Growth of WO3–SnO2 Composite Using Chemical Method for NO2 Sensing

With the degrading air quality around the globe, the detection of air pollutants has attracted increasing interest. NO2 is a major contributor towards air pollution in urban areas mainly due to emissions from automobiles and industries. Exposure to high NO2 levels can lead to a range of human health complications and increased levels can have an adverse effect on the environment as well. In order to understand people’s exposure to air pollution and take action when necessary, there is a need for fast, sensitive, and portable real-time sensing devices. The present work focuses on development of conductometric gas sensor based on Tungsten Trioxide-Tin Oxide (WO3–SnO2) composite films developed using chemical solution deposition (CSD) technique for the detection of NO2 gas. The gas sensing parameters were studied and compared for WO3–SnO2 composite sensors as well as for pristine SnO2 and WO3 sensors in the temperature range of 30–180 °C towards 10 ppm of NO2 gas. A high sensing response of ~ 286 was obtained at a low operating temperature of 110 °C for the WO3–SnO2 composite sensor.