Study On Gas Sensing Properties Of Graphene/SnO 2 Composites For Natural Gas

As people pay more and more attention to the concepts such as “energy saving” and “environmental protection”, natural gas has entered people's life and becomes one of the indispensable energy sources. Nevertheless, due to methan's?the principal component of natural gas? flammable and explosive feature, it is needed to be monitored. So far, people have developed a variety of methane sensors, but the sooner people find the leakage of natural gas, the easier they protect their lives and property safety. Therefore, it is of value and significance to develop one faster, more sensitive and more accurate methane sensor. In recent years, the new type of nanomaterial——graphene stand out, since the performance of methane sensor is expected to reach new heights due to graphene's advantages in the applications of the semiconductor sensors' field. In this thesis, graphene/SnO₂ materials prepared by sol-gel method are used for the methane sensor with the high sensitive.On the basis of reading numbers of domestic and foreign references, different kinds of graphene/SnO₂ methane sensors are prepared by controlling different chemical components, sintering temperatures and graphene doping amounts with sol-gel process and testing them under the different conditions. Meanwhile, Pd/SnO₂ films by sol-gel method are also prepared and the gas sensitive performance is tested. Finally, the performance test results of the two sensors are analyzed and compared.This thesis optimizes the preparation method of SnO₂ gas-sensing films and the films were characterized by XRD, SEM, AFM, etc. The results of characterization and test show that graphene/SnO₂ materials has the best performance when the sintering temperature is 500?. In is found that the gas sensitive materials can get the better performance when the graphene is doped and ultrasonic dispersed. In addition, it is confirmed that the graphene/SnO₂ materials show the higher sensitivity, better selectivity, better stability and smaller working environment temperature requirements than the Pd/SnO₂ materials by testing the performance of the two materials.