In-situ MOF-derived strategy for fabricating Cu-doped Zn2SnO4 based H2S gas sensors with ultra-low detection limits

Hydrogen sulfide (H 2 S), emerges as a toxic gas that poses significant threats to human life and health, even at low concentrations (100 ppb). Therefore, the detection and monitoring of H 2 S are crucial for ensuring mining safety. Herein, zinc stannate (Zn 2 SnO 4 , ZTO) was synthesized using hydrothermal method, and copper-doped zinc stannate material (xCuZ) were synthesized by in-situ derivation of metal organic frameworks (MOFs). A ppb-level H 2 S gas sensor with rapid response and recovery was developed. The material with a Cu addition of 20 wt% (20CuZ) exhibited the optimal performance, with a sensitivity of 8 to 10 ppm H 2 S at 275 °C, which was approximately 8 times higher than that of pure ZTO, and surprisingly, exhibited high signal-to-noise ratio and rapid response and recovery characteristics (21 s/27 s) at ultra-low concentrations of 10 ppb. The improvement in gas sensing performance can be primarily attributed to the significant adsorption capability of Cu for H 2 S. Furthermore, the incorporation of Cu into the ZTO material induces lattice defects and increases the concentration of oxygen vacancies, thereby enhancing the gas sensing performance. The sensor produced in this study has the potential to mitigate the risks with mining operations while advancing the development of gas sensor technology.