A way to sense H₂S gas using nanostructured Zinc-Stannate (Zn₂SnO₄) ternary oxide

The sensitive detection of hydrogen sulfide (H₂S) gas has drawn much attention these days for consideration of health concerns. Herein we fabricate Zn₂SnO₄ (ZTO) sensing film by sol–gel spin coating method for low ppm H₂S sensing. A highly crystalline thin film consisting predominantly of Zn₂SnO₄ (98.80 %), with a minor phase of ZnO (1.20 %), features a rough surface characterized by nanorods and hexagonal-shaped nanostructures. These unique morphological features enhance the product's sensing capability. A detailed study of the phase and chemical composition of the final compound was analysed before considering the material for sensing. Post-deposited films demonstrated high selectivity toward H₂S gas over other test gases. In detecting this gas, ZTO exhibited a low response time of 10 s to 7 ppm of H₂S gas at 200 °C operating temperature. A detailed sensing mechanism based on adsorption/desorption mechanism was explained for rapid response of H₂S gas sensing. In addition, the role of intrinsic defects like oxygen vacancy in this activity was also detailed.