Hierarchical FeCo@MoS₂ Nanoflowers with Strong Electromagnetic Wave Absorption and Broad Bandwidth

Advanced electromagnetic (EM) wave absorbing materials are technologically important with extensively increasing utilization of EM waves in the gigahertz range. Hierarchical structure containing FeCo nanoparticles composited with MoS2 nanoflowers was developed as an effective EM wave absorber. Large surface area and sufficient voids provided by the MoS2 nanoflowers enable uniformly dispersed FeCo nanoparticles with single domain size for enhanced permeability and natural resonance. Existence of the large amount of the FeCo/MoS2 interfaces also improves the dielectric loss. The composite not only exhibits satisfactory impedance matching over a wide frequency range but also provides synergistic effect between magnetic and dielectric loss for effective dissipation of the wave energy. Excellent wave absorption performance was achieved for the composite with a maximum reflection loss (RL) of −64.64 dB at 14.4 GHz and a broad effective absorption bandwidth (RL < −10 dB) of 7.2 GHz at a small thickness of 2 mm. Consequently, a novel type of high-performance wave absorber was developed, and insights for the design of advanced EM wave absorbers with strong absorption capacity and broad effective bandwidth were provided.