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Zeolitic Imidazolate Framework Coated ZnO Nanorods as Molecular Sieving to Improve Selectivity of Formaldehyde Gas Sensor
journal contribution
posted on 2015-12-22, 00:00 authored by Hailin Tian, Huiqing Fan, Mengmeng Li, Longtao MaZinc 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.