Hybridization, microcurrent networks, and multi-interface effects in 2D/2D/2D Bi₂MoO₆/BiS_x@NC/MoS₂ heterostructure for electromagnetic wave absorption

Two-dimensional (2D) materials, especially their heterostructures, have garnered significant attention in the field of electromagnetic wave (EMW) absorption, owing to their high specific surface area and the capability to extend EMW propagation paths. However, conventional 2D/2D heterostructures frequently encounter challenges such as limited interfacial diversity, poor impedance matching, and insufficient synergistic effects of loss mechanisms, which collectively constrain further advancement in EMW absorption. To address these limitations, we have engineered a novel 2D/2D/2D hierarchical heterostructure, denoted as Bi₂MoO₆/BiS_x@nitrogen-doped carbon/MoS₂ (Bi₂MoO₆/BiS_x@NC/MoS₂). The distinctive architecture of this heterostructure features a rational layered configuration: the outer MoS₂ layer functions as an “impedance matching layer” to promote EMW entry; the intermediate NC layer serves as a polarization-induced “trapping layer” to suppress secondary reflection; and the inner Bi₂MoO₆/BiS_x layer acts as the “absorption layer” responsible for core energy dissipation. This deliberate multi-layer design facilitates interconnected microcurrent networks, induces multi-interface polarization, and harnesses multi-component hybridization effects, thereby achieving optimized impedance matching and synergistic dielectric/magnetic losses. Consequently, the designed heterostructure inherits exceptional EMW absorption performance, with an ultra-strong reflection loss (R_L) of −63.57 dB and a broad effective absorption bandwidth (EAB) of 3.55 GHz at a matching thickness of only 2.85 mm. This work provides valuable insights into the structural design of advanced 2D heterostructures and offers a functional unit analysis perspective for developing high-performance EMW absorbers.