Details

Autor(en) / Beteiligte

• Li, Zhongwu
• Han, Quan
• Qiu, Yinghua

Titel

Field-enhanced water transport in sub-nanometer graphene nanopores

Ist Teil von

• Desalination, 2022-04, Vol.528, p.115610, Article 115610

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• It is greatly important to improve water transport efficiency while maintaining strong salt rejection for nanoporous graphene membranes used in reverse osmosis seawater desalination. In this work, molecular dynamics simulations were applied to investigate water transport through sub-1 nm diameter graphene nanopores with different geometries under external electric fields. It was found that water concentration inside the nanopore with armchair edges increases with the electric field intensity. From analysis in micro-characteristics, water molecules become more structured and polarized near the nanopore armchair edges with a higher electric field intensity, indicated by the narrower distribution of water orientation, the longer water residence time and more hydrogen bonds per water molecule. With a specially designed armchair-edged graphene nanopore, the efficiency in reverse osmosis desalination was explored under external electric fields. Significantly enhanced water permeability was obtained that ~40 times higher than the existing desalination membranes while still remaining a complete salt rejection due to the accumulation of water and its improved transport velocity inside the nanopore. Graphical abstract showing the enhanced water permeability with the electric field intensity in the electric-field assisted reverse osmosis desalination (upper-left inset) using the graphene nanopore mainly due to the field-enhanced water concentration inside the nanopore (bottom inset). [Display omitted] •Electric fields assist water transport through sub-1 nm diameter graphene nanopores.•Enhanced water concentration, structuralization, and hydrogen bonds in armchair-edged graphene nanopores.•High performance reverse osmosis desalination achieved with armchair-edged graphene nanopores under electric fields.•Water permeability ~40 times higher than the existing desalination membranes remaining a 100% salt rejection.