Controllable Fabrication of <scp>MnCo₂O₄</scp>@Polypyrrole@<scp>MXene</scp> Ternary Composites for Electromagnetic Wave Absorption

ABSTRACT Nowadays, excessive microwave radiation has become one of the urgent factors affecting human health. To solve the negative effects, electromagnetic wave‐absorbing materials have gradually become indispensable applications. Here, MnCo 2 O 4 @polypyrrole (PPy)@MXene (MPM) ternary composites are successfully synthesized by the combination of hydrothermal synthesis, high‐temperature sintering, in situ polymerization method, and low‐temperature freeze drying. The synergistic effect between dielectric loss and magnetic loss of MnCo 2 O 4 , Ppy, and MXene is studied in detail, showing the prepared composites have excellent absorption properties. MPM‐1 exhibits minimum reflection loss (RL min ) of −62.99 dB at 16.04 GHz under the ultra‐thin thickness (1.21 mm, 50 wt%), and the effective absorption bandwidth (EAB) is 3.94 GHz (13.44–17.38 GHz) at 1.28 mm (50 wt%). The prepared MPM composites have ultra‐thin thickness, wide absorption bandwidth, and excellent microwave absorption properties, which are ascribed to the combination of dielectric loss, magnetic loss, and multiple reflection and scattering effects of core–shell structure. These composites can be used as a significant electromagnetic wave absorbing material, and provide a new research idea for the application of ternary composite materials in electromagnetic wave absorbing materials.