Surface engineering of Ti3C2Tx MXene by oxygen plasma irradiation as room temperature ethanol sensor

In this work, a surface modification strategy by oxygen plasma irradiation was introduced for the first time to significantly improve the room temperature sensing performance of Ti 3 C 2 T[Formula: see text] MXene. Oxygen plasma irradiation induced TiO 2 formation on the Ti 3 C 2 T[Formula: see text] surface, produced lattice distortion, increased the specific surface area, and provided mesoporous structures. The gas sensitivity performance characterization results show the gas response value of Ti 3 C 2 T[Formula: see text] irradiated for 0.5 h (Ti 3 C 2 T[Formula: see text]0.5P) was hundreds of times better than the pristine Ti 3 C 2 T[Formula: see text]alongside with its sufficient response time (280 s) and rapid recovery time (11 s). The excellent sensing performance is attributed to the formation of more reactive sites on the edge and basal planes of Ti 3 C 2 T[Formula: see text] and mesoporous structures which greatly improved the adsorption of ethanol. Additionally, the relatively low work function of TiO 2 facilitates the formation of a Schottky junction for easy migration of charge carrier, the thereby shortening the sensing response time. This strategy offers a facile and controllable surface modification of other 2D materials, without damaging their structures.