Hierarchical Composite CoFe-K/GC@MnO2@MXene for Excellent Electromagnetic Wave Absorption

Electromagnetic wave absorption (EMWA) materials with qualities such as low cost, thin thickness, and high efficiency are of tremendous value in addressing the challenges posed by EMW pollution. Herein, we have successfully synthesized a nanoflower-like composite from the Prussian blue analog KCoFe(CN)6 through a combination of hydrothermal and post-annealing methods. Subsequently, we prepared the hierarchical composite CoFe-K/GC@MnO2@MXene (CMM) by electrostatic self-assembly with few-layered Ti3C2Tx nanosheets. Their chemical compositions, microstructures, and EMWA performances were thoroughly investigated. The CMM composite demonstrated outstanding EMWA performance with an impressive minimum reflection loss (RLmin) value of -53.0 dB at 1.68 mm and an effective absorption bandwidth (EAB) value of 4.0 GHz with an ultrathinmatching thickness of only 1.55 mm. The exceptional EMWA performance of CMM can be attributed to the increased conductive loss, enhanced interfacial polarization, and optimized impedance matching. Simulated radar cross-section (RCS) plots confirm the outstanding RSC reduction achieved by the CMM absorber coating. Furthermore, the EAB can be extended to 12.12 GHz by designing a macro 3D quadrangular frustum pyramid structural model for the absorber. The practical application potential of CMM was also enhanced by its good heat dissipation capability, which was demonstrated in real-time using an infrared thermal imager. This work provides a novel insight into developing efficient and multifunctional EMWA materials for practical applications.