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

Abstract

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.