▎ 摘　　要

A novel macroporous microrecycled ZnO nanoparticles (NPs) recovered from spent Zn-C battery decorated three-dimensional (3D) graphene aemgel hybrid materials has been synthesized via simple eco-friendly synthetic method. The 3D graphene aemgel demonstrate interconnected macropomus networks and the microrecycled ZnO NPs displayed a size of similar to 40 nm are attached uniformly on the surface of graphene flakes. When being used as NO2 sensors for detecting low concentration of NO2 gas molecules, this macroporous 3D hybrid structure achieved a higher response value along fast response-recovery time characteristics with superior selectivity and repeatability behaviour at room temperature (RT, 20 degrees C). The elevated NO2 sensing properties for this 3D structure is mainly associated with improved conductivity and porous structure of graphene as well as the interaction between p-type graphene and n-type zinc oxide. Along with the representation of elevated NO2 sensing performance, mechanism behind this sensing phenomenon also discussed in this study. These results and the low-cost, light-weight and eco-friendly fabrication features indicate that the proposed microrecycled ZnO NPs decorated 3D graphene aerogel hybrid sensor is a promising building block for the advancement of high-performance NO2 sensors for real field applications.