Highly sensitive NO2 gas sensor based on VS2/Ti3C2Tx/TiO2 nanocomposites

• Cost-effective and easy-to-operate chemo-resistive gas sensor for detecting NO 2 . • Excellent sensitivity of 4.73 at 180 °C to 50 ppm NO 2 , which is 2.5 times better than the Ti 3 C 2 T x /TiO 2 sensor. • The prepared gas sensor exhibit fast response/recovery speed. • The NO 2 sensing response mechanism of the nanocomposites is proposed. Elevated concentrations of nitrogen dioxide (NO 2 ) pose detrimental effects on the environment, contributing to pollution in water bodies, soil, and the atmosphere. Moreover, NO 2 , being a potent oxidant, can directly impinge upon the respiratory system, precipitating a range of pulmonary illnesses. Consequently, rigorous surveillance and assessment of NO 2 emissions are of paramount importance for safeguarding environmental integrity and public health. To address this challenge, we fabricated a NO 2 gas sensor using VS 2 /Ti 3 C 2 T x /TiO 2 nanocomposites. The sensors were thoroughly characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). In our tests, the M/v-2 sensor showed excellent performance, with a response of 4.73 at 180 °C to 50 ppm NO 2 , which is 2.5 times that of the Ti 3 C 2 T x /TiO 2 sensor. Additionally, its response time was short (26 s), the recovery time was even shorter than the response time (15 s), and it demonstrated a high response speed to low concentrations of NO 2 (≤10 ppm). Furthermore, the long-term stability was excellent over a period of 45 days. The gathered characteristics indicate that our VS 2 /Ti 3 C 2 T x /TiO 2 gas sensor has great potential for NO 2 detection.