In situ deposition of pitaya-like Fe3O4@C magnetic microspheres on reduced graphene oxide nanosheets for electromagnetic wave absorber

Reasonable nanostructure design and composition are conducive to the electromagnetic wave (EM) absorption behavior of absorbers. Herein, Fe3O4@C/reduced graphene oxide (rGO) nanocomposites with layered structure were fabricated by a feasible solvothermal method. By adjusting the amount of grapuhene oxide (GO), different dielectric characteristics and impedance matching conditions of Fe3O4@C/rGO nanocomposites could be obtained. Moreover, with amorphous carbon as the matching layer, Fe3O4 and rGO provide strong magnetic loss and dielectric loss, respectively. The results exhibit that Fe3O4@C/rGO nanocomposites own salient EM absorption properties under the combined action of various components and three-level layered structure. In addition, the Fe3O4@C/rGO-20 nanocomposites (the addition of GO is 20 mg) are endowed with the best EM absorption performance, which demonstrates a minimum reflection loss (RLmin) value of -59.23 dB at 6.24 GHz with a sample thickness of 3.57 mm and effective absorption bandwidth (EAB) is 6.72 GHz. Moreover, the widest EAB is 8.24 GHz at a thinner thickness of 2.6 mm with the RL value of -25.80 dB at 14 GHz. This work could be a reference for lightweight, broadband, strong absorption composite absorber.