Advanced 2D nanosheet-based gas sensor for sensitive detection of low concentration NO₂ gas using In₂O₃/Ti₃C₂ layers

The detection of small quantities of hazardous and flammable gases at room temperature is crucial for protecting human health and the environment. In this study, the indium oxide (In2O3) and MXene (Ti3C2) were prepared separately using different techniques and then combined to form a composite through sonication in an ethanol solution. The findings from the gas-sensing performance revealed that the In2O3/Ti3C2 nanocomposites had very high response values of 3785.01 and 33.84 towards 100 and 10 ppm NO2 gas at the optimal working temperature (150 C) respectively. The In2O3/Ti3C2-1 composite has a strong linear relation (R2 = 0.9869), it is reproducible and has prolonged detection stability. The occurrence of oxygen vacancies and the creation of Schottky barriers are principally responsible for the outstanding gas-sensing capabilities reported. The computed response and recovery times were 24 and 56 s respectively under 100 ppm NO2 environment showing strong selectivity toward the gas. This research combines density function theory (DFT) to investigate the room-temperature gas sensitivity of indium oxide-MXene nanocomposites, shedding new light on how to optimize the materials for practical applications in wearable and low-energy consumption devices.