Polyaniline-Functionalized Nanosized Cobalt Ferrite-Decorated MoS₂ Composites for Broadband Electromagnetic Wave Absorption

This study presents the synthesis of polyaniline (PANI)-coated cobalt ferrite-decorated molybdenum disulfide (MoS₂@CoFe₂O₄); a composite architecture engineered to combine unique morphological, magnetic, and dielectric properties for the electromagnetic wave/radar absorption applications. MoS₂ and CoFe₂O₄ were produced separately using a one-step hydrothermal process. Then, the CoFe₂O₄ nanoparticles were integrated into the flower-like MoS₂ nanosheets using the sonication method. Finally, PANI was synthesized through in situ polymerization of aniline on the surface of MoS₂@CoFe₂O₄ to create the final design as well as to boost the dielectric performance. Structural analysis confirmed the existence of the 2H phase and a minor trace of the 1T phase in MoS₂, while CoFe₂O₄ displayed a cubic structure without any detectable impurities. Scanning electron microscopy verified the successful distribution of CoFe₂O₄ particles within the MoS₂ nanosheets, aligning with the design’s intended configuration. The electromagnetic wave (EMW) characteristics of the composites were analyzed by using a vector network analyzer. The MoS₂@CoFe₂O₄ demonstrated a broad effective absorption bandwidth, spanning from the X-band to the Ku-band with a minimum matching thickness of just 2 mm. The reflection loss minimum value (RL_min) reached −22.82 dB at 8.96 GHz, corresponding to a 99.47% absorption of the incident EMWs. The addition of PANI at 50% by weight further increased the RL_min value to approximately 99.999% absorption (−50 dB), indicating enhanced impedance matching and absorption efficiency.