FeOx Nanoparticle/Coal Gasification Fine Slag Hybrids for Electromagnetic Wave Absorbers

Electromagnetic-wave (EMW) absorbers with strong reflection loss (RL) and a wide absorption frequency band under extremely thin thicknesses are highly desirable. Heterostructured multi-interface Fe3O4/FeO/Fe (FeOx) nanoparticle/coal gasification fine slag (CGFS) hybrids were successfully synthesized by coating highly graphitized CGFS with FeOx nanoparticles. The crystal structure, morphology, composition, magnetic performance, and electromagnetic (EM) parameters of FeOx/CGFS hybrids were tested using modern analysis and testing technology. Given their heterostructured multi-interface structural design, appropriate impedance matching, and synergy of dielectric and magnetic losses, the as-prepared FeOx/CGFS hybrids show adjustable and outstanding EMW absorption performances. The minimal RL (RLmin) of FeQ/CGFS hybrids is -61.6 dB at a thickness of 1.8 mm, and the widest effective absorption bandwidth (RL <= -10.0 dB) can cover 5.0 GHz (13.0-18.0 GHz) with a thickness of 1.7 mm. Furthermore, the results of the radar cross-section (RCS) simulation testify that FeOx/CGFS hybrids can effectively reduce EMW scattering in the X band by varying the thicknesses of the FeOx/CGFS hybrid coatings. These heterostructured multi-interface magnetic carbon-based EMW absorbers with high-performance EMW absorption and good reduction ability of the RCS can promote the resource utilization of CGFS.