▎ 摘　　要

We demonstrate the effects of the layer distance and amounts of oxygen functional groups on ion permeation through a graphene oxide (GO) membrane. The Cu2+ permeation rate had a good linear relationship with the layer distance of GO membrane. Also, the relationship was continuously maintained across the different methods used to tune layer distance. Ultimately, we successfully tuned the Cu2+ permeation rate in the range 0-2 mol h(-1) m-(2) by controlling layer distance.