Bioinspired, ultra-light and sandwich structured MXene–AgNWs/cellulose nanofiber porous film for excellent electromagnetic interference shielding with Joule heating performance

With the rapid development and popularization of intelligent, portable, and wearable flexible electronic devices, urgently required a new generation electromagnetic interference (EMI) shielding materials to manage the increasing serious radiation pollution. In this work, ultrathin, lightweight, and flexible porous films with reasonable strength were fabricated via vacuum filtered the cellulose nanofiber (CNF) dispersion on both sides of the MXene–AgNWs film and followed by a freeze-drying process. The prepared porous composite film presents to be a typical sandwich-structured with dense in surface and porous inside. This novel and unique structure endows the sandwich-structured porous film with greatly improved EMI performance to 67.5 from 40 dB, enhanced absorption coefficient from 0.1 to 0.4, and satisfactory mechanical properties with a tensile strength of 20.3 MPa, a strain at break of 2.1%. Furthermore, the prepared films present the remarkable low-voltage-driven Joule heating performance. Therefore, ultrathin, lightweight, flexible, and versatile properties CNF–MXene–AgNWs composite porous film with an excellent EMI-shielding performance is hold great potential in the fields of aerospace, portable and wearable electronics.