Indium-doped SnO2nanoparticle–graphene nanohybrids: simple one-pot synthesis and their selective detection of NO2

Abstract

We demonstrate novel nanohybrids of indium- and ruthenium-doped SnO₂ nanoparticles (NPs) on a reduced graphene oxide (RGO) surface prepared using a simple one-pot method at a relatively low temperature. The size of the doped SnO₂ NPs on the RGO is as small as 2–3 nm with uniform distribution. We find that the introduction of dopants facilitates the NP nucleation on graphene oxide. The gas sensing responses of the resulting nanohybrids demonstrate that the addition of indium in SnO₂ significantly enhances the sensitivity to NO₂ compared with RGO–SnO₂. The sensor also shows excellent selectivity to NO₂ when other common gases such as NH₃, H₂, CO and H₂S, are present. The sensing mechanism responsible for the superior sensitivity and selectivity of the nanohybrids is also discussed.