Hydrogen and humidity sensing characteristics of Nafion, Nafion/graphene, and Nafion/carbon nanotube resistivity sensors

In this work, Nafion-based resistivity sensors were investigated for their efficiencies in hydrogen and humidity sensing characteristics. The sensors comprise of Nafion coated on two types of carbon nanomaterials, graphene and carbon nanotubes, respectively, as sensing platform interconnect between pairs of microelectrodes. The study showed that the hydrogen sensing of Nafion/CNT sensor was higher than Nafion/graphene sensor, and its response and recovery times were also faster. In the absence of carbon nanomaterials, Nafion-only sensor was also capable of detecting the presence of hydrogen but its sensing responses were lower with higher signal drift. In humidity sensing, both Nafion/CNT and Nafion/graphene sensors demonstrated lower and inverse humidity responses compared to Nafion-only sensor. Among the fabricated sensors, Nafion/CNT materials were found to offer promising sensing platform for application in real-time hydrogen gas and humidity detection.