Synergistic integration of hierarchical structure and oxygen vacancy engineering in core-shelled Ni and Zn co-doped Co3O4 microsphere for efficient detection of triethylamine gas

This work presents a hierarchical yolk-shell NiZn-Co₃O₄ sphere with abundant oxygen vacancy by utilizing structure optimization and composition regulation for efficient detection of triethylamine (TEA) gas. A comparative exploration of TEA gas sensing characterization for different Co₃O₄-based sensors is conducted systematically. The result shows that the sensor based on the NiZn–Co₃O₄ HCSS displays the highest sensing response of 42.5 at a working temperature of 180 °C. In particular, the NiZn–Co₃O₄ HCSS device possesses a fast response-recovery speed, excellent anti-humidity and outstanding long-term stability of up to 40 days to TEA gas. The improved TEA gas sensing property can be attributed to the intriguing hierarchical core–shell architecture and abundant oxygen vacancy induced by NiZn co-doping. Moreover, to study the sensing mechanism in detail, the adsorption behavior and charge transfer phenomenon between O_V–NiZn–Co₃O₄ (110) and TEA molecule is carried out by the density functional theory (DFT). This work demonstrates an outstanding performance of Ni and Zn co-doped hierarchical core–shell Co₃O₄ in TEA detection by combining theoretical and experimental investigations into mechanisms for optimized TEA gas molecule sensing.

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