Highly sensitive $Ti_3C_2$ MXene gas sensor for the selective detection of chemical agents

Abstract

Highly sensitive sensing of VOCs such as acetone and ammonia can be employed as clinical use in detection several disease. Various materials are having been studied to develop such sensitive sensor such as metal oxide and two dimensional materials (2-D materials). However, due to its wide band gap properties, metal oxide based channel only can be operated in high temperature ($200 ~300^\circ C$), which will not be applied in portable devices. On the same way, various band gap materials of 2-D materials are studied in sensor to solve room temperature operation. However, these 2-D materials gas sensors possess limited sensitivity due to the trade-off between gas response and electrical noise. Here, we experimentally demonstrate prospective of $Ti_3C_2$ metallic MXene gas sensor and investigate its properties for the first time. Our metallic sensor shows two significant advantages that it shows low noise induced by metallic conductivity and high signal for abundant hydrophilic surface group. As a result, these yield high signal to noise ratio toward gases and our device can possibly detect very high diluted VOCs (50~100ppb) which is criteria for clinical use. With these unique surface group and its metallic conductance, $Ti_3C_2$ MXene shows exclusive performance in chemical sensors at room temperature and we first demonstrate an insight how metallic sensor can be employed as chemical sensors.