Enhanced Graphene Oxide-Nafion® membranes for proton exchange membrane water electrolysis

The proton exchange membrane (PEM), which is exposed to chemical reactions, mechanical stresses, and temperature fluctuations, is one of the most vulnerable parts of PEM Water Electrolyzers. Perforation or failure of this membrane risks total cell destruction from hydrogen and oxygen combination. Instead of traditional casting methods to produce reinforced PEMs, a novel approach was explored depositing a composite Nafion®-Graphene Oxide (GO) layer on an extruded commercially available Nafion® 115 membrane. A GO-Nafion® ink was formulated, and a 20-micrometer composite GO-Nafion® layer was ultrasonically sprayed onto the Nafion® 115 membrane. Various thermal treatments were explored to bond the composite layer to the extruded membrane. This method yielded more hydrophilic membranes and increased strain and tensile load capacity, especially in samples annealed at higher temperatures. Thermogravimetric analysis indicated that GO-Nafion® membranes required higher temperatures for thermal breakdown. When deposited on the cathode side, the composite layer improved mechanical and thermal properties without affecting electrochemical performance, despite increasing membrane thickness by over 15%. However, deposition on the anode or both sides reduced electrochemical performance by approximately 9% and 15%, respectively. Nonetheless, all GO-Nafion® membranes demonstrated good stability over time, highlighting the Nafion®-GO blend as a promising material for electrolysis applications.