Strontium ferrite nanoparticles were prepared by a coprecipitation method, and reduced graphene oxide/strontium ferrite/polyaniline (R-GO/SF/PANI) ternary nanocomposites were prepared by in situ polymerization method. The morphology, structure, and magnetic properties of the ternary nanocomposites were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), TEM, Raman, and VSM. The microwave-absorbing properties of the composites were measured by a vector network analyzer. The XRD patterns show the single phase of strontium hexaferrite without other intermediate phases. TEM photographs reveal that strontium ferrite nanoparticles are uniformly dispersed on the surfaces of R-GO sheets. The R-GO/SF/PANI nanocomposite exhibited the best absorption property with the optimum matching thickness of 1.5 mm in the frequency of 2–18 GHz. The value of the maximum RL was −45.00 dB at 16.08 GHz with the 5.48-GHz bandwidth. The excellent absorption properties of R-GO/SF/PANI nanocomposites indicated their great potential as microwave-absorbing materials.

Designing electromagnetic wave absorption (EMWA) materials with wide bandwidth, strong absorption, and light weight is still a great challenge for practical applications. Herein, the novel nitrogen doped carbon (NDC)/MoS₂ composite with rationally designed composition and structure was developed. The NDC particles were introduced into MoS₂ nanosheets through the calcination of ZIF-8 precursor and consequent hydrothermal process. A series of characterizations were carried out to investigate the physical properties of the as-prepared nanocomposites. The NDC particles exhibited the shape of rhombic dodecahedron with the size of about 500 nm, which were decorated on flower-shaped MoS₂ with the size of about 3 µm. With the increasing NDC content, the absorbing properties of NDC/MoS₂ composites increased firstly and then decreased. The features of NDC/MoS₂ composite including interconnected porous structure, nitrogen dopant, and appropriate electrical conductivity gave rise to the polarization, multiple reflection, multiple scattering, and impedance matching, resulting in the outstanding EMWA performance. With a filler loading ratio of 30 wt.%, the optimized EMWA property can be achieved when the mass ratio of NDC to MoS₂ was adjusted to be 1:1. At a coating thickness of 3.0 mm, the effective EMWA bandwidth (< −10 dB) reached 6.08 GHz (8.56–14.64 GHz). These satisfactory achievements provide a way for the reasonable design of high-performance EMWA and new ideas for future research on wideband EMWA.