Poly (arylene ether ketone sulfone)s functionalized with diethylenetriamine-modified graphene oxide as proton exchange membranes for fuel cells

Abstract

In this paper, composite proton exchange membranes (PEMs) based on functionalized graphene oxide (NGO) and carboxylated sulfonated poly aryl ether ketone sulfone (C-SPAEKS) were successfully synthesized. Functionalized graphene oxide was synthesized using graphene oxide as a substrate, and then diethylenetriamine (DETA) was chemically bound to the graphene oxide. The 1H NMR, FT-IR and XPS were used to characterize the NGO and composite membranes. The results show that the composite membranes have good proton conductivity, dimensional stability and electrochemical performance. The swelling rate of all the composite membranes was less than 18%, which indicates that they have good dimensional stability. Compared to C-SPAEKS membrane (34.8 mS cm-1 at 20 °C, 109.8 mS cm-1 at 90 °C), the proton conductivities of C-SPAEKS/GO-0.75 membrane (52.4 mS cm-1 at 20 °C, 171.1 mS cm-1 at 90 °C) were significantly improved. Meanwhile, the C-SPAEKS/NGO-0.75 achieved peak power density of 407.77 mW cm-2 at high OCV of 0.9576 V. Such a result is much superior to the C-SPAEKS membrane (0.8973 V, 190.72 mW cm-2) and the Nafion 117 (0.99 V, 302 mW cm-2), and demonstrated good single-fuel cell performance. In summary, it can be well concluded that functionalized GO as filler makes an significant contribution in improving the overall performance of the composite membranes.