Metal-Organic-Framework Derived Co-Mo Multimetal Oxide Semiconductors: Selective Trace-Level Hydrogen Sulfide Detection.

The development of a highly selective and trace-level gas sensing platform for detecting hydrogen sulfide (HS) remains a formidable challenge. To solve this problem, Co-Mo multimetal oxide semiconductors are rationally tailored by employing metal organic frameworks (MOFs) as self-sacrificial templates. The MOF-derived CoO/β-CoMoO based gas sensors displays high sensitivity (/ = 22) to 10 ppm of HS and ultralow limit of detection (10 ppb HS). The formation of p-p heterojunction and multivalence states of Mo play a crucial role in electron transfer and oxygen adsorption. A sensor array constructed from four CoO/β-CoMoO materials with different Co/Mo ratios demonstrates a superior selective discrimination of HS from other VOCs and malodorous gases by principal component analysis (PCA). Besides, a HS gas sensing and alarming platform was designed for monitoring the environment contaminated with HS. This finding provides a feasible approach for the discovery of highly efficient gas sensors to monitor environmental HS concentration.