Ultrafast-Selective Nanofiltration of an Hybrid Membrane Comprising Laminated Reduced Graphene Oxide/Graphene Oxide Nanoribbons

Abstract

In this study, reduced graphene oxide (rGO) and graphene oxide nanoribbons (GONRs) are used to fabricate a composite membrane that exhibits ultrafast water permeance (312.8 L m −2 h −1 bar −1 ) and precise molecular separation (molecular weight cutoff: 269 Da), which surpass the upper bound of previously reported polymer and graphene-based nanofiltration membranes. As two-dimensional GONR exhibits a width on the scale of nanometers, its nanochannels can be enlarged without hindering the stacking of rGO. Moreover, abundant oxygen-containing groups on the edge and surface of GONR enhance the electrostatic interactions between the filtered molecules and the membrane nanochannel. By the synergistic effect, rejection and water flux are considerably increased. Owing to the chemically stable nature of rGO, the composite membrane is highly stable in aqueous media (from acidic to alkaline) and is recyclable during repeated filtration tests.

Fabrication Techniques for Graphene Oxide-Based Molecular Separation Membranes: Towards Industrial Application

“…The vacuum filtration technique has also been widely utilized for fabricating hybrid and structured graphene membranes for dye and ion separation. Cho et al significantly increased the water permeance of nanofiltration membranes to 312.8 LMH/bar by depositing a rGO and GO nanoribbon (GONR) mixture on a porous support (Figure 2a) [22]. The high flux was a result from the nanochannels being enlarged by the intercalated GONR strips inside the rGO layer.…”

“…Otherwise, graphene is required to be functionalized to be soluble in water or eco-friendly solvents. [22]. Copyright 2019 American Chemistry Society; (b) GO layer deposition on wrinkled substrates for high water flux [23].…”

“…Moreover, the pressurized approach produced significant thickness reduction from 384 to 231 nm due to the increased ordering. These membranes were [22]. Copyright 2019 American Chemistry Society; (b) GO layer deposition on wrinkled substrates for high water flux [23].…”

The stability of a graphene oxide (GO) nanofiltration (NF) membrane in an aqueous environment: progress and challenges

“…7). 38,74,[77][78][79][80][81] The partially reduced GO can lead to weakened repulsive hydration Fig. 7 (A) Schematic illustration of the fabrication strategy and mechanism of the partially reduced graphene oxide (pfGO)-doped GO membranes with high stability in aqueous solutions and controllable lamellar spacing.…”

Laminated graphene oxide membrane for recovery of mercury-containing wastewater by pervaporation

“…However, pure GO membranes are prone to swell and collapse in water condition. To strengthen the structural stability of GO membranes, a large amount of cross-linking agents were applied, including polymers (Chen et al 2014;Cheng et al 2017;Pan, 2020;Park et al 2009;Suri et al 2019;Tian et al 2013), small molecules (An et al 2011;Feng et al 2016;Hung, 2014;Jia et al 2016;Liu et al 2020;Qian et al 2018;Wang, 2016b;Zhang et al 2020Zhang et al , 2015, ions (Chen, 2017;Gao et al 2019;Lin and Chen 2021;Park et al 2008;Yu et al 2017) and nano materials (Cho, 2019;Dong et al 2020;Shi, 2019;Xi et al 2016). Polyethylenimine (PEI) is a kind of hydrophilic and flexible polymer, and abundant amino group endows PEI molecules with positive charge.…”