Jump to main content
Jump to site search


Enhancement of the Donnan Effect through Capacitive Ion Increase using an Electroconductive rGO-CNT Nanofiltration Membrane

Abstract

Graphene oxide (GO) based membrane in desalination is suffering from either low ion rejection or low water flux. Here, an electroconductive three-dimensional hybrid membrane was successfully fabricated by reduced GO and carbon nanotubes (GCM), and exhibits great potential to break the trade-off between permeability and selectivity when it is simultaneously performed as a filter membrane and an electrode. The intercalation of carbon nanotubes (CNTs) in the reduced GO matrix not only creates numerous water transport channels to promote permeability, but also increases active adsorption sites for salt ions. The larger specific surface area contributes more capacitive counter-ions onto the GCM under applied bias, which results in stronger electrostatic repulsion between capacitive ions on the GCM and counter-ions in solution, leading to an enhanced Donnan effect and remarkable salt rejection. The optimized GCM (containing 15% CNTs) achieves an outstanding NaCl rejection of 71%, which is three times higher than that without bias. Meanwhile, the GCM shows superior rejection for divalent cations and performs better under negative potential due to the pseudo-capacitance induced by the coordination of cations and oxygen-containing groups. These findings provide new insight for the future development of GO based membrane fabrication.

Back to tab navigation

Supplementary files

Publication details

The article was received on 16 Dec 2017, accepted on 02 Feb 2018 and first published on 02 Feb 2018


Article type: Paper
DOI: 10.1039/C7TA11003K
Citation: J. Mater. Chem. A, 2018, Accepted Manuscript
  •   Request permissions

    Enhancement of the Donnan Effect through Capacitive Ion Increase using an Electroconductive rGO-CNT Nanofiltration Membrane

    C. Hu, Z. Liu, X. Lu, J. Sun, H. Liu and J. Qu, J. Mater. Chem. A, 2018, Accepted Manuscript , DOI: 10.1039/C7TA11003K

Search articles by author

Spotlight

Advertisements