Ethanol sensing with Au-modified ZnO microwires

A room temperature ethanol sensor based on Au-modified zinc oxide microwires (Au/ZnO MWs) is demonstrated. Au nanoparticles (Au NPs) were immobilized via ion sputtering onto the surface of CVDfabricated ZnO microwires (ZnO MWs) to serve as sensitizers. Au modification was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and photoluminescence. Gas-sensing tests indicated that the modified microwires exhibited an enhanced performance relative to the unmodified ZnO microwires over a wide gas concentration range, with very stable repeatability, fast recovery time and high sensing response and selectivity. A sensing mechanism is described in terms of localized surface plasmon resonance (LSPR) effect of Au NPs. The superior sensing characteristics indicate the device's potential applications as room-temperature gas sensor, and a straightforward and economical fabrication also makes it very attractive for more widespread use. (C) 2015 Elsevier B.V. All rights reserved.