溶胶-凝胶法制备WO_3-SiO_2材料的氨敏特性研究

Study on NH3 Sensing Properties of WO3SiO2 Materials Prepared by Solgel Method

采用溶胶－凝胶法制备了ＷＯ３＋ｘｗｔ％ＳｉＯ２（ｘ＝０，５，１０，２０）粉体材料。对其结构、形貌进行了ＸＲＤ、ＡＦＭ、ＸＰＳ和比表面积测量、分析，结果表明：获得了单斜晶系结构的ＷＯ３多晶材料；晶粒尺寸随ＳｉＯ２含量的增加而减小。测量了材料的ＮＨ３气敏特性，得到敏感元件的电阻和灵敏度随ＳｉＯ２含量的增加而增加；溶胶－凝胶法制备的ＷＯ３＋５ｗｔ％ＳｉＯ２粉料用于ＮＨ３测量具有优良的特性，在３５０℃及以上应用优于纯ＷＯ３材料。

Gas sensing materials of WO3+xwt%SiO2 (x=0,5,10,20) were prepared by means of solgel method. The microstructure was characterized through XRD, AFM, XPS and surface area analyzer. It was observed that the nanosized monoclinic phase of WO3 was formed and the grain size decreased with increasing amount of SiO2. The materials' NH3 sensing properties were measured in the conventional flow apparatus. Being superior to pure WO3 element the WO3+5wt%SiO2 sensing element gave fairly good response to NH3 above 350℃.