Construction of a hydrangea-like core–shell structured GM@NiFe-LDH@PANI composite for efficient electromagnetic wave absorption

Abstract

In answer to the need for materials that absorb electromagnetic waves with great efficiency, this study reports the design and synthesis of a core–shell structured GM@NiFe-LDH@PANI composite. The material exhibits outstanding electromagnetic wave (EMW) absorption performance through multi-component synergy and multi-mechanism coupling. XRD and XPS analyses confirmed the material’s crystalline structure and chemical composition, while SEM images revealed the core–shell morphology, showing NiFe-LDH nanosheets uniformly anchored on glass microspheres (GM) surfaces, forming a hydrangea-like structure. Subsequent incorporation of polyaniline (PANI) further increased the heterojunction interface. Electromagnetic property measurements demonstrated that GNP-2 achieved optimal impedance matching at a thickness of 1.71 mm, resulting in a strong reflection loss of −52.86 dB and an effective absorption bandwidth of 4.72 GHz. The hydrangea-like NiFe-LDH structure enhances magnetic loss and promotes scattering and reflection through its porous framework, intensifying interfacial polarization effects. The conductive PANI shell, with its exposed active sites, facilitates EMW absorption through dipole polarization and conductive loss mechanisms. This core–shell porous design synergistically optimizes dielectric and magnetic losses. This composite material demonstrates considerable potential for electromagnetic compatibility applications in radar stealth, modern communication systems, and renewable energy devices.