Citation: HU Ming-Jiang, LYU Chun-Wang, YANG Shi-Bin, WANG Zhong. Research on Cataluminescence Type Formaldehyde Sensor Based on CeO2-Co3O4 Nanofibers. Chinese Journal of Analytical Chemistry, 2017, 45(11): 1621-1627. doi: 10.11895/j.issn.0253-3820.170221 [复制]
Research on Cataluminescence Type Formaldehyde Sensor Based on CeO2-Co3O4 Nanofibers
采用双喷嘴静电纺丝法制备了CeO2-Co3O4纳米纤维，将制备的CeO2-Co3O4纳米纤维均匀涂覆于μ型加热线圈表面形成催化发光薄膜，设计了一种新型催化发光甲醛传感器。采用X射线衍射仪、扫描电子显微镜、全自动程序化学吸附仪和X-射线光电子能谱仪，表征了Co3O4-CeO2纳米纤维的相组成和微观形貌，讨论了甲醛在CeO2-Co3O4催化剂表面的电化学特性和催化发光机理。在优化条件下，即波长500 nm、温度550℃、载气流速0.2 L/min，甲醛传感器件（Ce30）催化发光强度与甲醛浓度在1.2-50μg/m3范围内有良好的线性关系，灵敏度为40.04 a.u./（μg/m3），检出限为1.2μg/m3，动态响应和恢复时间分别为2.4和3.5 s。此传感器可用于汽车尾气中甲醛浓度检测，相对误差范围为0.4%-1.1%，相对标准偏差RSD < 3%（n=6）。
CeO2-Co3O4 composite nanofibers were prepared by the double jets electrospinning method. The nanofibers were then deposited onto the surface of a μ-type heating coil as cataluminescence material to prepare a new cataluminescence (CTL) type formaldehyde gas sensor. The crystalline phase and microstructure of CeO2-Co3O4 composite nanofibers were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the cataluminescence mechanism and electrochemical characteristic of formaldehyde on the surface of CeO2-Co3O4 nanofibers were analyzed by H2 temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). Under the optimal conditions (500 nm of wavelength, 0.2 L/min of flow rate and 550℃), there was a good relationship between the CTL intensity of this formaldehyde gas sensor (Ce30) and formaldehyde concentration in the range of 1.2-50 μg/m3, the sensitivity was 40.04 a.u./(μg/m3), the detection limit was 1.2 μg/m3, the dynamic response time and recover time of formaldehyde gas were 2.4 s and 3.5 s, respectively. The formaldehyde sensor was successfully applied to the determination of formaldehyde in the automotive exhaust, with relative errors of 0.39%-1.07% and relative standard deviations of less than 3%.