H2S Gas Sensing Based on SnO2 Thin Films Deposited by Ultrasonic Spray Pyrolysis on Al2O3 Substrate

H2S gas is harmful for human health and environment, therefore novel gas sensors for real time and fast detection with high precision have been sought. Metal oxides are already known as promising candidate for this purpose. This article presents the performance of a gas sensor consists of a microheater and active layer formed on single alumina substrate for operating at high temperature applications. Ultrasonic spray pyrolysis deposition method was used to make both thick layer of SnO2 for microheater and thin and porous crystalline layer of SnO2 as sensing layer. The prepared sensor showed suitable dynamic response towards 10 to 50 ppm of H2S gas both in humid and dry conditions at 450°C. In these experiments, the cross sensitivity of the sensor was also checked for other interfering gases e.g. CH4 and NO2.