Multilayered graphene-carbon nanotube-iron oxide three-dimensional heterostructure for flexible electromagnetic interference shielding film

Here, we report a rapid and straightforward microwave method to synthesize a multilayered and interconnected three-dimensional graphene-carbon nanotube-iron oxide (3D G-CNT-Fe2O3) heteronanostructure for a flexible and wideband high-performance electromagnetic interference (EMI) shielding film. The single integrated 3D G-CNT-Fe2O3 heteronanostructure that consists of carbon nanotubes, graphene sheets and iron oxide nanoparticles results in strong synergy from multilevel EMI shielding due to strong coupling among conduction loss, hysteresis loss and multiple scattering. As a result, multilevel reflection, absorption, and scattering processes are realized on the surfaces and interlayers of the 3D heteronanostructure, and much higher SE (Shielding effectiveness) values (130–134 dB) are observed in a bandwidth ranging from 8.0 to 12.0 GHz. As a whole, the thin and flexible composite film made with 3D G-CNT-Fe2O3 nanostructures and Poly(3,4-ethylenedioxythiophene) poly(4-styrenesulfonate) demonstrates excellent EMI shielding effectiveness over 130 dB and shows flexible and durable performance under repeated bending tests over 1000 times, without a remarkable degradation of the performance.