Porifera‐Inspired Lightweight, Thin, Wrinkle‐Resistance, and Multifunctional MXene Foam

Abstract Transition metal carbides/nitrides (MXenes) demonstrate a massive potential in constructing lightweight, multifunctional wearable electromagnetic interference (EMI) shields for application in various fields. Nevertheless, it remains challenging to develop a facile, scalable approach to prepare the MXene‐based macrostructures characterized by low density, low thickness, high mechanical flexibility, and high EMI SE at the same time. Herein, the ultrathin MXene/reduced graphene oxide (rGO)/Ag foams with a porifera‐inspired hierarchically porous microstructure are prepared by combining Zn 2+ diffusion induction and hard template methods. The hierarchical porosity, which includes a mesoporous skeleton and a microporous MXene network within the skeleton, not only exerts a regulatory effect on stress distribution during compression, making the foams rubber‐like resistant to wrinkling but also provides more channels for multiple reflections of electromagnetic waves. Due to the interaction between Ag nanosheets, MXene/rGO, and porous structure, it is possible to produce an outstanding EMI shielding performance with the specific surface shielding effectiveness reaching 109152.4 dB cm 2 g −1 . Furthermore, the foams exhibit multifunctionalities, such as transverse Joule heating, longitudinal heat insulation, self‐cleaning, fire resistance, and motion detection. These discoveries open up a novel pathway for the development of lightweight MXene‐based materials with considerable application potential in wearable electromagnetic anti‐interference devices.