Fabrication of ZnO@ZIF-8 gas sensors for selective gas detection

In this paper, zinc oxide nanorods encapsulated with a representative of the zeolithic imodazole based metal organic framework family (ZIF-8) is used as gas sensor material for the detection of hydrogen gas and benzene vapour. The material properties of this ZnO@ZIF-8 hybrid material was investigated by XRD, electron microscopy, Fourier transform infrared spectroscopy and gas sensing experiments. Selectivity and sensitivity of these thin films to various gases H-2 and C6H6 were also studied. The ZnO@ZIF-8 sensor with the nanostructure showed a remarkable selective response to hydrogen gas as compared to the pristine ZnO nanorods sensor, while the ZnO sensor shows high sensitivity to H-2 and C6H6. The ZnO@ZIF-8 sensor exhibits a significant selective response to hydrogen compared to the original ZnO nanorod sensor. This behavior can be attributed to the small pore aperture of ZIF-8, where H-2 molecules it can easily spread through the ZIF-8 network and reach the ZnO surface. This result indicate that the selectivity of ZnO gas sensor can be regulated by surface ZIF-8 coating.