Effect of peptizer on the properties of Nafion-Laponite clay nanocomposite membranes for polymer electrolyte membrane fuel cells

► Nafion-clay nanocomposites have been prepared by using peptized Laponite XLS. ► Acid activation of clay generates H3PO4 by the hydrolysis of Na4P2O7 peptizer. ► Water uptake of the nanocomposite is 1.5 times higher than the virgin Nafion. ► The maximum proton conductivity of 270.2 mS/cm has been achieved at 110 °C.