Expanding the range of trackable environmental pollutants for Nafion based fuel cell type gas sensor

Abstract

Expanding the application field of fuel cell type gas sensors is of great significance for achieving high sensitivity, real-time gas detection at room temperature. Here, we developed a fuel cell type NO2 gas sensor based on MoS2 nanosheet/Carbon fiber (CF) sensing electrode and Nafion proton conductor, enabling the fuel cell type sensor to detect NO2 for the first time. The effect of MoS2 loadings(10, 20, 40, 60 and 80 mg) on the sensors’ performance and the sensitizing mechanism are investigated, the sensor containing 40 mg MoS2 exhibits the best performance, which can be attributed to the large number of active sites and efficient carrier transport properties of the corresponding electrode materials. At room temperature, the optimal sensor demonstrates a sensitivity of 45.6 nA/ppm to 1–50 ppm NO2 and an ultra-low detection limit of 28.8 ppb, both the response and recovery time are less than 60 s. This work not only develops a highly sensitive, reversible and fast response NO2 gas sensor, but also provides insights into sensing electrochemistry, material selection and catalyst/support materials, offering guidelines for future fuel cell type gas sensors to monitor a wider range of environmental pollutants.