Enhanced Dielectric Loss via Six‐Coordinated Er Single Atoms on Porous Carbon Nanofibers for High‐Performance Electromagnetic Wave Absorption

Abstract The metal single‐atoms (M‐SAs) have shown enhanced electromagnetic wave absorption performances. However, the relationship between their coordination number with non‐metal atoms and their absorption property is still blurry. Here, erbium single‐atoms (Er‐SAs) coordinated with six nitrogen atoms on one‐dimensional (1D) nitrogen‐doped hollow carbon nanofibers (HCNF‐Er) are presented for high‐performance electromagnetic wave absorption. Density functional theory (DFT) calculations and experimental results reveal that the Er─N₆ configuration with D_{6 h} symmetry significantly enhances both conduction and polarization losses of the HCNF support, outperforming four‐coordinated M‐SAs with D_{4 h} symmetry. It is also found that the abundant porosity of the HCNF increases the surface area, optimizing impedance matching and enhancing the lightweight property of HCNF‐Er. Consequently, HCNF‐Er‐based film shows a wide effective absorption bandwidth (EAB) of 6.0 GHz. Furthermore, the film also exhibits excellent flexibility, thermal insulation, and mechanical strength. This study offers a comprehensive optimization of the coordination configurations of M‐SAs for electromagnetic wave absorption, emphasizing its potential for scalable applications.