Excellent electromagnetic wave absorption properties of the ternary composite ZnFe₂O₄@PANI-rGO optimized by introducing covalent bonds

The ternary composite material ZnFe₂O₄@PANI-rGO with a core-shell structure and excellent electromagnetic absorption properties has been prepared by covalently modifying reducing graphene oxide with the binary magnetic material ZnFe₂O₄@PANI. The ternary composite material ZnFe₂O₄@PANI/rGO forms a " CO–NH ″ covalent bond between ZnFe₂O₄@PANI and rGO through hydrothermal routes and mechanical stirring. By comparing the two types of the connection method covalent and non-covalent bonds, it was surprised to find that formed by covalently connecting the binary ZnFe₂O₄@PANI material and rGO (C-ZPr) to obtain extremely excellent electromagnetic absorption performance. By adjusting the thickness from 1 mm to 4 mm, when the filler ratio is 20%, the minimum reflection loss (R_Lmin) at 2.1 mm was as low as −49.99 dB at 17.28 GHz and the effective absorption bandwidth (R_L < 10 dB) was almost 4.32 GHz. The introduction of covalent bonds becomes a bridge connecting magnetic materials and dielectric materials, adjusting electromagnetic parameters, enhancing reflection loss, and achieving impedance matching and improved electromagnetic absorbing performance. This preparation method is expected to provide new ideas for the preparation of high-performance absorbing materials in the future.