Flexible MXene/Graphene oxide films with long-lasting electromagnetic interference shielding performance

MXenes are highly promising as electromagnetic interference (EMI) shielding materials owing to their high mechanical strength, light weight, high electrical conductivity, and processability. However, MXenes readily degrade in humid environments, which has limited further studies on these materials and their commercial application. Herein, we present a feasible strategy for protecting Ti3C2Tx MXene films by coating them with graphene oxide (GO) sheets with sequential filtration method, i.e., filtrating GO into a film firstly, then the MXene is filtered into a film on the top of GO, and finally the filtration is covered with another GO film. GO sheets not only protect Ti3C2Tx MXene from oxidation but also form a heterogeneous interface with it to increase losses and optimize impedance matching between the EMI shield and air. The GO dosage was explored to optimize the process to improve the EMI shielding performance of the GO-coated Ti3C2Tx MXene film. Free-standing films composed of GO/Ti3C2Tx MXene/GO (GMG) layers exhibit relatively stable EMI shielding per-formance over 70 days. Furthermore, as the GO dosage influences the stability of the GMG film, it was optimized to achieve sufficient coating of the Ti3C2Tx MXene layer with a short processing time to prevent the degradation of the already deposited Ti3C2Tx MXene and GO layers. This strategy based on structural design can lead to the development of low-cost and practical MXene-based EMI shielding materials with long-lasting EMI shielding performance.