Electrostatic assembly of charge-modulated MXene and graphene oxide into conductive porous nanohybrids via rapid annealing for EMI shielding

With the proliferation of devices for 5 G communication and the advent of future mobility, the management of electromagnetic interference (EMI) has become crucial. While traditional metal-based films exhibit high EMI shielding effectiveness (SE), the demand for lightweight materials and structures for high energy efficiency is desired in future applications. This study presents an approach for fabricating electrically conductive and porous MXene-reduced graphene oxide (rGO) hybrids with improved EMI shielding performance through electrostatic assembly and rapid annealing techniques. Here, the GO surface was converted to a positive charge using poly(diallyldimethylammonium chloride) (PDDA) to induce electrostatic assembly with negatively charged MXene nanosheets. To induce extensive porous structures and simultaneously reduce graphene oxide to provide electrical conductivity, MXene-GO hybrid films were rapidly annealed at 600 °C. The resulting porous hybrid films exhibited significantly improved EMI shielding effectiveness in the X-band and Ka-band, with SE_T values increasing by up to 20 dB. It was also revealed that this increment was dominantly contributed by the increase in SE_A rather than SE_R. Furthermore, the hybrids demonstrated enhanced heat dissipation compared to pristine MXene EMI shielding films. We believe that our work proposes a facile fabrication method in developing advanced materials for EMI shielding applications in 5 G communication systems.