Room temperature hydrogen sensor based on Nafion and Pd/CF sensing electrode

The development of high-performance H 2 gas sensors is a challenge for safe operation in the high-risk area of flammable and explosive. In this work, Pd/CF is used as a sensing material in fuel cell type sensors and the effect of Pd loading (5 wt%, 10 wt% and 20 wt%) on the sensors’ performance is investigated. The sensor based on Pd(10 wt%)/CF shows the best sensing performance which can be attributed to both the optimal balance of Pd content and utilization to produce the most active sites for the catalytic reaction and the highest conductivity of the membrane electrode assembly (MEA). These are confirmed by EDS images, cyclic voltammetry curve and complex impedance curves. The optimal sensor has a response value of about − 60 μA to 5000 ppm H 2 and a sensitivity of − 0.0131 μA/ppm to 200–10000 ppm H 2 at room temperature (25 °C). In addition, with the advantages of no heating, no external voltage, simple fabrication process, high linearity, good repeatability and long-term stability, the sensor in this work possesses very broad development prospect.