Dielectric response of specific N configurations in N-doped carbon enables efficient electromagnetic wave absorption

N-doped carbon materials are promising electromagnetic wave (EMW) absorbers, yet the distinct roles of N configurations (Graphitic-N, Pyridinic-N, and Pyrrolic-N) in dielectric loss remain unclear. This work introduces a ligand-centered molecular design strategy using 2-methylimidazole and 4-dimethylaminopyridine to precisely modulate N configurations. Systematic characterization reveals that 4-dimethylaminopyridine stabilizes Pyrrolic-N, increasing its content to 42.95% while reducing Graphitic-N to 9.57%, which introduces defects and enhanced polarization centers. Combining Debye relaxation theory and first-principles calculations, we quantitatively decouple dielectric contributions: Graphitic-N enhances conduction loss via improved carrier mobility, whereas Pyrrolic-N governs polarization loss. As a result, the Graphitic-N rich NC-M sample achieves a minimum reflection loss (RL) of −70.82 dB at 1.97 mm, while the Pyrrolic-N-rich NC-D sample extends the effective absorption bandwidth (EAB) to 5.9 GHz. This work establishes a clear structure-activity relationship, offering a rational pathway for designing configuration-controlled EMW absorbers. This work systematically elucidates the influence of different nitrogen configurations on the electromagnetic response mechanisms of materials by modulating the arrangement of nitrogen atoms, providing theoretical guidance and practical foundations for designing and constructing high-performance nitrogen-doped carbon-based materials for electromagnetic wave absorption. Download: Download high-res image (298KB) Download: Download full-size image