Fabrication of NiO based thin film for high-performance NO2 gas sensors at low concentrations

Recent industrial and technical developments continuously result in the release of dangerous and toxic gases that have adverse effects on human life and the environment. Metal oxide nanomaterials attract attention for extremely sensitive gas sensors owing to their high surface-to-volume ratio, thermal stability, availability, and simplicity of production. Currently, p-type NiO based gas sensors are very promising, due to their outstanding repeatability, high sensitivity, low cost, and environmentally friendly characteristics. In this work, NiO prepared by low-cost hydrothermal method and its gas sensing behavior towards NO2 gas has been studied in detail. The as-prepared structure of NiO has been analyzed by using various characterization techniques like XRD, FESEM, FTIR, BET and UV-visible absorption for the study of structural, morphological and optical properties. The NiO thin film deposited on a glass substrate was analyzed under varying concentrations of NO2 at different working temperatures (100-250 degrees C). The sensor demonstrated a remarkable sensitivity of 45 % to 10 ppm of NO2 at low operating temperature of 200 degrees C. Moreover, its consistent repeatability further underscores its reliability, emphasizing its suitability for accurate and dependable NO2 detection in diverse scenarios.