Novel 3D graphene aerogel–ZnO composites as efficient detection for NO2 at room temperature

A novel three-dimensional graphene aerogel–ZnO spheres composite has been synthesized via a simple solvothermal method. The three-dimensional graphene exhibits interconnected macroporous networks and the ZnO spheres featured a size of 0.5–1 μm are anchored homogeneously on the surface of graphene layers. When being used as gas sensors for detection of NO2, the porous graphene–ZnO composite achieves a higher response and fast response/recovery behavior at room temperature effectively (RT). The enhancement of the sensing response is mainly attributed to the improved conductivity, the 3D porous structure of graphene and the interaction between p-type graphene and n-type zinc oxide. The sensing mechanism of the composite is also discussed.