Construction of core–shell-structured Al2O3@ppy composites with high-performance electromagnetic wave absorption performance

In this study, flower sphere alumina was synthesized autonomously by hydrothermal and annealing processes. The in situ polymerization of polypyrrole on the surface of alumina at low temperatures based on the principle of component synergy has enabled the construction of a core–shell structure for Al 2 O 3 @ppy materials, resulting in excellent electromagnetic wave absorption properties. The effect of the addition of alumina and the morphology of the materials on the microwave absorption properties of Al 2 O 3 @ppy composites was also discussed. Various methods are used for the characterization of the material. The Al 2 O 3 @ppy composites were effective in matching thicknesses of 2.5 mm with a minimum reflection loss (RL) of − 65.8 dB at a frequency of 11.52 GHz and a maximum effective absorption bandwidth (EAB) of 5.6 GHz at a matched thickness of 2.0 mm. The results show that Al 2 O 3 @ppy composites can provide a reference for EMW absorber material research.