Enhanced NO2 gas response of ZnO–Ti3C2Tx MXene nanocomposites by microwave irradiation

ZnO–Ti3C2Tx MXene nanocomposites with varying MXene contents (0.5, 1, 2, and 5 wt%) were synthesized for NO2 detection, and the impact of microwave (MW) irradiation time (1 to 8 min) on NO2 response was explored. It was observed that the sensor containing 2 wt% Ti3C2Tx MXene, irradiated for 5 min, indicated the best response of 42.65 to NO2 (10 ppm) at 300°C. Additionally, the optimal gas sensor demonstrated long-term stability (over six months), and reproducibility. The boosted NO2 response was ascribed to the creation of ZnO–MXene Schottky barriers, an increase in oxygen vacancies due to MW irradiation, a large surface area of the nanocomposite sensor, and the presence of surface groups on MXene. We confirmed the promising effects of MW irradiation in enhancing gas sensing, showcasing it as a cost-effective and readily available technique.