Enhancing Hydrogen Sulfide Gas Detection: Tailoring ZnO Films Through a Novel Sol–Gel Approach with Ultra-Sonication

In this study, nano-sized Zinc Oxide (ZnO) particles were synthesized using a novel sol–gel process with Zn(NO₃)₂ solutions, specifically tailored for the development of a highly efficient Hydrogen Sulphide (H₂S) gas sensing element. The impact of ultra-sonication on the properties crucial for H₂S detection was systematically investigated. The resulting ZnO materials exhibited a well-defined crystalline structure along (100), (002), (101), and (102) planes, confirming the formation of the hexagonal wurtzite phase of ZnO. Significantly, an increase in sonication treatment time led to a reduction in particle size. The gas sensing properties for H₂S were meticulously analyzed in relation to the varying sizes of ZnO films. Remarkably, the ZnO film fabricated with a 30-minute ultra-sonication treatment demonstrated the highest response to H₂S gas at 423 K. The ZnO-thick films exhibited notable sensitivity, coupled with rapid reactivity and recovery times upon exposure to H₂S gas. Importantly, our findings establish a direct correlation between the sensitivity of the ZnO sensor and the particle size.