Metal oxide catalyst assisted SnO2 thin film based SO2 gas sensor

Sulfur dioxide (SO2) is one of the most toxic and hazardous gas having adverse effect on the health and environment. In the present report, an attempt is made to fabricate SO2 gas sensor using SnO2 thin film integrated with various metal oxide catalyst (PdO, CuO, NiO, MgO, V2O5) in the form of 10 nm thin dotted clusters of 600 mu m diameter. The structural, optical and surface morphological properties of the SnO2 thin film have been studied. The bare SnO2 thin film sensor exhibits the sensing response of about 1.3 at 220 degrees C whereas, NiO/SnO2 sensor shows the enhanced sensing response (similar to 56) towards 500 ppm SO2 gas at a relatively low operating temperature (180 degrees C). A correlation has been established between the observed sensing response and the properties of the sensing film. Selectivity of the NiO/SnO2 sensor was tested towards different interfering gases and found to be highly selective for SO2 gas. (C) 2015 Elsevier B.V. All rights reserved.