Revealing synergistic relationship of thermal conduction and electromagnetic shielding of reduced graphene oxide film

The present work tries to explore the evolution process of electro-magnetic interference shielding effectiveness and thermal conductivity of graphene film. There is an obvious promotion of electrical conductivity (from 3.51 × 10⁻³ to 769.20 S m⁻¹) when GO is thermally reduced at 1100 °C. Correspondingly, the reduced graphene oxide (rGO) achieves the highest EMI shielding effectiveness (∼54.84 dB) at 1100 °C which is a synergetic result of electrical conductivity and porous structure with rich defects. The rGO is furtherly graphitized at 2800 °C (G-rGO) to repair the defects and C–C network and then mechanically rolled to a densified film with bulk density of 1.64 g cm⁻³ (called as DG-rGO). The thermal conductivity of DG-rGO membrane increases to 720.56 W m⁻¹ K⁻¹ after graphitization and rolling. Porous structure and defects are beneficial to higher EMI shielding effectiveness while dense structure without defects lead to higher thermal conductivity. Therefore, the highest EMI shielding effectiveness and thermal conductivity cannot be obtained simultaneously. A reference range is provided to fulfill the request of EMI shielding and thermal conductivity.