The Study Of Gas Sensor Based On Graphene

In the fast developing society, a novel gas sensor with high sensitivity and fast response is of great significance to the protection of the environment and good health. Since the advent of grapheme, with its large surface ratio, high carrier mobility, high sensitivity, high signal to noise ratio and other characteristics, graphene causes a wide range of various fields of academic research, especially in the preparation of highly sensitive gas sensors.In this paper, high-quality graphene is successfully prepared by low-pressure chemical vapor deposition(LPCVD). On the basis of PMMA transfer method, we propose a new method for transferring, EC (ethyl cellulose) transfer method, greatly reducing the transfer process for graphene doping. In the preparation of high-performance graphene based gas sensors, ozone treatment is a very simple, cost-efficient way. Through the quantitative and qualitative discussions in the response, recovery and repetitive characteristics of graphene-based gas sensors with the different time ozone treatment for different concentrations of NO2gas, The sensitivity of the graphene based gas sensor with75s ozone treatment for10ppm NO2exceeds30%, which is2.8times more than the sensitivity of the pristine grapheme gas sensor. The detection limit concentration of NO2is estimated to be150ppb, which is lower than the World Health Organization (WHO) Air Quality Standards (200ppb,1-hr averages). By researching the response characteristics of graphene for HCHO, it is found that secondary grafting of graphene based HCHO gas sensor exhibits excellent response characteristics. The response for10ppm HCHO reaches more than10%, and the detection limit concentration is lppm. With the concentration of HCHO increases, the response of the graphene based HCHO gas sensor exponential increases, exhibiting excellent gas sensor performance and a high value.