In situ decoration of Zn2SnO4 nanoparticles on reduced graphene oxide for high performance ethanol sensor

Developing novel metal oxide semiconductor (MOS) gas-sensing materials with high performance has attracted much attention in the field of gas sensor. In this work, Zn2SnO4 nanoparticles/reduced graphene oxide (ZTO/RGO) nanocomposites with various contents of RGO were successfully synthesized via a solvothermal method combined with subsequent annealing process. Through the present method, ZTO nanoparticles with the size about 20 nm were in situ decorated on the surface of RGO nanosheets. The results of gas-sensing tests indicated that the as-prepared ZTO/RGO showed an enhanced sensing performance to ethanol in comparison with pure ZTO. The response of the sensor fabricated with 8ZTO/RGO (with the optimal mass ratio of ZTO:RGO = 8:1) to 100 ppm ethanol at the optimal operating temperature of 275 degrees C is as high as 38, which is about 6 times higher than that of the bare ZTO sensor. Besides of high sensitivity, the 8ZTO/RGO sensor also showed impressive selectivity and fast response/recover behavior, as well as good linearity in a relatively wide range of ethanol concentration (5-1200 ppm). These good sensing characteristics make 8ZTO/RGO a promising candidate for practically detecting ethanol. The gas-sensing mechanism of the composite to ethanol was also discussed in detail.