Flower-like CuS/γ-Fe2O3 van der Waals heterostructures with high-efficient electromagnetic wave absorption

The escalating electromagnetic (EM) pollution issues and the demand to elevate military stealth technology make it imperative to develop cost-effective and high-performance electromagnetic wave (EMW) absorbing materials. In this paper, the flower-like CuS/γ-Fe2O3 van der Waals (vdW) heterostructures have been synthesized via a facile two-step solvothermal approach. The flower-like CuS skeleton increases the attenuation path of EMW while reducing the material density. Different contents of γ-Fe2O3 nanoparticles anchor between the flower-like CuS nanosheets to constitute a heterogeneous structure, which enables dielectric and magnetic loss synergistically to optimize impedance matching and remarkably improve the EMW absorption performance. The minimum reflection loss (RLmin) is −49.36 dB with a thickness of only 1.6 mm and the effective absorption bandwidth (EAB) reaches 4.64 GHz (13.36–18 GHz). By adjusting the thickness of the absorber, the EAB can cover 96% of the GHz band. Notably, the superior absorption of −61.53 dB at middle frequency band can be obtained by adjusting the amount of Fe2O3 addition. In this study, the adjustment of EM parameters and the optimization of impedance matching have been achieved by constructing a novel vdW heterogeneous structure, which provides fresh ideas and references for the design of high-performance EMW absorbing materials.