Flexible and ultrathin GO@MXene sandwich-type multilayered film toward superior electromagnetic interference shielding in a wide gigahertz range of 3.95–18.0 GHz

Conductive MXene-based films are potential in electromagnetic interference (EMI) shielding. However, multilayered MXene-based films are rarely reported, and the EMI shielding investigations are confined in only X band (8–12 GHz). Herein, sandwich-type multilayered GO@MXene films were constructed by an alternating vacuum-assisted filtration technique. Benefiting from interlayer scattering and high conductivity, the flexible multilayered GO@MXene films show excellent EMI shielding performance in 3.95–18.0 GHz at an ultrathin film thickness. The mechanical properties and EMI shielding performance are related to the layered structure, film thickness and content of MXene. Especially, the trilaminar GO@MXene film (only ∼8 µm) shows superior EMI shielding and mechanical properties. The average EMI shielding effectiveness (SE) values are 44.5, 46.6 and 45.0 dB at C, X and Ku bands, respectively, with the corresponding specific EMI SE values of 22,429.4, 23,487.9 and 22,681.5 dB cm2 g−1. The GO@MXene film exhibits remarkable stability in acid, alkaline and organic solvent. This work not only provides a flexible film with high EMI shielding performance at a wide gigahertz range, but also suggests that the mechanical properties and EMI shielding can be tuned by simply changing the layered structure. This is helpful to give guidance to the design of novel MXene-based EMI shielding films and expand their applications.