One-Pot Hydrothermal Synthesis of Core-Shell MnS@MoS2 Heterojunction for Enhanced Microwave Absorption

As a typical 2D transition metal dichalcogenide (TMD), molybdenum disulfide (MoS2) has received widespread attention in the field of microwave absorption (MA). However, pure MoS2 still has disadvantages in achieving the target of excellent MA performance due to its weak ability in electromagnetic wave (EMW) energy attenuation, in addition to the complicated preparation process of MoS2-based composites. It is highly significant to develop functionalized MoS2 with a low-cost, high-efficiency, and facile preparation process. Herein, a novel core-shell MnS@MoS2 composite with spherical flower-like structure is developed by a one-pot hydrothermal method. The morphological and performance characterization demonstrates the existence of numerous heterogeneous interfaces, which dramatically enhance the dielectric loss capability of the composites. By adjusting the ratio of Mo4+ and Mn2+, the minimum reflection loss (RLmin) of MnS@MoS2-40 composite reaches -65.19 dB and the effective absorption bandwidth (EAB) reaches 6.72 GHz. At the same time, MnS@MoS2-60 composite can achieve the RLmin value of -53.58 dB and an EAB of up to 6.16 GHz (from 11.44 to 17.6 GHz) at a thickness of only 1.78 mm. These outstanding performances are based on microwave absorbers formed by transition metal sulfide heterojunctions, pioneering the first combination of alpha-MnS and MoS2 for MA applications.