Preparation of MOF-derived ZnO/Co3O4 nanocages and their sensing performance toward H2S

Han Liu; Jiawei Kong; Zhe Dong; Yongmei Zhao; Baoli An; Junping Dong; Jiaqiang Xu; Xiaohong Wang

doi:10.1039/d3cp02310a

Preparation of MOF-derived ZnO/Co₃O₄ nanocages and their sensing performance toward H₂S

Phys Chem Chem Phys. 2023 Jul 12;25(27):17850-17859. doi: 10.1039/d3cp02310a.

Authors

Han Liu¹, Jiawei Kong¹, Zhe Dong¹, Yongmei Zhao¹, Baoli An¹, Junping Dong¹, Jiaqiang Xu¹, Xiaohong Wang¹

Affiliation

¹ NEST Lab, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.

PMID: 37378864
DOI: 10.1039/d3cp02310a

Abstract

We report a type of micro-electro-mechanical system (MEMS) H₂S gas sensors with excellent sensing performance at the ppb level (lowest detection limit is 5 ppb). The sensors were fabricated with ZnO/Co₃O₄ sensing materials derived from Zn/Co-MOFs by annealing at a suitable temperature of 500 °C. ZnO/Co₃O₄-500 exhibits the highest response when exposed to 10 ppb H₂S gas at 120 °C, and the response/recovery times are 10 s/21 s. Moreover, it exhibits outstanding selectivity, long-term stability (retained 95% response after 45 days), and moisture resistance (only a minor fluctuation of 2% even at 90% RH). This can be ascribed to the fact that ZnO/Co₃O₄-500 has regular morphology, abundant oxygen vacancies (52.8%) and high specific surface area (96.5 m² g^-1). This work provides not only a high performance H₂S MEMS gas sensor but also a systematic study of the effect of the annealing temperature on the sensing performance of ZnO/Co₃O₄ sensing materials derived from bimetal organic frameworks.