Sulfonated graphene oxide for proton exchange membranes with significantly enhanced proton conductivity

To improve the proton conductivity of the proton exchange membranes (PEM), an amino derivative with sulfonic acid groups was used to modify graphene oxide (GO), resulting in sulfonated graphene oxide (S-GO), which was then incorporated into a perfluorinated sulfonic acid (PFSA) matrix to fabricate a PFSA/S-GO composite membranes. Elevating the doping concentration of S-GO within the composite membrane has resulted in enhanced proton conductivity, outperforming the baseline PFSA membrane across a range of temperatures. Notably, this conductivity ascended to 291.89 mS/cm when measured at 80 degrees C under conditions of 100% RH. Furthermore, the strong interface interaction between sulfonated graphene oxide and perfluorinated sulfonic acid polymer endowed the composite proton exchange membrane with excellent thermal stability and mechanical strength.