3D multifunctional porous pine carbon aerogels coupled with highly dispersed CoFe nanoparticles for robust electromagnetic wave response

Functional carbonaceous materials with controllable morphology, low apparent density, large surface area, and high porosity starting from natural precursors using environmentally friendly processes are an appealing topic in the electromagnetic wave (EMW) field. In this work, renewable pine woods with ordered pore channels are selected to load highly dispersed CoFe alloy nanoparticles formed by in-situ pyrolysis reaction between Fe₃O₄ nanospheres and ZIF-67 nanoparticles. The constructed three-dimensional (3D) porous CWA-CoFe-NC aerogel inherits the characteristics of highly dispersed small CoFe alloy nanoparticles, porous carbon aerogel with rectangular honeycomb-like structure, and abundant N heteroatoms. Therefore, CWA-CoFe-NC aerogel achieves an excellent EMW absorption performance with reflection loss (R_L) values of −61.6 and −58.2 dB at matching thicknesses of 3.7 and 1.2 mm, respectively. Benefiting from the reasonable design of the composite structure and composition, 3D porous aerogel also enables great potential for multifunctional applications. Particularly, good lightweight and mechanical properties are realized in the CWA-CoFe-NC aerogels due to their ordered pore channels and abundant rectangular pores. Furthermore, good flame retardant performance can ensure the serviceability of the target device in high/low-temperature environments. In addition, CWA-CoFe-NC aerogels show good thermal stability and thermal management characteristics. This work provides a novel and effective method for the preparation of lightweight, high-performance, and multifunctional EMW absorbers.