WO₃-based Chemiresistive sensors for NO detection at low temperatures

Detecting hazardous gases (NOx, CO, and H₂), which significantly affect human health, is an important and challenging area of research. Early and rapid detection of these gases is vital to prevent long-term human health issues and to maintain good environmental conditions. By keeping these issues in mind, we have synthesized tungsten oxide (WO₃) nanorods using a simple and effective hydrothermal route to detect a 10 ppm concentration of NO gas. The calculated average crystallite size of WO₃ is 40 nm, demonstrating high crystallinity with a well-defined lattice structure as confirmed by the XRD and HR-TEM analysis. The reported sensor is chemiresistive in nature and exhibits modest sensitivity ∼6.5 % to detect 10 ppm concentration of NO gas at 50 °C. However, the reported sensor shows excellent sensitivity (58.8 %) and selectivity at 150 °C towards NO gas.