▎ 摘　　要

NOVELTY - Proton exchange membrane comprises perfluorosulfonic acid ionomer, graphene oxide and a hydrocarbon-based polymer. USE - The membrane is used for a water electrolysis system. ADVANTAGE - The membrane has improved proton conductivity, dimensional stability and heat stability, exhibits excellent durability, and improves performance of a water electrolysis system. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for producing the membrane involving (1) grafting the perfluorosulfonic acid ionomer to the graphene oxide surface and (2) dispersing the perfluorosulfonic acid ionomer grafted onto the surface of the graphene oxide in a base polymer to obtain the product.