Wang M, He X, Hoenig E, Yan G, Peng G, Shi F, Radhakrishnan J, Hill G, Tiede DM, Zhou H, Liu C. Tuning Transport in Graphene Oxide Membrane with Single-site Copper (II) Cations.
iScience 2022;
25:104044. [PMID:
35359810 PMCID:
PMC8961230 DOI:
10.1016/j.isci.2022.104044]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/15/2022] [Accepted: 03/08/2022] [Indexed: 11/24/2022] Open
Abstract
Controlling the ion transport through graphene oxide (GO) membrane is challenging, particularly in the aqueous environment due to its strong swelling tendency. Fine-tuning the interlayer spacing and chemistry is critical to create highly selective membranes. We investigate the effect of single-site divalent cations in tuning GO membrane properties. Competitive ionic permeation test indicates that Cu2+ cations dominate the transport through the 2D channels of GO membrane over other cations (Mg2+/Ca2+/Co2+). Without/With the single-site M2+ modifications, pristine GO, Mg-GO, Ca-GO, and Cu-GO membranes show interlayer spacings of ∼13.6, 15.6, 14.5, and 12.3 Å in wet state, respectively. The Cu-GO membrane shows a two-fold decrease of NaCl (1 M) permeation rate comparing to pristine GO, Mg-GO, and Ca-GO membranes. In reverse osmosis tests using 1000 ppm NaCl and Na2SO4 as feeds, Cu-GO membrane shows rejection of ∼78% and ∼94%, respectively, which are 5%–10% higher than its counterpart membranes.
Single-site Cu2+ decreases the interlayer spacing of wet graphene oxide membrane
Single-site Cu2+ modifications can enhance salt rejection
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