Controlled etching of MXene for highly selective triethylamine detection at room temperature

MXene, exemplified by Ti3C2Tx, was obtained as a viable candidate for sensing gases at room temperature. However, in the current study, increased power consumption and poor process reproducibility resulted from the long cycle times to prepare MXene and MXene-based gas-sensitive materials. In this study, a six-sided high -intensity ultrasonic wave was applied to the etching environment, and a series of MAX-MXene heterostructures were effectively obtained in one step by adjusting the etchant content. Due to the unique structure of MXene flake and the generation of endogenous MAX-MXene heterostructure, the MAM gas sensor exhibits a response value of 4.1% to 10 ppm TEA at room temperature (23 degrees C) and relative humidity of 84%, providing fast response recovery time, low electric noise and excellent selectivity, with a comprehensive gas sensing performance superior to that of the pristine MXene materials reported before. This study provides new ideas for designing and applying new substrate materials based on MAX and MXene.