Gas sensor based on rGO/ZnO aerogel for efficient detection of NO2 at room temperature

In this paper, a simple, low cost and easy to operate hydrothermal method was successfully used to synthesize rGO/ZnO aerogel in one step. Then the obtained sample is prepared into a sensor to test its sensing performance against NO2. The prepared material is characterized in a series of ways. The SEM and TEM results also show that the rGO/ZnO aerogel after freeze-drying is a regular cylinder with a large pore network structure with cross-linking inside, and ZnO is uniformly distributed on the surface of the rGO sheet layer. To further confirm that the pore structure inside the aerogel increased the specific surface area, the samples were characterized by BET, and the specific surface area of aerogel was 108.79 m2/g. These results indicate that rGO/ZnO aerogel has a large surface area, which enhances the active sites at the surface/interface and makes it a promising gas sensing material. The results showed that the rGO/ZnO aerogel had a NO2 response of 13% to 20 ppm at room temperature. And has a good response recovery, reproducibility is good. This is mainly due to the rapid charge transfer rate of the heterogeneous interface of the composite. rGO/ZnO aerogel has a potential application prospect in gas sensor field due to its simple and easy preparation method and excellent performance at room temperature.