A PdPt decorated SnO2-rGO nanohybrid for high-performance resistive sensing of methane

SnO2, SnO2-PdPt, and PdPt decorated SnO2-rGO (SnO2-rGO-PdPt) samples were presented to use in resistive sensing of methane. A hydrothermal method was used to synthesize SnO(2 )and SnO2-rGO and these were then easily doped with PdPt catalyst by in situ reductions of their metallic salts. The responses to gaseous methane at levels between 500 and 10,000 ppm were measured in the temperature range of 50-250 degrees C. Results demonstrated that the dopants can increase the response of SnO(2 )sensor toward 1000 ppm methane from 12.5% (for bare SnO2) to 32.7% (for SnO2-PdPt) and 69.5% (for SnO2-rGO-PdPt) at 150 degrees C. In addition, the optimum operating temperature was reduced from 300 degrees C (for SnO2) to 150 degrees C (for SnO2-rGO-PdPt). The catalyst also improved the stability during continuous cycles. The response and recovery times of SnO2-rGO-PdPt sensor at 150 degrees C and flow rate of 160 sccm of 1000 ppm methane, were 50s and 4.5 min respectively. A sensing mechanism is suggested in details. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.