Multifunctional MoCx Hybrid Polyimide Aerogel with Modified Porous Defect Engineering for Highly Efficient Electromagnetic Wave Absorption

Traditional electromagnetic absorbing materials (EWAMs) are usually single functions and can easily affect their performance in diverse application scenarios. Effective integration of EWAMs into multiple function components is a valuable strategy to achieve maximum absorption and multifunction performance while maintaining their indispensable physical and chemical properties. In this work, the polyoxometalates (POMs) serving as "guests" are embedded within the Co-MOFs to construct 3d/4d-bimetallic based crystalline precursors of dielectric/magnetic synergistic system. The proper pyrolysis temperature induced the homogeneously distributed metallic Co and MoC_x hetero-units into carbon matrix with modified porous defect engineering to enhance electromagnetic wave (EW). Owing to the brilliant synergistic effect of polarization, magnetic loss, and impedance matching, the superior RL_min of -47.72 dB at 11.76 GHz at the thickness of 2.0 mm and a wide adequate absorption bandwidth (EAB) of 4.58 GHz (7.44-12.02 GHz) covered the whole X-band at the thickness of 2.5 mm for η-MoC/Co@NC-800 are observed. More importantly, the resulting MoC_x hybrid polyimide (MCP) aerogel exhibits desirable properties such as structural robustness, nonflammability, excellent thermal insulation, and self-cleaning capabilities that are comparable to those of commercially available products. This work offers inspiration and strategy for creating multipurpose microwave absorbers with intricate structural designs.