Zeolitic Imidazolate Framework Coated ZnO Nanorods as Molecular Sieving to Improve Selectivity of Formaldehyde Gas Sensor

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• 作者：Hailin Tian ; Huiqing Fan ; Mengmeng Li ; Longtao Ma
• 刊名：ACS Sensor
• 出版年：2016
• 出版时间：March 25, 2016
• 年：2016
• 卷：1
• 期：3
• 页码：243-250
• 全文大小：782K
• ISSN：2379-3694

文摘

Zinc oxide (ZnO) and zeolitic imidazolate framework-8 (ZIF–8) core–shell heterostructures were obtained by using the self-template strategy where ZnO nanorods not only act as the template, but also provide Zn²⁺ ions for the formation of ZIF–8 shell. The ZIF–8 shell was uniformly deposited to form ZnO@ZIF–8 nanorods with core–shell heterostructures at 70 °C for 24 h as the optimum reaction time by the hydrothermal synthesis. Transmission electron microscopy (TEM) images revealed that the ZnO@ZIF–8 heterostructures are composed of ZnO as core and ZIF–8 as shell. Nitrogen (N₂) sorption isotherms demonstrated that the as-prepared ZnO@ZIF–8 nanorods are a typical microporous material. Additionally, the ZnO@ZIF–8 nanorods sensor exhibited distinct gas response for reducing gases with different molecule sizes. The selectivity of the ZnO@ZIF–8 nanorods sensor was obviously improved for the detection of formaldehyde owing to the limitation effect of the aperture of ZIF–8 shell. This study demonstrated that semiconductor@MOF core–shell heterostructures may be a novel way to enhance the selectivity of the gas sensing materials.