3D graphene aerogel-supported SnO2 nanoparticles for efficient detection of NO2

Three-dimensional (3D) graphene aerogel-supported SnO2 (SGA) nanoparticles (NPs) are presented by a one-pot solvothermal treatment of graphene oxide in the presence of SnCl4 followed by freeze drying. The size of SnO2 nanoparticles on the graphene aerogel is as small as 5–10 nm with uniform distribution. The 3D SnO2–graphene aerogel exhibits interconnected macroporous networks which will be beneficial for gas detection. The SGA shows excellent response and selectivity towards NO2 when other common gases are present at room temperature (RT). The gas sensing responses of the resulting nanocomposites demonstrate that macroporosity in the SGA significantly improves the response and recovery time compared with the 2D SnO2–graphene nanocomposite. The sensing mechanism and the reasons for the better response are also discussed.