Graphene Oxide/Carbon Tube Composite Films with Tunable Porous Structures for Electromagnetic Interference Shielding

Carbon nanomaterials have received extensive academic attention in the field of electromagnetic interference (EMI) shielding due to their light weight and high electrical conductivity. Employing one-dimensional carbon tubes to construct macro-assembly EMI shielding material architectures accompanied by generating pores in materials remains crucial. Herein, we employed a new type of carbon tube with a whisker structure and excellent electrical conductivity, named as whisker CT (wCT), and used graphene oxide (GO) as a bridging and foaming agent to achieve a porous reduced graphene oxide/wCT film (rGWF) by the vacuum-assisted filtration and annealing process. The rGWF with an average thickness of ∼30 μm exhibited outstanding electrical conductivity of 4.96 × 103 S/m and excellent EMI shielding effectiveness of 45–58 dB in the broad frequency range of 8.2–40 GHz. In addition, EM simulation was conducted by using the COMSOL software, and it confirmed that the porous structures induced by GO during the thermal reduction process changed the polarization direction and distribution of the electric field of attenuated EM waves. Moreover, the remarkable near-field shielding performance of 25–50 dB in the frequency range of 1–9 GHz was evaluated, which demonstrates the potential application of rGWF in electronic packaging.