Ultralight melamine foam derived metal nanoparticles encapsulated CNTs/porous carbon composite for electromagnetic absorption

Three-dimensional (3D) porous carbon materials have emerged as potential microwave absorption candidates due to their unique advantages of high specific surface area and high porosity. However, much less attention has been paid to enhance the performance by designing microstructures. In this work, metal nanoparticles encapsulated carbon nanotubes/carbonized melamine foam composites were successfully synthesized by a simple chemical and pyrolysis method. The microstructure and microwave absorption properties are investigated, and the magnetic/dielectric loss mechanism is studied furtherly. During the pyrolysis process, metal nanoparticles encapsulated carbon nanotubes in-situ growth on 3D porous carbon derived from melamine foam. The metal component and CNTs morphology could be regulated by changing the precursor concentration and that further tuning the absorption performance. Ascribed to multiple interface reflections, dielectric/magnetic loss, multiple polarization behavior and improved impedance matching, the CNTs/CF-3:0 composite achieves a strong reflection loss (− 75.4 dB at 5.2 GHz) and ultra-wide response bandwidth (4.1–18.0 GHz with RL value over − 10 dB). Such a 3D network framework realizes the low density. These results may generate interest and inspiration for the elaborate design and synthesis of submicron-scale structures of 3D porous carbon-based absorbing materials.