Highly sensitive graphene oxide functionalized ZnO nanowires for ammonia vapour detection at ambient temperature

Abstract

Zinc oxide nanowires were deposited by successive ionic layer adsorption and reaction (SILAR) method on a glass substrate. Graphene oxide powders were electrochemically exfoliated from graphite. The presence of peaks at 20.42°, 22.69°, 25.61° and 43° in the XRD pattern confirms the formation of reduced graphene oxide. Raman peak ratio (ID/IG) was found to be 1.051 for the synthesized powder and it confirms the formation of reduced graphene oxide. Finally, zinc oxide nanowires (ZnO NWs) were successfully functionalized with reduced graphene oxide (rGO). The basic characterization studies such as morphological, structural, and compositional analyses were carried out for rGO/ZnO NWs. It confirmed the formation of ZnO NWs and rGO functionalization over it. The sensing response of ZnO and rGO/ZnO NWs towards the ammonia vapour were studied at ambient temperature (32°C). The obtained results revealed that the sensitivity and selectivity of the ZnO NWs were increased after functionalization. The adsorption mechanism was studied through FTIR and the corresponding results were discussed.