Tunable Nanochannels along Graphene Oxide/Polymer Core–Shell Nanosheets to Enhance Proton Conductivity

Simultaneous manipulation of topological and chemical structures to induce ionic nanochannel formation within solid electrolytes is a crucial but challenging task for the rational design of high‐performance electrochemical devices including proton exchange membrane fuel cell. Herein, a novel generic approach is presented for the construction of tunable ion‐conducting nanochannels via direct assembly of graphene oxide (GO)/poly(phosphonic acid) core–shell nanosheets prepared by surface‐initiated precipitation polymerization. Using this simple and rapid approach to engineer GO/polymer nanosheets at the molecular‐level, ordered and continuous nanochannels with interconnected hydrogen‐bonded networks having a favorable water environment can be created. The resulting membranes exhibit proton conductivities up to 32 mS cm −1 at 51% relative humidity, surpassing state‐of‐the‐art Nafion membrane and all previously reported GO‐based materials.