Remarkable microwave absorption of GO-SiO2/Fe3O4 via an effective design and optimized composition

We present the design, synthesis, and characterization of the graphene oxide (GO)-SiO2/Fe3O4 nanocomposite as well as its applications for microwave absorption. The GO-SiO2/Fe3O4 nanocomposites were synthesized with three different compositions having mass ratios (1:1), (1:2), and (1:3). Graphene oxide was synthesized by the modified Hummers' method, while GO-SiO2 was hydrothermally synthesized, and GO-SiO2/Fe(3)O(4 )nanocomposites were obtained in a single pot process using different ratios of the mass of magnetite. Various characterization techniques were used to examine carefully the samples. SEM and TEM images show the creation of SiO2 and Fe3O4 nanoparticles on GO layers, which are confirmed by XRD. Next, we studied in detail the microwave absorption properties of all GO-SiO2/Fe(3)O(4 )composites. We have verified that GO-SiO2/Fe3O4 (1:3) with a high magnetic saturation of similar to 70.5 emu g(-1) and a corresponding layer thickness of 2 mm has excellent microwave absorption with a minimum reflection loss of -72.79 dB at 15.87 GHz and an effective absorption bandwidth (less than -10 dB) equal to 2.43 GHz (14.49-16.92 GHz). Besides, the maximum effective bandwidth reaches 7.54 GHz (10.46 -18.0 GHz) and 7.39 GHz (10.61-18.0) for thicknesses of 3.2 mm and 3.6 mm in samples (1:2) and (1:1), respectively. (C) 2020 Elsevier B.V. All rights reserved.