Room-temperature ammonia gas sensor based on reduced graphene oxide nanocomposites decorated by Ag, Au and Pt nanoparticles

We report a novel and highly sensitive two-dimensional (2D) gas sensing material based on metal nanoparticles-reduced graphene oxide (rGO) nanocomposite for the detection of ammonia gas. The rGO samples decorated by Ag, Au and Pt nanoparticles (NPs) were successfully synthesized using a singlestep chemical reduction process, and the effect of different metal NPs on the gas sensing performance for ammonia gas were systematically investigated. The samples were characterized by TEM and XRD methods. The gas-sensing properties of the fabricated sensors were investigated for NH3 and other target gases at room temperature. The sensor decorated by AgNPs has higher sensitivity, selectivity, better response/recovery times and great stability to ammonia gas than sensors decorated by Au and Pt NPs. AgNPs-rGO presented the highest performance, confirming a strong dependence on the metal type. The enhanced sensing properties of the samples may be attributed to the combined effect of the superior conductivity of rGO and metal nanoparticles, chemical sensitization caused from proposed production method, catalytic properties of metal nanoparticles and active oxygen species on the rGO surface. (C) 2017 Elsevier B.V. All rights reserved.