Interdigitated electric-magnetic gradient MXene-based nanocomposite films for concurrent high-efficiency electromagnetic shielding and sensitive detection

The proliferation of electronic devices has intensified electromagnetic (EM) radiation pollution, creating an urgent demand for high-performance electromagnetic interference (EMI) shielding and detection materials. However, achieving the simultaneous combination of superior shielding effectiveness (SE), reduced reflection, high-sensitivity electromagnetic waves (EMWs) detection, and mechanical robustness remains a formidable challenge. Herein, we report a novel MXene-based EMI shielding composite film featuring an interdigitated electric-magnetic gradient (IEMG) architecture fabricated through alternating vacuum-assisted filtration. The IEMG structure enhances impedance matching at the air-film interface, thereby mitigating EMWs reflection, while the integrated electric-magnetic coupling network enables multiple attenuation mechanisms. Consequently, the optimized film achieves an EMI SE of 59 dB with a reduced reflection SE (SE_R) of 4.8 dB, corresponding to a reflection coefficient of R = 0.67. Leveraging the highly conductive MXene/CNF layer with electromagnetic induction effects, the film detects environmental EM radiation with a sensitivity of 99.59%. Furthermore, the multilayered structure and strong hydrogen-bonding interactions confer exceptional mechanical properties on the film, including a tensile strength of 125 MPa. Additionally, the intrinsic electric conductivity of MXene enables excellent thermal management via Joule heating (reaching a saturation temperature of 118 °C at 3 V within 10 s) and infrared stealth due to its low infrared emissivity of 0.3. This study presents an innovative strategy for constructing robust, multifunctional, and intelligent films with high EMI SE, reduced reflection, and high-sensitivity EM detection, demonstrating significant potential for next-generation wearable electronics, precision equipment protection, and military applications.