Highly sensitive ethylene glycol gas sensor based on ZnO/rGO nanosheets

Abstract

ZnO/rGO nanosheets are fabricated by combining chemical precipitation and hydrothermal method. At the same time, high temperature annealing treatment is performed to further improve the gas-sensitive performance for ethylene glycol. The response value of ZnO/rGO-based gas sensor is up to 277 for 100 ppm ethylene glycol at an optimum operating temperature of 220 ℃. Compared with intrinsic ZnO gas sensor, the operating temperature is reduced and the response is increased by 1.1 times. The sensor has a fast response/recovery time of about 38 s/26 s and exhibits excellent cycle repeatability and stability. The detection limit is as low as 1 ppm. These excellent gas sensing properties are mainly attributed to a large specific surface and more active sites in ZnO/rGO nanosheets. In addition, based on the density functional theory (DFT), the charge transfer and the band structures are simulated. It is further confirmed theoretically our proposed gas sensing mechanism. It provides an effective research idea for real-time and ultra-rapid detection of ethylene glycol gas.