Facile synthesis of a 2D multilayer core–shell MnO2@LDH@MMT composite with a nanoflower shape for electromagnetic wave absorption

Manganese dioxide@NiFe layered double hydroxide@montmorillonite (MNFM) with a nanoflower-like two-dimensional layered core–shell construction has been successfully synthesized by a two-step hydrothermal method. The structural and compositional influences on its electromagnetic wave (EW) absorption characteristics were discussed. MNFM with 8 mm thickness displayed excellent performance, which showed a minimum reflection loss (RLmin) of −21.8 dB at 15.4 GHz and an effective absorption bandwidth of 4.6 GHz. Meanwhile, RLmin was −13.5 dB at 13. 5 GHz when the thickness was 2.8 mm, and the effective absorption bandwidth was 3.31 GHz. The improved EW absorption performance may be attributed to the multilayer core–shell heterostructure leading to multipole relaxations and the ternary composite with excellent impedance matching. Hence, this work introduces a new idea for constructing core–shell clay-based nanocomposites, which are a promising material for EW absorption.