Nitrogen-Doped TiCT MXene Induced by Plasma Treatment with Enhanced Microwave Absorption Properties.

TiCT has microwave absorption (MA) properties due to its dielectric loss, but the absence of magnetic loss capability of pure TiCT causes unmatched impedance and unsatisfied MA performance. Modification of TiCT with magnetic particles is an effective way to introduce the magnetic loss mechanism. However, these modified TiCT particles have higher density and require complicated fabrication processes, restricting the industrial production and functional applications. Here, a low-temperature and simple method of radio-frequency N plasma treatment was adopted to modify TiCT with N. More interestingly, the N-doped TiCT flakes demonstrated magnetic properties and thus exhibited drastically enhanced MA properties. The minimum reflection loss (RL) of -59.20 dB at 10.56 GHz was achieved in N-doped TiCT products after only 3 min of plasma treatment, remarkably higher than RL of -11.07 dB at 7.92 GHz for the pristine TiCT. The main mechanism is due to the combination of dielectric loss, magnetic loss, and the good impedance matching in the N-doped TiCT. Further prolonging the nitriding time induces much desorption of -F and the formation of TiO, thus deteriorating the impedance matching and the MA properties.