Facile synthesis of NiS₂@MoS₂ core-shell nanospheres for effective enhancement in microwave absorption

Core-shell structured NiS₂@MoS₂ nanospheres have been successfully fabricated via a facile hydrothermal method. The structure and morphology of the nanospheres were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results indicated that this unique core-shell structure was beneficial to high-performance microwave absorption. A possible absorption mechanism was explained in detail. As an absorber, nanocomposites with a filler loading of 20 wt% exhibited enhanced microwave absorption properties due to characteristic impedance matching, synergistic effects, dipole and interface polarization, multiple reflections and quarter-wavelength matching. The minimum reflection loss can reach -41.05 dB at 12.08 GHz, and the absorption bandwidth exceeding -10 dB is 4.4 GHz with a thickness of 2.2 mm.