High-performance gas sensor based on ZnO nanowires functionalized by Au nanoparticles

One-dimensional (1D) semiconductor nanostructure has been widely used for gas sensor devices. In this work, a high performance gas sensor based on Au-functionalized ZnO nanorods was fabricated. Au nanoparticles were successfully immobilized onto the surface of ZnO nanorods to serve as a sensitizer by a facile solution reduction process. The hybrid Au/ZnO nanorods have been systematically characterized by XRD, SEM, EDS, TEM and optical absorption spectrum. Gas sensing tests reveal that the Au/ZnO sensor has remarkably enhanced performance compared to pure ZnO. It could detect ethanol gas in a wide concentration range with very high response, fast response-recovery time, good selectivity and stable repeatability. The possible sensing mechanism is discussed. The superior sensing features indicate the present Au/ZnO nanorods are promising for gas sensors.