Speaker
Description
Two-dimensional (2D) monolayer nanomaterials are the thinnest possible membranes with interesting
selective permeation characteristics. Among two-dimensional materials, graphenes and hexagonal boron
nitride (h-BN) are the most promising membrane materials, which can even allow the separation of
proton isotopes. The current work aims at understanding the higher reported permeability of h-BN by
sequential doping of B and N atoms in graphene nanoflakes. The kinetic barriers were calculated with
two different models of graphenes; coronene and dodecabenzocoronene via zero-point energy
calculations at the transition state for proton permeability. The lower barriers for h-BN are mainly due to
boron atoms. The trends of kinetic barriers are B < BN < N-doped graphenes. The permeation selectivity
of graphene models increases with doping. Our studies suggest that boron-doped graphene models
show an energy barrier of 0.04 eV for the permeation of proton, much lower than that of the model
graphene and h-BN sheet, while nitrogen-doped graphenes have a very high energy barrier up to
7.44 eV for permeation. Therefore, boron-doped graphene models are suitable candidates for proton
permeation. Moreover, the presence of carbon atoms in the periphery of BN sheets has significant
negative effects on the permeation of proton isotopes, an unexplored dimension of the remote
neighboring effect in 2-D materials. This study illustrates the need for permeation study through other
hetero-2D surfaces, where interesting hidden chemistry is still unexplored.
