Designing a high-performing amorphous porous framework of the proton-conducting membrane with inherent SO3H moieties in the aromatic chain and impregnating the proton source is beneficial for developing an excellent electrolyte for the proton exchange membrane fuel cell. In this work, we synthesize the porous sulfonated poly­(ether sulfone) (PSPES) nanocomposite membranes with excellent proton conductivity and stability via modified non-solvent-induced phase inversion. The hydroxylated boron nitride (HBN) was prepared from the bulk BN through simple liquid exfoliation and hydroxylation, which yielded the few-layered sheets. The direct inclusion of HBN into the PSPES will be anchoring or filling on the microporous channels of the membrane, yielding outstanding stability with HBN retention ability and high conductivity. Thereby, an excellent synergistic effect between the PSPES and HBN through the functional groups (SO3H–OH) is shown, producing the proton transport bridge and continuous proton transfer channels within the porous structure. Besides, the current and power density of the 3.5 wt % HBN reinforced PSPES (PSPES-HBN2) membranes were improved to 795 mA cm–2 and 220 mW cm–2. The interconnected microporous PSPES-HBN2 membrane shows an excellent proton conductivity of 77.4 ± 3.87 mS cm–1 at 80 °C with 100% humidity and notably reduced membrane degradation after a 120 h durability test.

Proton exchange membrane (PEM) for H 2 /O 2 fuel cell are made as sandwich assembly of sulfonated poly(ether sulfone) (SPES) with sulfonic acid functionalized multiwalled carbon nanotubes (SMWCNT). The SMWCNT occupies at the middle layer enhances the interfacial interplay and interconnects the nano-phase separation via hydrogen bond between the sulfonic acid of SPES and SMWCNT. The sandwich structure improves the integration of hydrophilic and hydrophobic layers of SPES and SMWCNT, that obliviously enhance the tensile and mechanical property of the membrane. Thus promotes the continuous proton conducting channels through the sandwiched morphology by using the proton hopping mechanism. The 1.5 wt% of SMWCNT in SPES (G3) offers high proton conductivity, current and power density values at 80 C under 100% RH, which are 72.0 Â 10 À3 S cm À1 , 778.26 mA cm À2 and 173.29 mW cm À2 , respectively. Within addition to remarkable durability, the OCV degradation is about 0.02 V after 15 hours of durability test and H 2 permeability of 2.14 barrer. The excellent thermal stability of 91.2 wt% at 150 C and the Young's modulus of 2208 ± 110 MPa was attained by the G3, which strongly suggest that the promising nature of PEM.