MXene-coated conductive composite film with ultrathin, flexible, self-cleaning for high-performance electromagnetic interference shielding

• The layered structure and sandwich structure film was prepared by bio-inspired strategy. • The composite films shown excellent conductivity (92.68 S/cm) and high tensile strength (93.55 MPa). • The composite films possessed high EMI SE of 32 dB and SSE/t of 4085.92 dB cm 2 /g. • The multifunctional composite films exhibited ultrathin, flexible, and self-cleaning. With the expanding utilization and development electronic devices, electromagnetic interference (EMI) shielding materials with good flexibility and lightweight have been desired to eliminate the radiation pollution. However, many EMI shielding materials are usually limited in practical application due to the large thickness and poor mechanical properties. Herein, ultra-thin and lightweight conductive composite films with both unique undulating layered structure and sandwich structure were constructed via a simple solution dip-coating method. The PAN@TiO 2 (PT) film as a substrate endowed the Ti 3 C 2 Tx film a certain strength, the polydopamine was decorated on the PT film surface to enhance the combination fastness of the PT film and Ti 3 C 2 Tx, and the Ti 3 C 2 Tx sheets built a conductive network. The conductive composite film (high tensile strength of 93.55 MPa) possessed an average EMI shielding effectiveness (SE) of 32 dB and a specific SE of 4085.92 dB cm 2 /g owing to their excellent electrical conductivity of 92.68 S/cm. The bio-inspired strategy provides a promising approach in fabricating flexible and ultrathin composite materials for highly efficient EMI shielding applications. Furthermore, this strategy offers a feasible idea for preparing multifunctional films.