(265b) Deconstructing Proton Transport through Atomically Thin Monolayer CVD Graphene Membranes

Selective proton permeation through the atomically thin lattice of graphene and other 2D materials offers new
possibilities for energy conversion/storage and novel separations. Practical applications necessitate scalable synthesis
via approaches such as chemical vapor deposition (CVD) that inevitably introduce sub-nanometer defects, grain
boundaries and wrinkles, and understanding their influence on H+ transport and selectivity for large-area membranes is
imperative but remains elusive. Using electrically-driven transport of protons and other ions through monolayer CVD
graphene we systematically deconstruct selective proton transport. Mitigation of large defects, wrinkles and tears via
interfacial polymerization results in selective proton permeation rates comparable to state-of-the-art proton exchange
membranes e.g. Nafion. Our work provides a new framework to assess H+ conductance and selectivity of large-area
2D membranes for practical applications.