3D printing of resilient, lightweight and conductive MXene/reduced graphene oxide architectures for broadband electromagnetic interference shielding

Lightweight and conductive macroscopic MXene-based architectures receive tremendous attention for various potential applications. However, conventional methods are incapable of producing customized structures with controllable functionality and performances. Herein, we demonstrate a three-dimensional (3D) printing of lightweight, resilient, and conductive MXene-based scaffolds with customizability and shape-adaptability by a direct ink writing (DIW) technique. The rheology and printability of the MXene inks are optimized by adding graphene oxide (GO) microgels, ensuring the self-supporting capability of the printed architectures with good structural integrity and connectivity. Moreover, the structure design flexibility and conformation tunability offer unique superiorities to optimize the comprehensive performances of the printed MXene/reduced graphene oxide (RGO) scaffolds. As a result, the lightweight MXene scaffolds show a high electrical conductivity of 1013 S m−1 and a broadband tunable electromagnetic interference (EMI) shielding effectiveness (SE) of above 60 dB in the frequency range of 8.2–26.5 GHz. An optimal value of ∼100 dB and an ultrahigh normalized surface specific SE of up to 19 270 dB cm2 g−1 are far superior to the results of other 3D printed EMI shielding materials. Meanwhile, the hierarchical and robust architectures also deliver an outstanding reversible compressibility of up to 90% strain as well as excellent cyclic fatigue resistance, surpassing the reported rigid and brittle printed MXene structures. This work provides helpful inspiration for structural design and potential applications of 3D printed MXene-based architectures in many areas.