The Craft Study And Performance Analysis Of Superficial Ornamenting SnO₂ Gas Sensors

SnO₂ is an important raw material of chemical industry and ceramics. SnO₂ gas sensitive material is the key point of ceramics semiconductor gas sensitive material study and the major material in industry currently. But it exists problems such as selectivity and stability...etc. and many technique problems need a further research.The SnO₂ nanometer powders were produced by using Sol-gel method and semipermeable membrane dialysis technology. The SnO₂ gas sensors,Al₂O₃ catalyzing layer ornamenting SnO₂ double membrane gas sensors and TiO₂ catalyzing layer ornamenting SnO₂ double membrane gas sensors were produced by using heater-type structure.By using the static distribution gas method, the test result indicates that the SnO₂ gas sensor is more sensitive to ethanol, the highest sensitivity can reach to more than 12, while it has no sensitivity to methane. It can be made into gas sensitive component for testing ethanol gas. Al₂O₃ catalyzing layer ornamenting SnO₂ double membrane gas sensor is more sensitive to methane when the mass fraction of Pt is 3%, the highest sensitivity can reach to more than 5, while it is not sensitive to ethanol. It can be made into gas sensitive component for testing methane. Through researching the affection of heating voltage to the sensitivity, we discover that the component has best selectivity to methane when the heating voltage is 5V, is about 5.TiO₂ catalyzing layer ornamenting SnO₂ double membrane gas sensor is the most sensitivity to methane when the mass fraction of Pt is 7%, the highest sensitivity can reach to more than 5,and the sensitivity to ethanol is about 2. Its selectivity is less than Al₂O₃ catalyzing layer ornamenting SnO₂ double membrane gas sensor.The surface topography of Al₂O₃ (mixed 3%Pt) catalyzing layer ornamenting SnO₂ double membrane gas sensor was observed by SEM. The test...