Ultrasensitive gas sensor based on Gd Modified SnO2 for nitrogen dioxide detection at low temperature

The current investigation highlights the successful development of a highly selective and ultra-sensitive nitrogen dioxide sensor at room temperature (28 ℃), employing Gd-doped SnO 2 nanostructures. A facile hydrothermal route prepared the pure and Gd-doped SnO 2 nanostructures. The samples were analyzed using XRD, HR-TEM, XPS, and BET analysis to investigate their structural, core-level morphology, chemical composition, and specific surface area properties. The prepared sensors exhibited superior selectivity towards the NO 2 gas molecule compared to other target gases such as H 2 S, CH 4 , NH 3 , SO 2 , acetone, ethanol, and methanol. Remarkably, the Sn-2 (3   mM) sample shows a superior gas-sensing response of about 186 towards the 10 ppm of NO 2 gas molecule at 28 ℃. At 100 ℃, the Sn-2 (3   mM) sample displays a sensing response of about 3726 towards the 10 ppm of NO 2 gas. In addition, the prepared pure and Sn-2 (3   mM) sensors showed good repeatability and stability. The results will give an alternative way to develop the metal oxide-based (MOS) NO 2 gas sensor for real-time gas monitoring applications. Additionally, DFT gas adsorption studies were conducted to better understand the selectivity performance of the pure and Gd-SnO 2 system, and the results showed good consistency with the experimental findings.