Sensing properties of SnO₂-Based Thin-Film Sensors for the Detection of H₂S

In this study, we fabricated a novel recoverable tin oxide (SnO₂) thin-film gas sensor for the detection of hydrogen sulfide (H₂S) using an ion sputtering technique. The SnO₂ thin film consisted of uniform clusters with a size of approximately 50-80 nm. The thickness of the SnO₂ film was approximately 100 nm, and the size of the nanorod type was approximately 50-100 nm. In addition, we confirmed that the SnO₂ thin-film sensor showed a SnO₂ phase with a tetragonal structure. The SnO₂ thin-film gas sensor showed not only an excellent sensor response of 86% for detecting 1 ppm H₂S in a flow system, but also complete recovery under air at 400 °C without a promoter, unlike the SnO₂ thick-film sensor, which can realize recovery by promoting with metal oxides such as MoO₃ and CuO. In particular, the SnO₂ thin-film gas sensor showed a high sensor response of approximately 60% for detecting very low concentrations of 0.25 ppm H₂S at 400 °C.