Nanocomposite proton exchange membranes based on sulfonated polyethersulfone and functionalized quantum dots for fuel cell application

Abstract

In this work novel nanocomposite proton exchange membranes were prepared using sulfonated polyethersulfone (SPES) with incorporation of ZnS functionalized quantum dots (FQDs) with a solution-casting method. The effect of functionalized groups (–COOH and NH2) of ZnS FQDs on the SPES membrane properties such as proton conductivity and performance was investigated. The highest proton conductivity of the nanocomposite membranes was achieved 116 mS/cm at 90°C. The nanocomposite membranes containing 2 wt% of ZnS FQDs displayed constant proton conductivity life time in 180 hours and fuel cell life time in 70 hours at 90°C, 98% RH, which confirmed strong interaction between functionalized group of ZnS FQDs and –SO3H groups of SPES. The power density of the SPES-ZnS FQDs nanocomposite membranes (DS of SPES: 45% and ZnS FQDs content: 2 wt%) obtained 0.53 W/cm2 in 98% RH, 0.5 V, and 90°C. The results confirmed that the prepared nanocomposite membranes with remarkable performance can be used as useful membranes for fuel cells.