Tailoring microwave electromagnetic responses in Ti3C2Tx MXene with CoNi-alloy nanoparticles decoration via mildd hydrothermal method

Laminated Ti3C2Tx MXene has been considered as a promising absorbing material. However, microwave absorption (MA) performance of single Ti3C2Tx MXene is always limited. The introduction of magnetic components has been proven to improve impedance matching and MA performance effectively. In this paper, a novel CoNi@Ti3C2Tx composites with various CoNi loading were in-situ fabricated via a simple and low-temperature hydrothermal method. By introducing different contents of CoNi nanoparticles, the electromagnetic (EM) parameters of CoNi@Ti3C2Tx composites are regulated to enhance magnetic loss and improve impedance matching. The CoNi@Ti3C2Tx composites with 40 wt% CoNi nanoparticles showed a strong reflection loss of -58.18 dB at 13.20 GHz as the thickness is only 1.55 mm and a broad effective absorption bandwidth of 5.68 GHz can be achieved. The superior MA performance can be attributed to natural resonance, multiple scattering and reflection of the laminated structure, dipole polarization and interfacial polarization. This low-cost, energy saving and simple method is significative for microwave absorption applications of MXene-based composite materials.