Designed fabrication of reduced graphene oxides/Ni hybrids for effective electromagnetic absorption and shielding

Reduced graphene oxide (rGO)/Ni hybrids with different mass ratio are successful synthesized in order to tune the microwave absorption together with the electromagnetic shielding performance. By properly adjusting the permittivity and permeability derived from different contents of the rGO and Ni, an rGO/Ni composite with excellent microwave absorption properties is obtained. An optimal reflection loss value of −39.03 dB at 13 GHz is achieved for the composite with rGO/Ni ratio of 1:1, and the bandwidth less than −10 dB can reach up to 4.3 GHz (from 11 to 15.3 GHz) with a thickness of 2.0 mm. Furthermore, the composite with rGO/Ni ratio of 4:1 shows superior electromagnetic shielding performance as high as 52 dB, which far surpasses the best value for most carbon-based materials. Fundamental mechanisms for absorbing and shielding performance are discussed.