Effect of preparation conditions on structure and electromagnetic wave absorption properties of sandwich-like Fe₃O₄-rGO nanocomposites

Fe3O4-intercalated reduced graphene oxide (Fe3O4-rGO) nanocomposites were prepared by an in-situ reduction method. We studied the effect of preparation conditions, including GO:Fe3+ molar ratio and reduction temperature, on the structure and electromagnetic wave absorption properties of the nanocomposites. The Fe3O4 rGO nanocomposites have a typical sandwich structure at a 1:1 M ratio. Increasing the reduction temperature above 500 degrees C yielded a relatively pure Fe3O4 crystalline phase. Furthermore, changes in the microstructure effectively influence the matching performance of the material. A reasonable molar ratio and reduction temperature yields a composite with improved impedance matching and thickness matching characteristics. M a ratio of 1:1 and reduction temperature of 600 degrees C, the actual matching thickness of the material conforms to the quarter-wavelength theory, and the input impedance of the material matches the air impedance. As a result, electromagnetic waves enter the interior of the composite unhindered, where they can be effectively attenuated, thereby further improving the wave absorption properties of the material. When the thickness is 3 mm, the maximum reflectance at 8.6 GHz reaches -49.6 dB with an effective bandwidth of 2.72 GHz.