Anchoring magnetic ZIF-67 on Ti₃C₂T_x MXene to form composite films with high electromagnetic interference shielding performance

With the rapid advancements of portable and wearable devices, high-efficiency electromagnetic interference (EMI) shielding materials are highly required to eliminate radiated electromagnetic pollution. Ti₃C₂T_x MXene has shown great application potential as an EMI SE material due to its good conductivity. However, a single-loss mechanism has many limitations. Herein, to enrich the electromagnetic-wave-loss ways, MXene@ZIF-67/multiwalled carbon nanotubes (MWCNTs) composite films were successfully prepared by vacuum-assisted filtration, combined with the introduction of magnetic ZIF-67 anchored on MXene by an electrostatic self-assembly method. The MXene@ZIF-67/MWCNTs composite film (MZ₂M₈) achieved the best EMI shielding performance of 63.6 dB at 32 μm thickness, and the contribution ratio of the scattering parameters for absorption to reflection, i.e., SE_A to SE_T, was 66.94%, thus achieving high absorption loss. Due to the high aspect ratio of the MWCNTs and the densely stacked “brick-mortar” layered structure, the composite film also exhibited excellent flexibility and mechanical performance, in which MZ₈M₂ could deliver a high tensile strength of 115.2 MPa, ensuring practical applications in different environments. Moreover, the thermal conductivity of MZ₂M₈ reached 3.367 W m⁻¹ K⁻¹, realizing the synergistic effect of high shielding efficiency and heat-dissipation performance, and avoiding the phenomenon of heat accumulation caused by the conversion of electromagnetic waves into heat energy.