Synergistic sp-C/sp-N Anchoring of Metal Single Atoms on Graphdiyne for Enhanced Microwave Absorption

The metal single-atom doping strategy was systematically applied to graphdiyne (GDY), an emerging two-dimensional carbon material, and a series of M-N-GDY single-atom microwave absorbers were successfully fabricated for the first time. Combining X-ray absorption fine structure and density functional theory calculations, the influence of the central atom coordination structure (FeN₂C₂, FeC₄) on the overall electronic properties was elucidated. The optimal sample Fe-N-GDY achieved an effective absorption bandwidth of 5.98 GHz at a matched thickness of 2.0 mm, with a minimum reflection loss of -51.2 dB.