N-Doped Synergistic Co Nanoparticles-Graphdiyne Heterostructure Enhances Microwave Absorption Performance of Two-Dimensional Materials

Abstract Graphdiyne (GDY), an emerging two-dimensional carbon material, requires the construction of composite structures/components to synergize multiple loss mechanisms for its further advancement in microwave absorption. This study employed a multicomponent complementary strategy to design and fabricate a N-doped GDY composite loaded with Co particles (Co/N-GDY) as a microwave absorbing material. By coupling the advantages of the sp/sp2 hybridized carbon network of GDY, N atom doping, and Co nanoparticles, precise regulation of the dielectric properties and impedance matching characteristics of GDY was achieved. Mechanistic investigations based on first-principles calculations reveal that revealed that N-doping not only enhanced dipole polarization but also effectively mitigated potential adverse electrical effects induced by the Co particles. Concurrently, the Co nanoparticles induced strong interfacial polarization by creating abundant heterogeneous interfaces, thereby compensating for the loss limitations associated with single N-doping. The resulting Co/N-GDY composite exhibited exceptional microwave absorption performance within the 2–18 GHz frequency band. At a minimal matching thickness of merely 1.8 mm, the material achieved a wide effective absorption bandwidth (EAB) of 5.08 GHz and a minimum reflection loss (RLmin) of −56.91 dB. This work offers a novel strategy for designing high-performance microwave absorption materials and is expected to promote the application of GDY in electromagnetic functional materials.