Fe-MOF Modified Bubble Coral-Like Carbon Nanofibers for Ultrathin Broadband Microwave Absorption

Driven by the rapid development of microelectronics and aerospace engineering, lightweight, ultrathin, broadband microwave absorption (MA) materials are urgently required for advanced electromagnetic protection and stealth technologies. Conventional ceramic-derived MA absorbers face inherent bottlenecks of incompatible impedance matching and insufficient attenuation efficiency, severely restricting their application in miniaturized aerospace and electronic systems. A novel bubble coral-like Fe-MOF modified carbonaceous nanofiber composite (BF@CNFs) is fabricated via electrospinning, thermal curing, and high-temperature carbonization, with its microstructure precisely tailored by optimizing polyacrylonitrile/phenolic resin ratio and carbonization heating rate. The optimized BF@CNF-2 delivers a minimum reflection loss of −36.2 dB at 1.3 mm thickness, with an effective absorption bandwidth nearly covering the entire Ku-band (12.0–18.0 GHz). This outstanding performance stems from the synergistic effect of conductive carbon nanofiber scaffolds and Fe-MOF-derived magnetic phases. The work provides a scalable, ceramic-compatible strategy for high-performance MA materials, addressing long-standing technical challenges, with promising prospects in aerospace stealth and electromagnetic shielding.