Anchoring magnetic ZIF-67 on Ti3C2Tx MXene to form composite films with high electromagnetic interference shielding performance†

Abstract

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.