Detection of ethanol gas using In2O3 nanoparticle-decorated ZnS nanowires

Abstract

An In2O3 nanoparticle-decorated ZnS nanowire gas sensor was fabricated by following a three-step process. The ZnS nanowires were fabricated by the vapor-liquid-solid mechanism using ZnS powder as a precursor. The In2O3 nanoparticles were fabricated by a hydrothermal mechanism. The In2O3 nanoparticles were spin coated on the surface of the ZnS nanowires, and the resulting sample was annealed for 1h at 500°C in vacuum. The ethanol gas sensing response of these nanowires was 2.9 times higher than that of pristine ZnS nanowires when these sensors were exposed to 500ppm ethanol. The selectivity of the resulting sensor to ethanol gas among the other volatile organic compounds gases also improved by the decoration of ZnS nanowires with In2O3 nanoparticles. Furthermore, since ZnS and In2O3 are known as effective ethanol gas sensing materials, their combination creates a synergistic effect for ethanol gas sensing, selectivity, and sensitivity. In this study, we synthesized a hybrid structure containing In2O3 nanoparticles and ZnS nanowires to fabricate a high-response ethanol gas sensor. We also investigated the ethanol gas sensing mechanism of the resulting sensor.