Construction of Lignin-Derived N-Doped Carbon Nanotubes Embedded with Co Single Atoms and Nanoparticles for Electromagnetic Wave Absorption

Electromagnetic wave absorption (EMA) materials have attracted considerable attention owing to their potential applications in electromagnetic stealth. Herein, lignin-derived N-doped carbon nanotube-based materials (Co–N–C/CNT–X) containing cobalt single atoms and nanoparticles were constructed to form a multiscale heterostructure with enhanced electromagnetic attenuation capability. The porous architecture and abundant defect sites in Co–N–C/CNT–E1 promote multiple reflection and dipole polarization, while cobalt species provide magnetic loss, thereby enhancing electromagnetic wave attenuation. As a result, Co–N–C/CNT–E1 exhibits a minimum reflection loss (RLmin) of −60.91 dB at a matching thickness of 2.80 mm and an effective absorption bandwidth (EAB) of 5.62 GHz at 2.30 mm. Radar cross-section (RCS) simulations further demonstrate the excellent electromagnetic stealth capability of Co–N–C/CNT–X.