Controllable Architecture of ZnO/FeNi Composites Derived from Trimetallic ZnFeNi Layered Double Hydroxides for High‐Performance Electromagnetic Wave Absorbers

The optimization design of micro‐structure and composition is an important strategy to obtain high‐performance metal‐based electromagnetic (EM) wave absorption materials. In this work, ZnO/FeNi composites derived from ZnFeNi layered double hydroxides are prepared by a one‐step hydrothermal method and subsequent pyrolysis process, and can be employed as an effective alternative for high‐performance EM wave absorber. A series of ZnO/FeNi composites with different structures are obtained by varying the molar ratios of Zn 2+ /Fe 3+ /Ni 2+ , and the ZnO/FeNi composites with a Zn 2+ /Fe 3+ /Ni 2+ molar ratio of 6:1:3 show a hierarchical flower‐like structure. Owing to the strong synergistic loss mechanism of dielectric‐magnetic components and favorable structural features, this hierarchical flower‐like ZnO/FeNi sample supplies the optimal EM wave absorption performance with the highest reflection loss of −52.08 dB and the widest effective absorption bandwidth of 6.56 GHz. The EM simulation further demonstrates that impedance matching plays a determining role in EM wave absorption performance. This work provides a new way for the fabrication of a high‐performance metal‐based EM wave absorber.