Investigating the performance of functionalized and pristine graphene oxide impregnated Nexar™ nanocomposite membranes for PEM fuel cell

Membranes are considered a key component for PEM fuel cell performance. Numerous fluorinated and non-fluorinated hydrocarbon materials are explored as PEM membranes; however, new membrane materials are still being quested to overcome their existing challenges. In this context, Nexar™ (non-fluorinated hydrocarbon) and its modified forms are investigated in the present work as a new and promising membrane material for PEM fuel cells. The pristine Nexar™ is modified with graphene oxide (GO) and sulfonated graphene oxide (GO-SO3H) to prepare the nanocomposite membranes, which are later characterized through SEM, FTIR, and XRD. Membrane thickness, protonic resistivity, and hydration number are determined. The prepared membranes are tested against water uptake, swelling ratio, IEC value, and proton conductivity necessary for PEM fuel cell membrane operation. The water uptake of GO modified (5 wt% loading) membrane increased up to 33%; however, it decreased by 50% in the case of the GO-SO3H membrane, still better than Nafion. Similar behavior is observed for the swelling ratio for both GO and GO-SO3H membranes. The IEC value of GO and GO-SO3H membranes decreased (∼25% for GO and ∼10% for GO-SO3H) compared with Nexar™ membrane, while GO-SO3H membranes showed improvement in IEC values compared to GO-based membranes. The proton conductivity also changes , leading to a decreasing value (∼78%) for GO-membrane and an increasing value (∼12%) for GO-SO3H membrane comparing Nexar™. Thus, Nexar™-GO-SO3H showed better performance comparing GO modified and pristine Nexar™.