Ab Initio Molecular Dynamics Investigation on the Permeation of Sodium and Chloride Ions Through Nanopores in Graphene and Hexagonal Boron Nitride Membranes

Abstract

AbstractNanoporous membranes promise energy‐efficient water desalination. Hexagonal boron nitride (h‐BN), like graphene, exhibits outstanding physical and chemical properties, making it a promising candidate for water treatment. We employed Car‐Parrinello molecular dynamics simulations to establish an accurate modeling of Na+ and Cl− permeation through hydrogen passivated nanopores in graphene and h‐BN membranes. We demonstrate that ion separation works well for the h‐BN system by imposing a barrier of 0.13 eV and 0.24 eV for Na+ and Cl− permeation, respectively. In contrast, for permeation of the graphene nanopore, the Cl− ion faces a minimum of energy of 0.68 eV in the nanopore plane and is prone toward blockade of the nanopore, while the Na+ ion experiences a slight minimum of 0.03 eV. Overall, the desalination performance of h‐BN nanopores surpasses that of their graphene counterparts.