Enhanced Proton Conductivity of Graphene Oxide/Nafion Composite Material in Humidity Sensing Application

In this work, we report the performance of graphene oxide (GO) and Nafion composite as highly responsive humidity sensor. GO was synthesized using modified Hummers and Offeman method and was mixed with Nafion ionomer. The hybrid sensing layer was characterized using atomic force microscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis and Fourier transform infrared spectroscopy. GO/Nafion composite solution was drop-casted on patterned gold electrodes on Si/SiO2 substrate to fabricate the sensor. GO/Nafion-based sensor was exposed to six different humidity level (40%-88%) and large response was obtained due to high proton conductivity of GO and Nafion. The sensor response varied from ~1400 times (40% RH) to ~18 000 times (88% RH). Our GO/Nafion based humidity sensor also exhibited very fast response and recovery times with excellent reproducibility and stability. The reported work shows that GO/Nafion is a promising candidate to be used in development of a modern highly sensitive humidity sensor.