Room Temperature NO2 Responses of Visible-Light Activated Nanosheet rGO@ZnO1−x Sensors

In this study, we use a facile hydrothermal method to synthesize rGO@ZnO1−x composites. The in-situ synthesized ZnO nanosheets are well attached on the rGO sheets, which prevent the aggregation and restacking of ZnO nanosheets, greatly increasing the specific surface area of the synthesized materials. In addition, on account of the reducing synthesis condition, large numbers of oxygen vacancies are implanted into ZnO. With the incorporation of rGO, the visible light absorption range of the composites is greatly enhanced. The synthesized rGO@ZnO1−x composites exhibit excellent performance to ppb-level NO2 under white light illumination at room temperature, which effectively overcomes the disadvantages of typical metal oxide gas sensors.