MXene/FeCo films with distinct and tunable electromagnetic wave absorption by morphology control and magnetic anisotropy

MXene , an emerging two-dimensional (2D) material, is widely used as a microwave absorber to defense the electromagnetic pollution in the high-frequency communication. However, how to reasonably reduce the excessive conductivity of the single-layer MXene itself remains a challenge. Herein, via vacuum-assisted filtration, a flexible MXene/FeCo film was prepared by the electrostatic interaction between negatively charged MXene and positively charged FeCo alloy. The continuous layered structure composed of single-layered MXene stacking was destroyed due to the intercalation of the magnetic nanoparticles , resulting in the reduced conductivity and proper impedance matching. Because of the anisotropy associated with different morphologies, the rough surface of nanoflower-like FeCo alloy has better interfacial polarization and magnetic loss capabilities that induced by the more active response sites, confirming by electron holography. The MXene-FeCo nanoflower-like film demonstrated better microwave absorption (MA) performance with the maximum RL value of −43.7 dB at 3.76 GHz, while the RL max reached −36.2 dB at 10.16 GHz of MXene-FeCo nanoplate-like film. Thus this effective frequency adjustment also expands the practical applications of absorbers to deal with different frequency of the outer microwave changes. It is expected that regulating morphology might shed new light on the absorbers designing with tunable MA performance.