贯通有序大孔SnO2气敏材料的制备及气敏性能

Preparation of interconnected ordered macroporous SnO_2 gas-sensing material with enhanced gas-sensing properties

以聚苯乙烯(PS)微球为模板,氧化锡(SnO_2)纳米晶为骨架,采用颗粒模板法成功制备了贯通有序大孔SnO_2气敏材料。改变PS微球的粒径,可以调节大孔SnO_2气敏材料的大孔孔径,本文以平均粒径约284nm和356nm的PS微球制备了大孔孔径分别约为200nm和260nm的贯通有序大孔SnO_2气敏材料。对制备的样品进行了热重、X射线衍射、扫描电子显微镜和氮气吸附脱附分析。结果表明:大孔排列高度有序,孔道贯通,孔壁由SnO_2纳米晶构成。制备的大孔SnO_2气敏材料不仅具备大孔-介孔-微孔结构,而且具有大的比表面积,具备优异的气敏性能。气敏测试结果表明孔径为200nm和260nm的贯通有序大孔SnO_2在280℃的工作温度下对300μL/L的乙醇气体的灵敏度为145、245,分别是无大孔SnO_2纳米晶的2.2倍、3.7倍。

Interconnected ordered macroporous SnO2 were prepared via template method by utilizing polystyrene（PS）microspheres as template and SnO2 nanocrystals as framework. The pore size of the macropores can be controlled by changing the diameter of PS microspheres. Macroporous SnO2 with average pore sizes of 200 nm and 260 nm were prepared via PS microspheres with the diameters of 284 nm and 356 nm,respectively. The as-prepared samples were characterized by thermogravimetric analysis,scanning electron microscope（SEM）,X-ray diffraction（XRD）,and Nitrogen adsorption-desorption analysis. The as-prepared samples are consist of ordered macropores,interconnected nanopores,and SnO2 nanocrystals. The as-prepared sample possess macro-/meso-/micro-structure with large surface area,which is beneficial for gas-sensing. The responses of macroporous SnO2 with average pore size of 200 nm and 260 nm towards 300μL/L ethanol vapor at 280℃ are 145 and 245 respectively,which are 2.2 and 3.7 times higher than that of SnO2 nanocrystals.