One-pot synthesis of core–shell ZIF-8@ZnO porous nanospheres with improved ethanol gas sensing

• Published in: Journal of materials science. Materials in electronics 2020-12, Vol.31 (24), p.22534-22545
• Main Authors: Feng, Shaopei, Jia, Xiaohua, Yang, Jin, Li, Yong, Wang, Sizhe, Song, Haojie
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Core-shell structure; Ethanol; Gas sensors; Homology; Hydrothermal reactions; Materials Science; Metal oxides; Morphology; Nanospheres; Operating temperature; Optical and Electronic Materials; Selectivity; Sensitivity; Structural analysis; VOCs; Volatile organic compounds; Zeolites; Zinc oxide; Zinc salts
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-04764-y

Rational design and synthesis of hollow core–shell hetero-structures with high complexity still remains challenging for high gas-sensing performances. Here, ZIF-8@ZnO (zeolite imidazolate framework-8) core–shell material was synthesized using an easy-to-use hydrothermal reaction. ZnO is a kind of homologous metal oxide of ZIF-8 material. Therefore, without adding other zinc salts, the formation of ZIF-8@ZnO was completed in a one-pot reaction. Then a series of morphology and structure analysis including XRD, BET, SEM, EDX, etc. were carried out to study the positive effect of ZIF-8 film on the sensing performance of ZnO nanospheres. The results show that the ZIF-8 film uniformly covers the surface of porous ZnO nanospheres with a diameter of about 400 nm, forming a core–shell structure. Compared to the other volatile organic compounds (VOCs), ZIF-8@ZnO shows a higher sensitivity and selectivity to 50 ppm ethanol gas at an operating temperature of 220 °C, which can achieve 13.8. This is almost 2.7 times that of pure ZnO nanospheres (5.1). The obtained results show that ZIF-8@ZnO core–shell material not only greatly improves the sensitivity of the sensor, but also enhance the selectivity of ethanol gas sensing.