摘要
本文以石墨片作为诱导剂,采用水热法合成了六方相单晶WO_3/C纳米棒材料,同时制备了Ag改性的氧化钨纳米棒和SnO_2(或ZnO)-WO_3/C的复合纳米材料,并对其进行了TG-DTA、XRD、XPS、IR、BET、SEM、TEM等表征,测试了厚膜型器件对乙醇、丙酮、甲醛气体的敏感性能。
纳米棒WO_3/C材料在290℃时对1000μL·L~(-1)的乙醇气体灵敏度为79.3,而其在330℃下对1000μL·L~(-1)丙酮气体灵敏度为32.2。Ag改性的纳米棒材料仍对乙醇和丙酮气体有较好响应,更重要的是降低了测试的工作温度(217和252℃),并提高了对甲醛气体的灵敏度。SnO_2复合WO_3/C材料进一步提高了测试甲醛气体的灵敏度,在252℃时对1000μL·L~(-1)甲醛气体的灵敏度达到9.3,而ZnO复合WO_3/C材料较大提高了对乙醇、丙酮、甲醛气体灵敏度,在330℃时,对1000μL·L~(-1)乙醇和丙酮灵敏度分别为100.0,105.0,对370μL·L~(-1)甲醛灵敏度达到33.4,且三种气体的最低检测限分别为0.1、0.1、0.037μL·L~(-1)。
In this paper, single crystal hexagonal phase of WO_3/C nanorods were synthesized by hydrothermal method with graphite flake as induced agent, which was then used to prepare the Ag modified WO_3 nanorods and SnO_2(or ZnO)-WO_3/C composites. These materials were characterized by TG-DTA, XRD, XPS, IR, BET, SEM and TEM, respectively. Their thick film-type gas sensors were fabricated and their gas sensitivities to ethanol, acetone and formaldehyde were measured.
The sensitivity of WO_3/C nanorods to 1000μL·L~(-1) ethanol is 79.3 at the working temperature of 290℃, while the sensitivity to 1000μL·L~(-1) acetone is 32.2 at the working temperature of 330℃. It is interesting to note that the Ag modified WO_3 nanorods still exhibit good response to ethanol and acetone with lower working temperature (217 and 252℃) and could improve sensitivity to formaldehyde. The SnO_2-WO_3/C composites further improved the sensitivity to formaldehyde, and the sensitivity of the SnO_2-WO_3/C based sensor to 370μL·L~(-1) formaldehyde is 9.3 at 252℃. In comparison, ZnO-WO_3/C composites clearly improved the sensitivity to the gases of ethanol, acetone and formaldehyde. The sensitivities to 1000μL·L~(-1) ethanol and acetone is 100.0 and 105.0 whereas the sensitivity to 370μL·L~(-1) formaldehyde is 33.4. It can detect the gas concentration of the three aforementioned gases as low as 0.1, 0.1 and 0.037μL·L~(-1), respectively.
引文
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