Nafion–zirconia nanocomposite membranes formed via in situ sol–gel process

Crystallized zirconia nanoparticles with diameters of 6.3 ± 0.5 nm were in situ formed in Nafion solution through sol–gel process. Nafion molecules were self-assembled onto zirconia nanoparticles through electrostatic interactions and prevent the further growth of initial formed particles. The Nafion–zirconia nanocomposite membranes were formed using a recasting process. It was found that the addition of zirconia nanoparticles did not affect the crystallinity and structure of Nafion in the membrane significantly. The formed Nafion–zirconia nanocomposite membrane shows enhanced water retention ability at 100 °C compared to recast pure Nafion membrane, especially at medium and high relative humidity. This work demonstrates the potential of Nafion–zirconia nanocomposite membranes for PEMFC applications.