Ultrathin CoNi@Ti3C2Tx composites with sandwich structures for efficient microwave absorption

Abstract

To obtain high-performance electromagnetic absorbing materials, we designed CoNi@Ti3C2Tx composites by a simple solvent thermal reduction method. Herein, we report the successful decoration of 80 nm CoNi alloy particles on the surface and interlayer of Ti3C2Tx. The calculated results show that the introduction of CoNi particles into the composites leads to dielectric loss and increases in Ms and Hc, significantly enhancing the soft magnetic properties of the CoNi@Ti3C2Tx composites. After adjusting the electromagnetic parameters, the optimal RL value of −51.5 dB is obtained at the frequency of 13.9 GHz, and the corresponding thickness is only 1.1 mm. The expected impedance matching and electromagnetic attenuation properties of the CoNi@Ti3C2Tx composites are attributed to synergic dual loss mechanisms – dielectric loss and magnetic loss – between the CoNi alloy particles and Ti3C2Tx. These are mainly due to conduction loss, dipole polarization, and interface polarization, as well as natural resonance and eddy current losses generated by CoNi nanoparticles. The lightweight and highly reflective CoNi@Ti3C2Tx composites are promising for applications as highly effective electromagnetic absorbers.