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以二水氯化亚锡(SnCl2·2H2O)为盐原料,采用静电纺丝的方法制备了SnO2纳米纤维.为了研究ZnO掺杂对SnO2形貌、结构及化学成分的影响,分别制备了不同含量ZnO掺杂的SnO2/ZnO复合材料.利用热重-差热分析(TG-DTA)、X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱仪、扫描电镜(SEM)及能量色散X射线(EDX)光谱对材料的结晶学特性及微结构进行了表征.制备的SnO2/ZnO复合材料是由纳米量级的小颗粒构成的分级结构材料.ZnO含量不同,对应的SnO2/ZnO复合材料结构不同.表征结果表明ZnO的掺杂量对SnO2材料的形貌及结构均起着重要作用.将制备的不同ZnO含量的SnO2/ZnO复合材料进行气敏测试,测试结果表明,Sn:Zn摩尔比为1:1制作的气敏元件对甲醇的灵敏度优于其它摩尔比的气敏元件.讨论了SnO2/ZnO复合材料气敏元件的敏感机理.同时针对Sn:Zn摩尔比为1:1时表现出最好的气敏响应,分析了其原因,包括Zn的替位式掺杂行为、ZnO的催化作用、过量ZnO对SnO2生长的抑制作用以及SnO2与ZnO晶粒界面处的异质结.
SnO2 nanofibers were prepared by electrospinning using stannous chloride (SnCl2 · 2H2O) as raw material.The effects of ZnO doping on the morphology, structure and chemical composition of SnO2 were investigated, ZnO doped SnO 2 / ZnO composites were prepared by the methods of TG-DTA, XRD, FTIR, SEM and energy dispersive X-ray diffraction (EDX) spectroscopy was used to characterize the crystallinity and microstructure of the composites.The prepared SnO2 / ZnO composites were graded materials composed of nano-sized small particles with different content of ZnO and the corresponding SnO2 / ZnO composites .The results show that the doping amount of ZnO plays an important role in the morphology and structure of SnO2.The SnO2 / ZnO composites with different ZnO contents were tested for gas sensitivity.The results show that Sn: Zn molar ratio The sensitivity of 1: 1 gas sensor to methanol is better than that of other gas sensors.The sensitivity mechanism of SnO2 / ZnO composite gas sensor is discussed.At the same time, when the Sn: Zn molar ratio is 1: 1, The best gas-sensing response was analyzed for its causes, including Zn Substitutional doping, catalytic effect of ZnO, inhibition of the growth of SnO2 by excess ZnO, and heterojunction at the interface between SnO2 and ZnO.