Preliminary Study On The Development Of Sulfonated Graphene Oxide Membranes As Potential Novel Electrolytes For PEM Fuel Cells

Innovative graphene oxide (GO)-based self-assembling membranes have been prepared in order to study their possible application in PEMFCs as a solid proton-conducting electrolyte alternative to Nafion®. Firstly, a pure GO membrane has been produced as a benchmark, then it has been sulfonated with different quantities of sulfuric acid and characterized by using several techniques: Fourier transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), optical microscopy (OM), water uptake (WU) and ion exchange capacity (IEC). On the basis of IEC measurements, the corresponding degree of sulfonation was calculated. Preliminary impedance spectroscopy measurements have been also performed in order to obtain conductivity of the membranes and compare it to the one of a commercial Nafion membrane. A relation between IEC, degree of sulfonation and conductivity was found and the sulfonated membrane prepared with an acid/GO molar ratio of 20 showed the best results.