水热法制备三维花状WO_3基甲醛气敏材料

Preparation of 3D Nanoflower WO_3 via Hydrothermal Method for Detecting Formaldehyde

本文采用水热法成功制备了纳米花状WO_3,用于在低温工作环境下甲醛气体的高效检测。利用X射线衍射仪(XRD)和场发射扫描电子显微镜(SEM)对产物的晶体结构及微观形貌进行表征。XRD分析表明,前驱体为单斜晶系结构WO_3和正交晶系结构WO_3·0.33H_2O混合晶相,通过在450℃煅烧2h得到了单斜晶系结构WO_3。气敏测试结果表明,煅烧后的WO_3制成的气敏元件对100ppm甲醛的响应/恢复时间为5s/15s,响应值是R_a/R_g=16.5,最佳工作温度为300℃。对气敏元件表面可能发生的氧化还原反应的机理也进行了研究和讨论,认为WO_3是一种很有前景的有机污染物气敏传感材料。

In this paper, 3D nanoflower WO3 was successfully prepared by hydrothermal method, which was used to detect formaldehyde gas effectively in low temperature working environment. The crystal structure and microstructure of the product were characterized by X ray diffractometer （XRD） and field emission scanning electron microscope （SEM）. XRD results showed that the precursor was the mixture of monoclinic structure WO3 and the orthogonal structure WO3.0.33H2O, whereas monoclinic structure WO3 were obtained by calcining at 450℃ for 2 h. Gas sensing texts showed that the sensors fabricated by cal cined WO3 exhibited a quick response（5 s）/recovery（15 s） rate to 100 ppm HCHO, and the response value Ra/Rg was 1G. 5 at the optimum temperature of 300℃. The possible oxidation reduction reaction mecha nism of HCHO molecule on the sensor surface were researched and discussed too, WO3 was considered to be a promising sensing materials for detecting organic pollutants.