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 WS, the composite material can improve the gas detection performance. In this work, the adsorption energy and the electronic properties of a graphene/WS structure were calculated by first-principles before and after adsorption of NH. The calculation results indicate that the bandgap of the material was appreciably reduced after NH was adsorbed. In addition, a graphene/WS gas sensor was prepared. The response of the sensor to NH 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 WS to detect NH, which provides a new idea for applications of graphene and other composite materials in gas sensing.