A chloride ion-selective boron nitride nanotube

Combined density functional theory and molecular dynamics simulations were performed to investigate ionic selectivity of boron nitride nanotubes (BNNTs). A finite-length (10, 10) BNNT with a diameter of 1.356 nm immersed in a reservoir of 1 M KCl solution can selectively conduct Cl^- ions, while K⁺ ions barely reach the center of the nanotube and do not conduct. In contrast, a (10, 10) single-walled carbon nanotube of approximately the same diameter immersed in a 1 M KCl solution can selectively conduct K⁺ ions through the nanotube. We investigate the potential of mean force analysis, binding energy calculations, the water structure, and its orientation, to explain the selectivity of BNNT.