Sulfonated poly(arylene ether sulfone) composite membrane having sulfonated polytriazole grafted graphene oxide for high-performance proton exchange membrane fuel cells

Abstract

We investigated the effect of graphene oxide (GO) and sulfonated polytriazole grafted graphene oxide (SPTA-GO) on sulfonated poly(arylene ether sulfone) (SPAES) based polymer electrolytes for application in proton exchange membrane fuel cells. GO was fabricated by the chemical oxidation of graphite and SPTA-GO was prepared via the click reaction using copper (I) catalyzed azide-alkyne 1,3-dipolar cycloaddition between ethynyl-terminated sulfonated polytriazole (E-SPTA) and azide functionalized GO (N-3-GO). All the SPAES based composite membranes with GO and SPTA-GO revealed better physical/chemical stabilities and mechanical strength than the pristine SPAES membrane, while noticeable improvement of proton conductivity was only observed in the SPAES composite membrane with SPTA-GO since the SPTA moiety attached on GO has both sulfonic acid and triazole groups that can introduce the additional proton conducting channels into the SPAES matrix. The maximum power density of the membrane electrode assembly employing the SPAES composite membrane with SPTA-GO reached up to 1.58 W cm(-2) at 80 degrees C and 100% RH condition, which is larger than that employing commercial Nafion 212 (1.33 W cm(-2)).