Flower-Like CuS/MoS2Nanoflake Composites as Heterojunctions for Microwave Absorption

Molybdenum disulfide (MoS2), a two-dimensional transition metal disulfide (TMD), is of great concern in microwave absorption (MA). Nevertheless, pure MoS2 has limitations in realizing outstanding MA performance owing to its lower conductivity and smaller dielectric constant. To address this, compounding it with highly conductive CuS not only improves its conductivity and impedance-matching properties but also increases the interfacial polarization within the material and enhances the MA properties of the material. In this study, flower-like heterostructured CuS/MoS2 nanoflake composites were prepared using the hydrothermal method. The characterization of the morphology and properties reveals the existence of a considerable number of heterogeneous interfaces in the composites, resulting in increased dielectric loss capability. By adjusting the ratio with CuS and MoS2, the CuS/MoS2-30 composite achieved an effective absorption bandwidth (EAB) of 6.4 GHz (from 11.6 to 18 GHz) and a minimum reflection loss (RLmin) of −57.89 dB. Meanwhile, the CuS/MoS2-50 composite with a matched thickness of 2.17 mm and an EAB of 6 GHz achieved the RLmin value of −63.09 dB. These outstanding properties are based on the transition metal sulfide heterojunction formation of microwave absorbents; without coupling with magnetic materials, it shows excellent synergistic loss through dielectric–dielectric interaction. It is demonstrated that the flower-like heterojunction CuS/MoS2 nanoflake composites are potentially ideal microwave absorption materials.