Ti2CTx MXene: A novel p-type sensing material for visible light-enhanced room temperature methane detection

Abstract The development of semiconductor-based room-temperature methane (CH4) gas sensors is appealing but challenging. Herein, we report a CH4 gas sensor operating at room temperature based on Ti2CTx MXene, a novel p-type sensing material, achieving high-performance CH4 detection with visible light assistance. The Ti2CTx MXene based device showed more than seven-fold improvement for CH4 detection under visible-light irradiation, and the response/recovery times were also sharply decreased. The excellent CH4 sensing performance at room temperature could be attributed to the visible-light photocatalytic CH4 oxidation activity of the Ti2CTx sensing material. CH4 oxidation was revealed by photocatalytic measurement, O2-TPD and in-situ IR spectroscopies. The present work demonstrates the novel application of Ti2CTx MXene as a promising p-type sensing material for methane detection at room temperature. Moreover, the concept of “photocatalysis-enhanced gas sensing” can be employed in room-temperature gas sensors based on other novel semiconductors.