Mass transport via in-plane nanopores in graphene oxide membranes

TL;DR

This study introduces a method to create and analyze in-plane nanopores in graphene oxide membranes, revealing how pore density influences water and ethanol transport, with implications for selective filtration.

Contribution

It provides a novel experimental approach to fabricate and investigate in-plane nanopores in graphene oxide membranes, combining ion irradiation with simulations to understand transport mechanisms.

Findings

Low pore densities increase water permeation.

High pore densities block pure water but allow ethanol-water mixture transport.

Functional groups and hydrogen network disruption are key to pore transport.

Abstract

Angstrom confined solvents in two-dimensional laminates travel through interlayer spacings, gaps between adjacent sheets, and via in plane pores. Among these, experimental access to investigate the mass transport through in plane pores is lacking. Here, we create these nanopores in graphene oxide membranes via ion irradiation with precise control over functional groups, pore size and pore density. Low ion induced pore densities result in mild reduction and increased water permeation for the membranes. Higher pore densities lead to pronounced reduction and complete blockage of pure water however allows permeation of ethanol water mixture due to weakening of hydrogen network. We confirm with simulations, that the attraction of the solvents towards the pores with functional groups and disruption of the angstrom confined hydrogen network is crucial to allow in plane pore transport.