The Study Of Biological Form Tin Oxide Gas-sensing Materials To Preparation By Template

With the development of society and the improvement of people environmental protection consciousness,people is more and more attention on all kinds of poisonous and harmful,flammable and explosive gas detection.As acore component of gas-sensitive detection device,the development and study of gas sensitive materials attracted much attention.Current researches shows that the gas-sensing properties have a direct correlation with the microstructure and composition of materials,the hierarchical porous structuresare excellent structural candidatesgas sensing materials,doping modification is an effective method to improve the performance of gas sensor.Weexplored from the perspective of structure and optimization design of components,using biological templates prepared tin oxide forms of porous ceramics,and component optimizationthrough the rare earth doping,analysis of the preparation of material microstructure and doping modification on the properties of gas sensitive effect and the mechanism of action.The main contents and results are as follows:Coconut shell and Walnut shell chosen as the template,using biological templates prepared the biological form tin oxide gas-sensing materials,the preparation of the biological form of its physical and chemical properties,characterizing the morphology and composition,studied the template mould modification,concentration of liquid precursor preparation and sintering temperature on the influence of material microstructure and gas sensitiveperformance.Results showed that the degumming alkali treatment can improve the impregnation rate and gas sensitive properties.The specific surface area and gas sensitive properties with the increase of the soaking liquid concentration is on the decline.Aerobic sintering temperature is a parabola vertices,coconut shell template to 850 ?C,Walnut shell template to 700?C,higher than the temperature of sintering material skeleton template structure started to collapse,loose porous destroyed and materials of gas sensitivity.In preparation on the basis of structure design and optimization of process parameters of synthesis of the Ce doping coconut shell morphology tin oxide based gas sensitive material and La doping Walnut shell morphology of tin oxide gas sensitive material,XRD,SEM,EDS and BET to characterization,to study the contents of the Ce doping and aerobic sintering temperature on the microstructure and gas sensitive material performance and the influence of the sensitive mechanism.Results show that the Ce doping on the coconut shelland particle morphology of tin oxide grain grew up together since inhibition,enhance the material on the sensitivity of the acetone,the acetone has good selectivity,reduces the best working temperature.La doping Walnut shell morphology tin oxide gas-sensing materials for ethanol has a good sensitivity,selectivity,low working temperature and good stability.