Synergistic Polarization Relaxation Loss in Multimetallic Hierarchical Hybridization and Preferred Orientation Strategies for Electromagnetic Wave Absorption

Precise modulation of hierarchical heterostructures in hybrid materials is essential for optimizing electromagnetic wave (EMW) attenuation. This study presents a multi‐metal ion exchange strategy to construct hierarchical heterostructures in Co/Sn/Se nanocomposites by integrating electrospun‐derived nanofibers with metal–organic frameworks (MOFs). The resulting composites exhibit hierarchical heterostructures at the atomic, phase, and interface levels, and incorporate a large number of polarization centers, thereby enhancing polarization relaxation loss. Consequently, the optimized Co/Sn/Se hybrid achieves a remarkable minimum reflection loss (RL min ) of −50.81 dB and an effective absorption bandwidth (EAB) of 5.84 GHz. Dielectric and electrochemical analyses further elucidate the underlying charge transfer behavior and energy dissipation pathways. Density functional theory (DFT) calculations reveal that multi‐metal hybridization and selenium incorporation induce charge redistribution, facilitating the formation of a built‐in electric field (BIEF) to drive strong interfacial polarization. This study provides new insights into the hybridization design of high‐performance EMW absorbers.