Enhancement of photoresponse and UV-assisted gas sensing with Au decorated ZnO nanofibers

To increase the photoresponsive and gas sensing properties of ZnO nanofibers under UV illumination, Au nanoparticles were introduced to the ZnO nanofibers (Au/ZnO) using electrospinning technique. It is found that adding Au nanoparticles into the ZnO nanofibers enhances significantly the photoresponse and makes the nanofibers also respond to visible light. The gas sensing performance with the assist of UV irradiation at room temperature was also improved greatly, e.g., the sensor response (SR) for 5 ppm ethanol increases from 0.12 to 0.31 by introducing 0.20 mol% of Au in ZnO nanofibers. The improvement of gas sensing performance is attributed to the enhanced photocatalytic reactions of organic gases on the Au/ZnO nanofibers surface. In addition, the sensitive behaviors of the nanofibers to ethanol, benzene, toluene and acetone under UV irradiation with different wavelengths were investigated and compared as well.

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► Au/ZnO nanofiber sensors were successfully prepared using electrospinning.
► The Au/ZnO sensors respond not only to UV light but also to visible light.
► The response to organic analyte at room temperature is also greatly improved.
► Schottky junction between Au and ZnO is one key for the improvement of sensing.