Design of Ti₃C₂T_x/SnO₂-Selective Ethanolamine Sensor

Abstract

Two-dimensional transition metal carbides/nitrides (MXenes) show great potential in volatile organic compound (VOC) sensors owing to their exceptional electrical properties, numerous active sites, and abundant terminal functional groups. However, pure MXene Ti3C2Tx is prone to oxidative degradation under ambient environment, and the insufficient response and poor stability are still grand challenges. Hereby, by deliberately introducing metal oxide semiconductor in multilayer Ti3C2Tx, a promising Ti3C2Tx/SnO2 sensor with excellent long-term stability and outstanding selectivity is developed for VOC monitoring. The research shows that the Ti3C2Tx/SnO2 hybrid sensor implements efficient detection of hydrogen-bonded gases and is especially highly efficient with ethanolamine (EA). The sensitivity of the hybrid sensor to EA is improved by over 10-fold in comparison with pristine Ti3C2Tx, besides the good selectivity to over 12 different VOCs. The synergistic effects of n-n nanoheterojunctions, the large specific surface area of 45.186 m2/g and mesoporous-rich hierarchical structure, and the functional terminal groups together facilitate the EA-sensitive properties. In addition, the innovative preparation of the Ti3C2Tx/SnO2 sensor, which takes advantage of terpinol, contributes to the close contact of Ti3C2Tx/SnO2 on the ceramic tubes, thus improving the sensor sensitivity. The scientific findings of this work may provide valuable ideas for the exploration of innovatively composite gas sensors.