▎ 摘　　要

SnO2 was ultrasonically deposited (precipitated) in the presence of different amounts of graphene oxide (GO) prepared by the modified Hummers' method. The resulting nanocomposites were used as sensing material for the detection of 1000 ppm CO and VOCs including ethanol, acetone and toluene, and CH4 in a temperature range of 150-300 degrees C. The nanocomposites were characterized by Raman spectroscopy, XRD, BET surface area measurement, FT-IR, and SEM methods. It seems that SnO2 layers were deposited on the GO surface and incorporated into the matrix. This resulted in 47% increase in the nanocomposite BET surface area. The addition of 0.1 wt% GO to SnO2 increased the response to CO by about 6 times at 300 degrees C. 0.05 wt% GO as an optimum amount was included in SnO2 up to 2-fold enhancement in response to ethanol, and toluene was observed. At 250 degrees C, the highest response to ethanol was obtained, which is 120, 114, 1400, and 15 times larger than the responses to CO, toluene, methane and acetone, respectively, making the sensors quite selective to ethanol. Furthermore, this sensor exhibited good response in the low concentration of ethanol. (c) 2017 Sharif University of Technology. All rights reserved.