C, the optimized Co/Mo 2 C/C-2 demonstrates satisfactory microwave absorption performance. Its minimum reflection loss ( RL ) and effective absorption bandwidth ( EAB 10 ) can reach up to −64.5 dB and 4.8 GHz with a thickness of only 1.4 mm, along with a broad integrated EAB 10 of 14.7 GHz within a thickness range of 1.0 mm to 5.0 mm. Furthermore, the composite inherits bio-carbon's lightweight trait and exhibits decent hydrophobicity and thermal insulation, endowing it with adaptability and broad application potential in complex service environments. These merits make Co/Mo 2 C/C aerogels highly competitive for advanced electromagnetic protection and stealth applications in harsh and complex service environments.