Cerium oxide/SnO2-based semiconductor gas sensors with improved sensitivity to CO

SnO2-based semiconductor gas sensors have been successfully fabricated and tested for detecting carbon monoxide and methane. The sensitivity and selectivity of the sensors are tailored by incorporation of different additives such as platinum and cerium oxide. While platinum enhances the sensor response to CH4, ceria suppresses its sensitivity in favor of carbon monoxide. The effect of operating temperature on the performance of sensors is reported. Addition of 10% cerium oxide in the SnO2 sample leads to an insignificant response to methane even at an elevated temperature of 450 degreesC, while its response to CO remains intact. (C) 2001 Elsevier Science B.V. All rights reserved.