Black phosphorus quantum dots modified monolayer Ti3C2Tx nanosheet for field-effect transistor gas sensor

Ti3C2Tx MXene recently draws increasing attention in gas sensors, but their sensing performances, e.g., sensi-tivity, specificity, and ambient environment applicability, still needs improvement to meet the real application requirement. Herein, a black phosphorus quantum dots (BP QDs) modified Ti3C2Tx nanosheet (BQ/Ti3C2Tx) prepared by van der Waals self-assembly method is reported and applied as the sensing channel in field-effect transistor (FET) sensor. This sensor shows excellent NO2 detection performance at room temperature in terms of wide linear detection range (50 ppb to 10 ppm), short response time, and high specificity. Moreover, two important factors in practical gas detection, i.e., humidity and temperature, are systematically investigated. An efficient calibration strategy is proposed to eliminate the humidity effect, ensuring the accuracy of NO2 detec-tion. The mechanism study confirms that the enhanced sensitivity and selectivity are due to the increased adsorption energy of BQ/Ti3C2Tx for target gas molecules and the forming of P-O-Ti bond. This study offers new insights in the development of sensitive, selective, and reliable gas sensors with functionalized MXene materials.

Automated summary

This study reports a black phosphorus quantum dots modified Ti3C2Tx nanosheet, which shows excellent NO2 detection performance as the sensing channel in a gas sensor. The study also investigates the effects of humidity and temperature on the sensor performance and proposes an efficient calibration strategy to eliminate the humidity effect. The results demonstrate enhanced sensitivity and selectivity of the black phosphorus quantum dots modified Ti3C2Tx nanosheet.