High‐Entropy Strategy‐Driven Lattice Distortion and Electronic Rearrangement in MOF‐Derived HEA/NC Composites for Balanced Electromagnetic Response and Superior Microwave Attenuation

ABSTRACT The increasing electromagnetic pollution urgently requires the development of high‐performance and multi‐functional electromagnetic wave absorbers (EMA). High‐entropy alloys (HEA) have attracted attention in the field of EMA for their exceptional synergistic effects and tunable electronic structures. However, their high density and susceptibility to phase separation during conventional heat treatment severely hinder their effective composite with carbon materials and further application. Herein, a series of homogeneous and stable FeCoNiCuM (M = V, Cr, Mn)/NC composites were successfully synthesized by utilizing the spatial anchoring strategy provided by the MOF‐derived nitrogen‐doped carbon (NC) skeleton in conjunction with the fast‐moving pyrolysis method. By introducing V, Cr, and Mn to realize the high‐entropy strategy, the high configurational entropy and the mismatch of different atomic sizes induced a strong lattice distortion. Such distortions produce significant grain boundaries and distorted lattices, which greatly contribute to strong interfacial polarization and defect‐induced polarization. Benefiting from the high entropy effect, multi‐component synergy, and the HEA/carbon interface, which provides an excellent balance between dielectric and magnetic responses, the prepared composites exhibit outstanding EMW absorption characteristics. Among them, the FeCoNiCuMn/NC exhibits the RL _min of −56.25 dB. This work provides a novel perspective for developing new HEA‐based composites for high‐performance EMW absorption.