Font Size: a A A

The Research On SnO2 Gas Sensor

Posted on:2007-01-15Degree:MasterType:Thesis
Country:ChinaCandidate:C ChenFull Text:PDF
GTID:2178360212483806Subject:Materials science
Abstract/Summary:PDF Full Text Request
Nanometer SnO2 powders were prepared by hydrothermal synthesis method. Methane gas sensor was fabricated with the powders and doped with Pd, Sb, Y on the base of the sensor. Hydrogen gas sensor was fabricated with the powders and doped with Ag, Al, Bi on the base of the sensor. The surface active material was composed of Al2O3 and Pt. Then the surface catalyst layer was fabricated with the materials by the surface catalyzing. Gas-sensing characteristics were tested in the different gas, such as methane, hydrogen and ethanol. The result was studied.The Nanometer SnO2 powders were studied by SEM and X-ray diffraction instrument. Through the SEM photograph and XRD pattern, we can study the effect of chemical dynamic condition on the SnO2 crystallite. The optimum temperature, time and pH value were 160℃,12h and 1.5.The effect of some catalysts on the thick film gas sensors was studied .We can find after we added Sb3+ ions to the hydrothermal SnO2 crystallite, Sb3+ and Sb5+ exist on the SnO2 crystallite. The shape had an effect on the SnO2 crystallite structure, initialized resistance value and gas-sensing characteristics. After Pd catalyst was heat treatment, nanometer PdO1-x dispersed in the surface of nanostructure thick film material. Spillover effect was investigated. Ag+ can exist on the surface of SnO2 crystallite and substitute the Sn4+. The result was researched. In addition to that, the function of Y, Al, Bi had been studied.The gas sensor with coating of Al2O3 and H2PtCl ? 6H2O has high selectivity to interfered gas. Through the SEM photograph, we found the SnO2 crystallite grain was like the puncheon and a porous net microstructure was formed. Then, we deduced the reaction process of different gas.Improving the selectivity of hydrogen gas sensor to ethanol is the difficult problem .It will be focused on studying in the future.
Keywords/Search Tags:Hydrothermal synthesis, Doping, Gas-sensing characteristics, Surface catalyzing
PDF Full Text Request
Related items