Enhanced proton conductivity of sulfonated poly(ether ether ketone) membranes by constructing cation-[pi] through doping ammonium ionic liquid and graphene oxide

In this paper, sulfonic acid functionalized benzothiazole ionic liquid ([[(C[H.sub.2]).sub.3]S[O.sub.3]HBth] [[H.sub.2]P[O.sub.4]]) and graphene oxide were combined together through the cation-[pi]. The sulfonated poly (ether ether ketone) was doped with ionic liquid-modified GO (IL-GO) to prepare the SPEEK/IL-GO composite membrane through the solution casting method. The - S[O.sub.3]H and benzothiazole rings act as both proton acceptors and proton donors during proton transport and can replace the role of water in medium- and high-temperature environments, increasing the proton transport sites to a certain extent and increasing the proton conductivity of the SPEEK/IL-GO composite membrane. The proton conductivity of the SPEEK/IL-GO-2 composite membrane achieved an 18.02 mS/cm at 120[degrees]C, which is 2.43 times higher than that of the pristine SPEEK membrane. This paper provided a method for increasing proton conductivity and limiting IL loss of the SPEEK membrane. Highlights * [[(C[H.sub.2]).sub.3]S[O.sub.3]HBth][[H.sub.2]P[O.sub.4]] and graphene oxide were combined through cation-[pi]. * The benzothiazole ring and -S[O.sub.3]H form acid-base pairs. * The proton conductivity of SPEEK/IL-GO-2 membrane achieved 18.02 mS/cm. KEYWORDS cation-[pi], graphene oxide, high proton conductivity, proton exchange membranes
1 | INTRODUCTION The massive use of traditional fossil energy sources has caused problems such as environmental pollution and resource shortages. (1-3) New energy technologies are constantly being explored in [...]