▎ 摘　　要

Three-dimensional (3D) reduced graphene oxide (rGO)/cobaltosic oxide (Co3O4) nanocomposites were prepared by a simple and low-cost hydrothermal method. Characterization results confirmed that rGO sheets were selfassembled to form a crosslinked porous network structure and Co3O4 nanoparticles were uniformly attached to the surface of rGO with the specific surface area of 306.49 m(2)/g. More importantly, the as-obtained 3D rGO/Co3O4 nanocomposites exhibited superior gas sensing property for ultra-low concentration detection of triethylamine (TEA) at room temperature; this was because of the mesoporous structure, large specific surface area, and excellent charge carrier transport properties of the nanocomposites. The response value of the 3D rGO/Co3O4 nanocomposite sensors to 1 ppm TEA gas was approximately 35% at room temperature, with extremely fast response and recovery time. 3D rGO/Co3O4 nanocomposites with excellent sensing performance have potential applications in the field of gas sensors.