Supraparamagnetic quaternary nanocomposites of graphene@Fe ₃O₄@SiO₂@SnO₂: Synthesis and enhanced electromagnetic absorption properties

Supraparamagnetic quaternary nanocomposites of graphene@Fe ₃O₄@SiO₂@SnO₂ were prepared by combing the versatile sol-gel process and hydrothermal reaction. Transmission electron microscopy measurements show that Fe₃O₄@SiO ₂@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@SnO ₂ 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.