Enhancing water desalination in graphene-based membranes via an oscillating electric field

Abstract

Water desalination methods on the basis of newly developed graphene-based membrane have been introduced as a more efficient alternative for the conventional water purification technologies such as classical thermal desalination and reverse osmosis (RO). However, the increase of water permeation rate and ion rejection are still the main subjects in this field. In this study, a new method based on using oscillating electric field is proposed to improve the performance of nanoporous graphene. The effects of the amplitude and oscillation frequency of the electric field and the pore size of the membrane on the water permeation and salt rejection are studied by conducting molecular dynamics simulations. The results of this research reveal that by applying oscillating electric field with proper amplitude and frequency, water flow rate will be increased by 59.6% with the ion rejection of 100% compared to the case with no electric field. • Applying an oscillating electric field can improve the performance of graphene. • The effects of the amplitude and oscillation frequency were studied. • The flow rate can increase by 59.6% with the ion rejection of 100%. • The effects of pore size on the permeation and salt rejection were studied. • By positively charging the pore edge atoms the flow and salt rejection decrease.