Gas-Sensitive Characteristics of Graphene Composite Tungsten Disulfide to Ammonia

Two-dimensional materials have outstanding application prospects in gas sensing. By constructing composite structures of various gas-sensitive materials, more-efficient and sensitive gas sensors can be further developed. After graphene is compounded with WS₂, the composite material can improve the gas detection performance. In this work, the adsorption energy and the electronic properties of a graphene/WS₂ structure were calculated by first-principles before and after adsorption of NH₃. The calculation results indicate that the bandgap of the material was appreciably reduced after NH₃ was adsorbed. In addition, a graphene/WS₂ gas sensor was prepared. The response of the sensor to NH₃ at a concentration of 100 ppm was 2.42% and 1.73% at 30 °C and 60 °C, respectively. Combining simulation with experiment, it is feasible to use graphene composite WS₂ to detect NH₃, which provides a new idea for applications of graphene and other composite materials in gas sensing.