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 Ti3C2Tx MXene. Oxygen plasma irradiation induced TiO2 formation on the Ti3C2Tx 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 Ti3C2Tx irradiated for 0.5 h (Ti3C2Tx-0.5P) was hundreds of times better than the pristine Ti3C2Tx 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 Ti3C2Tx and mesoporous structures which greatly improved the adsorption of ethanol. Additionally, the relatively low work function of TiO2 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.

Automated summary

This work introduces a surface modification strategy using oxygen plasma irradiation to enhance the room temperature sensing performance of Ti3C2Tx MXene. The irradiation induced the formation of TiO2 on the surface and improved the adsorption capability and response speed of the material. This method provides a facile and controllable approach for surface modification of other 2D materials.