介孔结构CeO_(2)对丙酮的敏感响应研究

Study on the sensitive response of mesoporous CeO_2 to acetone

采用水热法一步合成制备了一种多面体介孔结构CeO_(2),并用于有机挥发性气体的检测。利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察形貌、尺寸和结构,X射线衍射(XRD)、拉曼光谱(Raman)和X射线光电子能谱(XPS)分析其晶体结构和化学成分,利用全自动气体吸附分析仪分析其孔径大小。结果表明:制备的CeO_(2)为多面体介孔结构,孔隙主要孔径小于4 nm。CeO_(2)传感器在240℃时响应最佳,对100 cm3/m3甲醇、甲醛、乙醇、乙醚、丙酮、乙二醇和二甲苯等气体的检测中,丙酮气体的响应值最高为550%,其对应的响应和恢复时间分别为16 s和4 s。该传感器在60 d内具有较高的稳定性,相对标准偏差值(RSD)为2.0%。

A polyhedral mesoporous CeO_2 was prepared by facile hydrothermal method and used for the detection of organic volatile gases.The morphology,particle size and structure were observed by scanning electron microscope(SEM)and transmission electron microscope(TEM),the crystal structure and chemical composition were analyzed by X-ray diffraction(XRD),Raman spectroscopy(Raman)and X-ray photoelectron spectroscopy(XPS),and the pore size was measured by automatic gas adsorption analyzer.The results showed that the prepared CeO_2 possesses polyhedral mesoporous structure,and the main pore size was less than 4 nm.The mesoporous CeO_2 sensor has an optimal response to acetone at 240℃,which is 550%to that of methanol,formaldehyde,ethanol,ether,acetone,ethylene glycol and xylene gases with the concentration of 100 cm~3/m~3.The corresponding response time and recovery time were 16 s and 4 s for 100 cm~3/m~3 acetone detection,respectively.The sensor has high stability in 60 d with the relative standard deviation(RSD)of 2.0%.