Tuning the nanostructure of nitrogen-doped graphene laminates for forward osmosis desalination

Jun Ho Song, Ho Kyong Shon, Peng Wang, Am Jang, In S. Kim

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)

Abstract

Studies have concentrated on the physicochemical properties of graphene-based membranes that can replace polymeric membranes for use in forward osmosis (FO) systems. However, recent research studies have focused on mixtures of two or more different materials (e.g., graphene oxide and polymers) due to the need to reinforce underwater stability. Alternatives include reduced forms such as reduced graphene oxide to improve the stability and size-based selectivity, which have resulted in a narrow nanochannel that restricts water permeability. Herein, we propose the use of a novel nitrogen-doped graphene (NG) membrane to solve a trade-off between permeability and selectivity, investigating the nanostructure via N-doping reaction time. In an FO process, NG membranes achieved an outstanding specific salt flux of 0.18 g L-1, compared to commercial membranes (0.55 g L-1). The pyridinic-N bonding structure improved the permeability and selectivity under a similar nanochannel size because of its negatively polarized hole defects with the moderate energy barrier enabling water passage while blocking ions. Our results confirm the possibility of fabricating novel graphene-based FO membranes by tailoring the nitrogen-bonding structure, which will significantly help develop a process for improving the scalability of membrane materials.

Original languageEnglish
Pages (from-to)22025-22032
Number of pages8
JournalNanoscale
Volume11
Issue number45
DOIs
Publication statusPublished - 7 Dec 2019
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)

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