Review—Functionalized Graphene Oxide Membranes as Electrolytes

Proton exchange membrane fuel cells (PEMFCs) typically use Nafion®, which has many drawbacks, such as high cost, crossover, and strenuous synthesis processes. As such, an alternative Nafion®-ionomer free proton conductor drawn significant interest. Graphene oxide (GOM) is a promising due to its hydrophilic nature attractive conductivity under humidified conditions. However, pristine GOMs have including reduction rate of negatively oxygenated functional groups during cell operation, showing excessive orientation dependence. We focused on nanocomposite-GOM (N-GOM) based PFSAs, hydrocarbon polymers, synthetic inorganic-organic biopolymers, metal-organic frameworks, micro- nano-engineered surfaces. GO nanosheets outstanding dispersion compatibility with ionomer matrices that can be functionalized by sulfonation, polymerization, phosphorylation, cross-linking, incorporated inorganic nanoparticles, blending matrix, microscale-nanoscale fabrication. The N-GOM exhibits high-performance improved conductivity, physicochemical properties, low crossover compared Nafion®. For instance, SCSP/SF membranes 3% (FGO) content displayed the highest 26.90 mS cm −1 best selectivity (methanol) 4.10 × 10 5 S −3 at room temperature. Moreover, new scalable, efficient chitosan (CA)-based composite (CA/GO) was fabricated. In addition, surface-patterned nanostructures in thin films increased PEMFC output power 950 mW −2 , higher than 590 for non-patterned Finally, we report optimal composition ratio each material N-GOM-based membrane. This review discusses most crucial developments outlines current progress revolutionary form PEM. general objective this research all possible modifications from perspective their practical application electrolytes cells.