Study on the electromagnetic wave absorption performance of Ti3C2 MXene with different etching states

In this paper, a safe, low-cost and simple operating LiF + HCl etching method combined with freeze-drying was used to prepare Ti3C2TX MXene with different etching states. The results indicated that the morphology of Ti3C2TX gradually changed from stacked to accordion structure and finally to ultra-thin dispersed sheets with increasing etching. We also investigated different surface functionalization and electromagnetic properties of synthesized samples. In 2–18 GHz, the effective absorption bandwidth (EAB) (RL < − 10 dB) of the sample with accordion microstructure reaches 3.92 GHz at thickness of 1.27 mm, while for the ultra-thin dispersed Ti3C2TX sheets, the EAB is increased to 4.40 GHz at thickness of 1.26 mm. To our knowledge, this is the minimum thickness in Ti3C2-related reports. We attribute the improved wave absorption performance to the dielectric and magnetic loss induced by termination layer as well as the unique interface effects, which are also beneficial to optimize the impedance matching and achieve multi-mode attenuation even in high frequency band.