Novel SnO2@open microcell-liked graphene network as efficient detection for NO2

The design of reduced graphene oxide (RGO) with novel porous structure has attracted tremendous attention owing to their larger specific surface area. Herein, three-dimensional open microcells, bowl-shaped RGO were fabricated through spray drying method which employed polystyrene spheres as a sacrificial template. The bowl-shaped, open microcell-liked pores observed in the RGO network had an average diameter of ≈1 μm. Subsequently, the catalytic SnO2 nanoparticles were loaded on RGO network via a simple solvothermal method (SnO2@RGO), and their gas sensing properties were investigated at room temperature (RT). In a comparison with pristine RGO network, the SnO2@RGO composite exhibited almost 4 times higher response to 400 ppm NO2 at RT and rapid recovery time. The extraordinary sensing performance can be attributed to the novel open microcell-liked porous microstructure with the SnO2 catalyst nanoparticles.