CuO-sensitized amorphous ZnSnO3 hollow-rounded cubes for highly sensitive and selective H2S gas sensors

Hydrogen sulfide (H2S), a toxic and flammable gas, poses a substantial threat to human health and the ambient environment. Therefore, producing responsive H2S sensors that have excellent selectivity and work at low temperatures has been a goal for researchers. In this study, hollow-rounded cubes composed of copper oxide (CuO)-sensitized amorphous zinc stannate (zinc tin oxide (ZTO)) were prepared by a coprecipitation method combined with an impregnation treatment. Various characterization methods are employed to analyze the crystal phase, morphology, and composition of the synthetic materials. The results showed that the materials were composed of hollow, rounded, amorphous cubes with a 500–700 nm uniform particle size. The as-prepared materials were applied to gas sensors, and their H2S-sensing performance was systematically tested. Compared with the ZTO- and CuO-based sensors, the CuO/ZTO-based sensor exhibited excellent gas-sensing performance toward H2S, with a maximum response value of 574–10 ppm H2S and a low operating temperature of 160 °C. In addition, the sensor showed higher selectivity and a low detection limit of 200 ppb. The findings indicate that the CuO/ZTO composite is promising as an H2S-sensing material with potential applications in the field of environmental air monitoring. •Amorphous CuO/ZTO hollow-rounded cubes were prepared by coprecipitation and subsequent impregnation treatment.•The CuO/ZTO-based sensor exhibited excellent gas-sensing performance toward H2S at a low operating temperature of 160 °C.•The CuO/ZTO-based sensor showed higher selectivity and a low detection limit of 200 ppb.•The conversion of CuO to CuS and the construction of heterojunctions between CuO and ZTO improved the sensing performance.