Sandwich-structured graphene@Fe₃O₄@carbon nanocomposites with enhanced electromagnetic absorption properties

Sandwich-structured graphene@Fe₃O₄@carbon nanocomposites were prepared by a rational route. Transmission electron microscopy measurements show that an amorphous carbon layer is covered on the surface of graphene@Fe₃O₄ and the sandwich-structured graphene@Fe₃O₄@carbon is formed, and the TGA results indicate that the carbon content is 42.4 wt%. Compared with graphene@Fe₃O₄, the as-prepared graphene@Fe₃O₄@carbon nanocomposites 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@carbon is -30.1 dB at 14.8 GHz with a thickness of only 1.8 mm, and the absorption bandwidths with a reflection loss below -10 dB ranges from 12.1 to 17.5 GHz.