Preparation and characterization of silver film coated ZnO nanowire gas sensors based on the infrared surface enhancement effect for detection of VOCs

Abstract

To increase the sensitivity for detection of volatile organic compounds (VOCs), a ZnO nanowire surface coated with a Ag film by a two step growth method has been proposed. At first, the ZnO nanowire surface was activated using a sensitizer in order to coat it with a Ag film using a silver plating solution and the effect of this has been studied systematically. The results revealed that the enhanced IR intensities of the adsorbed molecule were observed and the surface enhancement effect on the Ag film coated ZnO nanowires can be utilized for the detection of VOCs by ATR-FTIR. In this method of preparing Ag film coated ZnO nanowires, the ZnSe substrate has a limit of detection of ∼25 ppm for 4-chlorophenol.