Investigating the sensing properties of SnO2-PdPt nanohybrid toward methane gas and effect of adding reduced graphene oxide on improving its sensing performance

In this paper, the sensing properties of SnO2-PdPt nanohybrid to methane gas and effect of reduced graphene oxide (rGO) on improving its sensing performance was investigated. For this reason, first SnO2 was synthesized by hydrothermal method and then hybridized by Pd, Pt and PdPt catalysts. For investigating the effect of rGO, by the in-situ hydrothermal method, SnO2-rGO was synthesized instead of SnO2. Results showed that the nanohybrid sensor with bimetallic alloy catalyst, had higher response t lower temperature compared with monometallic catalysts and on the other hand, adding rGO, reduced the optimum sensing temperature of SnO2-PdPt and enhanced its response to methane. The SnO2-PdPt nanosensor showed 52.22% response to 1000ppm CH4 at 200oC. The sensing response and recovery times for this hybrid were 94s and 3.5min respectively, whilst the SnO2-rGO-PdPt showed 69.5% response at 150oC to the same concentration of methane. The response and recovery times for this hybrid were 50s and 4.5min respectively.