Heterojunction Engineering of MOFs and MXene on Melamine Foam Toward High-Performance Microwave Absorption and Flame Retardancy

Developing lightweight multifunctional materials with both strong electromagnetic microwave (EMW) absorption and robust flame retardancy is essential for addressing electromagnetic interference and fire risks in modern electronics. In this work, ZIF-67@NH₂-MIL-88B(Fe)/MXene-modified melamine foam (ZIF@MIL/MXene/MF) composite aerogels were constructed to achieve synergistic dielectric loss and magnetic loss mechanisms. The optimized ZIF@MIL/MXene/MF-5 exhibited outstanding EMW absorption, with a minimum reflection loss (RL_min) of −55.82 dB and an effective absorption bandwidth of 4.52 GHz, along with a radar cross-section reduction of 15.27 dB·m². The superior absorption originates from conductive network pathways, abundant heterogeneous interfaces for polarization loss, dipole relaxation, and magnetic loss from CoFe alloy nanoparticles, combined with excellent impedance matching. Additionally, the composite demonstrated excellent fire safety, with peak heat release rate, total heat release, and total smoke production reduced by 34.0%, 64.6%, and 87.9%, respectively, owing to catalytic graphitization and the formation of a compact char barrier. These results demonstrate an effective strategy for designing lightweight multifunctional aerogels for next-generation electromagnetic protection and fire-safe engineering applications.