Detection of acetylene (C2H2) gas using Ag-modified ZnO/GO nanorods prepared by a hydrothermal synthesis

It is very important to detect the acetylene (C2H2) gas content from fruits which have been artificially ripened by carcinogenic calcium carbide. Herein, we demonstrate a chemiresistive based C2H2 gas sensor using Ag-modified zinc oxide and graphene oxide (Ag–ZnO/GO) nanocomposite. The addition of GO and Ag to ZnO nanorods increases the intrinsic chemical activity of metal oxide and C2H2 spillover, resulting sensing properties enhanced. The morphological, structural and chemical properties of pure ZnO, ZnO/GO and Ag–ZnO/GO are analyzed using various measurement tools. These sensors are investigated at various operating temperatures from 50 to 350 °C at 5–100 ppm concentrations of C2H2. Ag–ZnO/GO sensor exhibits an excellent sensing response of 187.34% for 100 ppm C2H2 gas with response/recovery time period of 13/780 s, respectively at an optimum operating temperature of 250 °C. The sensor is highly selective towards C2H2 in the presence of different interfering gases such as H2, methanol, ethanol, acetone, ethylene, carbon dioxide, chlorine and methane. The sensor also possesses an excellent reproducible response and good stability, suggesting a potential candidate for C2H2 gas sensing application.