Fabrication of electrospun sulfonated poly(ether sulfone) nanofibers with amino modified SiO2 nanosphere for optimization of nanochannels in proton exchange membrane

Abstract

Nanofibers have been widely used for the construction of proton channels in proton exchange membranes (PEMs), and the optimization and control of proton channels have become a focus in this research area. In this work, we design and fabricate optimized and efficient proton transport channels in PEMs by introducing of sulfonated poly (ether sulfone) nanofiber with amino–modified SiO2 protuberance structures. The protuberance structures improve the strong interactions between the functional groups of nanofibers and matrix, resulting in an increased density of proton-conducting sites and improvement in membrane properties. Notably, Nafion/SPES/SiO2–3% possesses a low methanol permeability of 7.22 × 10−7 cm2s−1 and a high proton conductivity of 0.23 S cm−1 at 80 °C in water. Consequently, the Nafion/SPES/SiO2 membrane demonstrates a maximum power density of 77.22 mW cm−2 in a direct methanol fuel cell test system, which is 42.34% higher compared to the value of Nafion membrane (54.25 mW cm−2). This study successfully explores the preparation route of nanofiber with protuberance structures successfully, and highlights the potential benefits of this novel nanofiber structure in the PEM field.