Ppb-Level Butanone Sensor Based on ZnO-TiO2-rGO Nanocomposites

In this paper, ZnO-TiO2-rGO nanocomposites were successfully synthesized by the hydrothermal method. The morphology and structure of the synthesized nanomaterials were characterized by SEM, XRD, HRTEM, and XPS. Butanone is a typical ketone product. The vapors are extremely harmful once exposed, triggering skin irritation in mild cases and affecting our breathing in severe cases. In this paper, the gas-sensing properties of TiO2, ZnO, ZnO-TiO2, and ZnO-TiO2-rGO nanomaterials to butanone vapor were studied. The optimum operating temperature of the ZnO-TiO2-rGO sensor is 145 °C, which is substantially lower than the other three sensors. The selectivity for butanone vapor is greatly improved, and the response is 5.6 times higher than that of other organic gases. The lower detection limit to butanone can reach 63 ppb. Therefore, the ZnO-TiO2-rGO sensor demonstrates excellent gas-sensing performance to butanone. Meanwhile, the gas-sensing mechanism of the ZnO-TiO2-rGO sensor to butanone vapor was also analyzed.