Ultralow-content Co decoration on Ti3C2Tx MXene induced electromagnetic characteristic modulation for efficient microwave absorption

Ti3C2Tx MXene has been regarded as a promising candidate for advanced microwave absorption materials. However, the microwave absorbing performance of Ti3C2Tx MXene is suppressed by the single dielectric loss mechanism and impedance mismatch because of the high conductivity. To effectuate a good absorption capability of Ti3C2Tx MXene, this paper constructs a heterostructured Co/Ti3C2Tx hybrid by atomic layer depositing magnetic Co nanoparticles on Ti3C2Tx nanosheets. The microstructures, magnetism, and microwave absorption behaviors of the Co/Ti3C2Tx hybrids are investigated systematically. The results show that the frequency-dependent electromagnetic parameters of the Ti3C2Tx Mxene become tunable by controlling the content of Co decorations, which are conducive to both magnetic loss and impedance matching. The Co/Ti3C2Tx hybrid with ultralow Co decoration content (only 1.52 wt.%) achieves the minimum reflect loss of -54.32 dB at a thin matched thickness of 1.29 mm, and the corresponding effective absorption bandwidth with reflection loss below -10 dB reaches 4.29 GHz. The atomic layer deposited magnetic metal nanostructures provides an effective strategy for preparing MXene-based hybrids which not only have high absorption efficiency but also significantly reduce the use of magnetic metals.