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 (RL_min) 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.