Gradient pyrolysis-derived multiphase heterogeneous interfaces for enhanced electromagnetic wave absorption

Interfacial polarization loss is crucial in dielectric loss for electromagnetic wave absorption. Constructing abundant heterogeneous interfaces, alongside leveraging inherent dielectric behaviors, plays a vital role in attenuating electromagnetic waves. However, traditional methods often struggle to achieve precise construction of these interfaces. In this work, a metal-organic framework (MOF) precursor is utilized with gradient pyrolysis engineering to fabricate multiphase heterogeneous interfaces. Through in situ synthesis, a coral-like ZnFe₂O₄/Co _x S _y /C (ZCC) composite is successfully prepared. The robust interactions between the different sulfides, along with those between the sulfides and the carbon matrix, facilitated the fine-tuning of dielectric properties, electrical conductivity, and electromagnetic wave absorption characteristics. ZCC-700, in particular, attain a reflection loss as low as −66.27 dB, couple with an effective absorption bandwidth (EAB) spanning 5.01 GHz. While ZCC-800 demonstrates a reflection loss of −58.28 dB and an EAB of 5.17 GHz, ensuring efficient absorption across the S, C, and Ku frequency bands. Additionally, radar cross-section simulations at 4.8 GHz and 5.2 GHz demonstrate the radar stealth potential of ZCC-700. This study employs a gradient pyrolysis heterogenization process to regulate dielectric behavior dominated by multiphase heterogeneous interfaces and combined dielectric-magnetic coupling synergy, offering a novel strategy to optimize electromagnetic wave absorption performance.