Novel Composite PEM with Long-Range Ionic Nanochannels Induced by Carbon Nanotube/Graphene Oxide Nanoribbon Composites

In the current study, carbon nanotube/graphene oxide nanoribbon (CNT/GONR) composites were obtained via a chemical “unzipping” method. Then novel CNT/GONR Nafion composite proton exchange membranes (PEMs) were prepared via a blending method. The CNT/GONR nanocomposites induce the adjustment of (—SO 3 – ) n ionic clusters in Nafion matrix to construct long-range ionic nanochannels and keep the activity of ionic clusters at the same time. This dramatically promotes the proton transport of the CNT/GONR Nafion composite PEMs at low humidity and high temperature. The proton conductivity of the composite PEM with 0.5 wt % CNT/GONR is as high as 0.18 S·cm –1 at 120 °C and 40%RH, nine times of recast Nafion (0.02 S·cm –1 ) at the same conditions. The 1D/2D nanostructure of CNT/GONR nanocomposite also contributes to restrain the methanol permeability of CNT/GONR Nafion. The composite PEM shows a one-order-of-magnitude decrease (2.84 × 10 –09 cm 2 ·s –1 ) in methanol permeability at 40 °C. Therefore, incorporation of this 1D/2D nanocomposite into Nafion PEM is a feasible pathway to conquer the trade-off effect between proton conductivity and methanol resistance.