Highly sensitive, graphene oxide supported zinc stannate (Zn2SnO4) nanocubes and their room temperature NO2 gas sensor properties

Graphene based hetero-nanostructured sensor systems have gained much attention for improving sensing behavior towards harmful gases, especially NO₂. In this report, enhanced room temperature sensing response towards NO₂ gas using rGO@Zn₂SnO₄ nanocubes. A facile two step synthesis method is adopted involving hydrothermal synthesis for the preparation of highly monodispersed zinc stannate (Zn₂SnO₄) nanocubes having clear edges and length of 80 ± 0.5 nm were found to be anchored on the exfoliated rGO nanosheet supports. X-ray diffraction (XRD) studies divulge the clear existence of crystalline rhombohedral Zn₂SnO₄ and rGO sheets. Gas sensing studies revealed that the Zn₂SnO₄ nanocubes supported on rGO can detect NO₂ even at 30°C and showed enhanced sensing response compared to pristine Zn₂SnO₄ nanocubes based on the spill-over effect and unwrapped rGO sheets.