Mixed Nanosheet Membranes Assembled from Chemically Grafted Graphene Oxide and Covalent Organic Frameworks for Ultra-high Water Flux

Niaz Ali Khan, Jinqiu Yuan, Hong Wu, Li Cao, Runnan Zhang, Yanan Liu, Lianshan Li, Ata Ur Rahman, Roni Kasher, Zhongyi Jiang

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

2D graphene oxide (GO) membranes attract great attention because of their ultrathin thickness and superior molecular sieving ability, but their low flux and instability in aqueous environments are still the major challenges for practical applications. In this study, we designed hybrid nanosheets from chemically grafted GO and covalent organic frameworks (COFs) as building blocks to fabricate mixed nanosheet membranes. The covalent triazine framework (CTF), a triazine-based COF, is exfoliated into nanosheets and then reacted with GO to form the GO-CTF hybrid nanosheets, which are then assembled into GO-CTF mixed nanosheet membranes. The GO-CTF membranes show a layered configuration of ca. 32 nm thickness. The incorporation of CTF nanosheets inappreciably changes the interlayer distance of GO-CTF membranes, ensuring high rejections to organic dyes (>90%); meanwhile, the CTF nanosheets afford extra through-plane channels that significantly shorten the water transport pathway. The GO-CTF membranes exhibit a water flux of 226.3 L m-2 h-1 bar-1, more than 12-fold higher than pure GO membranes. Besides, the strong chemical bonds between GO and COF render the GO-CTF membranes notably enhanced stability. Grafting of porous nanosheets onto nonporous nanosheets to acquire hybrid nanosheets as building blocks opens a new avenue to the fabrication of 2D membranes with promising application potential.

Original languageEnglish
Pages (from-to)28978-28986
Number of pages9
JournalACS applied materials & interfaces
Volume11
Issue number32
DOIs
StatePublished - 14 Aug 2019

Keywords

  • covalent organic frameworks nanosheets
  • cross-linked graphene oxide
  • dye separation
  • high flux membranes
  • mixed nanosheets

ASJC Scopus subject areas

  • Materials Science (all)

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