Constructing Long-Range Transfer Pathways with Ordered Acid–Base Pairs for Highly Enhanced Proton Conduction

Acid–base pairs hold great superiority in creating proton defects and facilitating proton transfer with less or no water. However, the existing acid–base complexes fail in assembling into ordered acid–base pairs and thus cannot always take full advantage of the acid–base synergetic effect. Herein, polymer quantum dots with inherent ordered acid–base pairs are utilized and anchored on dopamine-coated graphene oxide, thus forming into long-range conducting pathways. The resultant building blocks (nPGO) are integrated in a sulfonated poly(ether ether ketone) matrix to fabricate composite membranes. The constructed long-range transfer highways with ordered acid–base pairs impart to the composite membrane significantly enhanced proton conduction ability. Under the hydrated state, the composite membrane attains 91% increase over the control membrane in conductivity, and the single-cell fuel based on the membrane achieves 71% promotion in maximum power density. Under anhydrous conditions, more striking augment in conduction is observed for the composite membrane, reaching 7.14 mS cm–1, almost 10 times of the control membrane value (0.78 mS cm–1). Remarkably, such anhydrous proton conduction performance is even comparable to that of the composite membrane impregnated with ionic liquids, which is hard to realize with conventional fillers. Collectively, these results endow composite membranes great potential for applications in hydrogen-based fuel cells, sensors, and catalysis.