Gold functionalized ZnO nanowires as a fast response/recovery ammonia sensor

Abstract

ZnO nanowires (NWs) were functionalized with Au nanoparticles through thermal evaporation method. The sensing performance of the Au functionalized ZnO NWs (Au/ZnO NWs) towards reducing vapours at ambient temperature (∼32 °C) were studied and compared with the ZnO NWs. Au/ZnO NWs shows comparatively lesser response time (ZnO = 66 s and Au/ZnO = 8 s) and recovery time (ZnO = 38 s and Au/ZnO = 36 s) than that of bare ZnO NWs. The catalytic activity of the Au nanoparticles significantly reduces the response time during the detection of ammonia vapour. For Au/ZnO NWs, the ammonia response was found to be increased, whereas the response to other vapours was decreased. Au/ZnO NWs shows the linearity between response and concentration (adj R2 = 0.976), hence it can be utilized for the quantitative analysis.