Strain tunable nanoporous r-N-GDY membrane for efficient seawater desalination

Abstract

Seawater desalination is believed to be the most promising solution to solve the current crisis of global freshwater deficiency. The applications of nanoporous graphene filters and biological water channels have greatly improved the desalination efficiency. Here, we report the auspicious performance of a tunable nanoporous desalination filter using monolayer r-N-GDY through combination of molecular dynamics simulations and first-principles calculations. In striking contrast to graphene, the r-N-GDY filter can be switched between a high-flux “open” state and a “closed” state by applying tensile strain, yielding a highly tunable nanopore interface. The critical transition between “open” and “closed” states occurs at a moderate strain of 4%. For the “open” state, the water permeability reaches 47 L per cm² per day per MPa with strong ion rejection which is superior to that of almost all previously reported membrane structures. Given these advantages, the r-N-GDY presents great prospects as a controllable nanoporous membrane for efficient desalination and other applications.