Component controllable of graphene/NiO composite with superior shielding of microwave wave ability based on dielectric dissipation

As a classic two-dimensional (2D) material, graphene has been regarded as a potential electromagnetic (EM) shielding material, owing to the excellent conductivity, dielectric loss ability and chemical stability. Recent advances proved that graphene possessed the ultrahigh EM-shielding coefficient, but the shielding mechanism was mainly original from the strong wave reflection, hence has inevitably resulted in the second EM pollution. To reduce the wave reflection, herein, a component tunable of graphene/NiO composites have been produced via loading the NiO nanoparticles on the graphene nanosheets. Due to the smaller dielectric value of loaded NiO, the as-prepared graphene/NiO has moderately permittivity value, thereby would increase the incomings of microwaves. Meanwhile, the graphene/NiO has desirable dielectric loss ability, which enabled to dissipate the incomings of microwave into heats. To strengthen the microwave dissipating ability, the component of NiO has been optimized. The resulted shows the EM shielding coefficient could reach 22 dB under a thickness of 1.2 mm. While the microwave reflection coefficient (SE R ) could be reduced to 5.8 dB, suggesting the absorption dominate ability. According to this result, it can be found that employing a metal oxide that low in dielectric is an efficient method for developing high-performance absorption-dominate EM-shielding material.