Study On The Preparation And Gas Sensing Properties Of Fluorinated Graphene/Zinc Oxide Composites

This dissertation focused on the synthesis of fluorinated graphene for gas-sensing applications,with fluorinated graphite as the raw material via Hummers method.The flowerlike Zinc Oxide was prepared by sonication-assisted hydrothermal.And the synthesis of fluorinated graphene/Zinc Oxide composites by hydrothermal method was studied.Analysis by means of X ray diffraction spectrum(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman spectroscopy,infrared spectroscopy of Fu Liye(FTIR),UV Vis absorption(UV-vis),specific surface area(BET),thermogravimetric analysis(TGA-DSC)etc..The structure,functional groups,micro morphology and thermal stability of the three materials were studied.Result specification: The oxygen containing functional groups were prepared by the improved Hummers method,and the oxygen-containing functional groups were mainly in the form of C=O,S-O and epoxy,and the content of F element in the fluoride was 18.42%.The fluorine fossil is stable before 200?,and the loss of C-F and C-C occurs after 200?.The sensitivity of the fluorinated fossil to the gas is that the fluorinated graphene has the highest sensitivity to ammonia,and the response time is longer than that of 27 s.According to the determination of the optimum operating temperature of the gas sensitive characteristics of the fluorine fossil,the best working temperature of the fluorinated olefin was 150?.Using zinc acetate and urea as reactants,Zinc Oxide was prepared by ultrasonic hydrothermal method.When the concentration of Zn2+ ion was 1.0mol/L,the concentration of OH-ion was 0.75mol/L,the ultrasonic time was 20 min,the morphology of flower Zinc Oxide was the best when the hydrothermal condition was 10 h and 180?.The gas sensitivity test shows that the flower like Zinc Oxide,the Zinc Oxide morphology of ethanol,ammonia,methane,formaldehyde has a better response value,the ammonia sensitivity is the highest(59.23%),and also the shortest response time(37s).The results of different concentrations of ammonia test show that the Zinc Oxide with different concentration of ammonia has different response value,which can better reflect the change trend of ammonia concentration.The fluorinated graphene/Zinc Oxide composites were prepared by hydrothermal method.SEM,XRD and TG were used to analyze the morphology of the fluorine and Zinc Oxide,which is flower morphology.The gas sensitivity test shows that the gas sensitivity of the composite is higher than that of the fluorine fossil,and the optimum operating temperature is 135?.