Synthesis and strengthened microwave absorption properties of three-dimensional porous Fe3O4/graphene composite foam

The three-dimensional porous Fe3O4/graphene composite foam as a new kind of absorbing composite with electrical loss and magnetic loss was successfully synthesized by a facile method. Fe3O4 was evenly attached on structure of graphene sheets which overlapped with each other to form three-dimensional porous graphene foam. The results revealed that when the mass ratio of graphene oxide (GO) and Fe3O4 was 1:1, the Fe3O4/graphene composite foam possessed the best absorption properties: the minimum reflection loss was up to -45.08 dB when the thickness was 2.5 mm and the bandwidth below -10 dB was 6.7 GHz when the content of the composite foam absorbents was just 8%. The micron-sized three-dimensional porous structure provided more propagation paths, enhancing the energy conversion of incident electromagnetic waves. The addition of Fe3O4 contributed to improving the impedance matching performance and magnetic loss. The three-dimensional porous Fe3O4/graphene composite foam was a kind of high-efficiency wave absorber, providing a new idea for the development of microwave absorbing materials.