Laminated Ti₃C₂T_x MXene has been considered as a promising absorbing material. However, microwave absorption (MA) performance of single Ti₃C₂T_x 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@Ti₃C₂T_x 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@Ti₃C₂T_x composites are regulated to enhance magnetic loss and improve impedance matching. The CoNi@Ti₃C₂T_x 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.

层合的Ti ₃ C ₂ T _x MXene被认为是有前途的吸收材料。但是，单一Ti ₃ C ₂ T _x MXene的微波吸收（MA）性能始终受到限制。事实证明，引入磁性元件可有效改善阻抗匹配和MA性能。本文通过简单的低温水热法原位制备了具有多种CoNi含量的新型CoNi @ Ti ₃ C ₂ T _x复合材料。通过引入不同含量的CoNi纳米粒子，CoNi @ Ti ₃ C ₂ T _x的电磁（EM）参数调节复合材料以增加磁损耗并改善阻抗匹配。具有40 wt％CoNi纳米颗粒的CoNi @ Ti ₃ C ₂ T _x复合材料在13.20 GHz处显示出−58.18 dB的强反射损耗，因为厚度仅为1.55 mm，可以实现5.68 GHz的宽有效吸收带宽。优异的MA性能可归因于自然共振，叠层结构的多次散射和反射，偶极极化和界面极化。这种低成本，节能且简单的方法对于MXene基复合材料的微波吸收应用具有重要意义。