Biomimetic coral-like Ni/N-doped carbon aerogel derived from self‑assembly of MOF and collagen protofibril for high-efficiency microwave attenuation and thermal management

• Magnetic Ni/N-doped carbon aerogel (NFCA) was prepared by self-assembly, freeze-drying, and pyrolysis carbonization using collagen protofibril and a Ni metal-organic framework (Ni-MOF). • The “biomimetic coral-like” structure, nitrogen atom doping, and 3D porous structure of NFCA endowed this carbon aerogel with outstanding impedance matching and electromagnetic wave attenuation performance. • The biomimetic coral-like NFCA exhibited excellent microwave attenuation, radar stealth, and thermal management capabilities. Developing high-efficiency and multifunctional electromagnetic wave absorbing (EMWA) materials is a notable challenge. Inspired by the biomorph of croal, this research introduces a straightforward and innovative approach to fabricating a biomimetic coral-like magnetic Ni/N-doped carbon aerogel (NFCA) with excellent electromagnetic wave (EMW) attenuation properties via water-induced Ni metal-organic framework (Ni-MOF) self-assembly using biomass collagen protofibril as spatial guidance, molecular template and nitrogen source. The outstanding absorption properties of NFCA are provided by defect-induced dipole polarization, the interfacial polarization provided by the yolk-shell Ni/C nanoparticles, and excellent impedance matching caused by the three-dimensional network structure and biomimetic coral-like micro-nano structure. By manipulating the mass ratio of Ni-MOF to collagen protofibril, the electromagnetic parameters can be tuned to obtain excellent EMW attenuation capability. Electromagnetic parameter analysis shows that the biomimetic coral-like NFCA exhibits a minimum reflection loss (RL min ) of −64.40 dB (t = 2.02 mm, f = 11.60 GHz) and an effective absorption bandwidth (EAB) of 4.8 GHz (t = 1.82 mm, 11.54–16.34 GHz). Furthermore, NFCA demonstrates outstanding radar and infrared stealth capabilities as well as effective thermal management. This work demonstrates the excellent prospects of high-performance, easily manufactured, and multifunctional biomimetic coral-like carbon aerogels for applications in electromagnetic protection, electronic devices, and aerospace technologies.