Tuning transport in graphene oxide membrane with single-site copper (II) cations
Mingzhan Wang,
Xiang He,
Eli Hoenig,
Gangbin Yan,
Guiming Peng,
Fengyuan Shi,
Julia Radhakrishnan,
Grant Hill,
David M. Tiede,
Hua Zhou,
Chong Liu
Affiliations
Mingzhan Wang
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
Xiang He
Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center and Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
Eli Hoenig
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
Gangbin Yan
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
Guiming Peng
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
Fengyuan Shi
Electron Microscopy Core, University of Illinois Chicago, Chicago, IL 60607, USA
Julia Radhakrishnan
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
Grant Hill
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
David M. Tiede
Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center and Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA
Hua Zhou
X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
Chong Liu
Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; Corresponding author
Summary: 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.
