Supraparamagnetic quaternary nanocomposites of graphene@Fe3O4@SiO2@SnO2: Synthesis and enhanced electromagnetic absorption properties

Abstract Supraparamagnetic quaternary nanocomposites of graphene@Fe3O4@SiO2@SnO2 were prepared by combing the versatile sol–gel process and hydrothermal reaction. Transmission electron microscopy measurements show that Fe3O4@SiO2@SnO2 core–shell–shell nanostructures are fabricated on graphene surface. Compared with graphene@Fe3O4, the as-prepared graphene@Fe3O4@SiO2@SnO2 composites exhibit enhanced microwave absorption properties in terms of both the maximum reflection loss value and the absorption bandwidth. The maximum reflection loss of graphene@Fe3O4@SiO2@SnO2 is −37.4 dB at 15.1 GHz and the absorption bandwidth with the reflection loss below −10 dB range from 12 to 18 GHz with a thickness of 2 mm. Thus, the nanocomposites may have the potential as high-efficient absorber for microwave absorption applications.