Thermally Reduced Graphene Oxide Membrane with Ultrahigh Rejection of Metal Ions’ Separation from Water

Zhao, Zeyuan; Ni, Shuainan; Su, Xiang; Gao, Yun; Sun, Xiaoqi

doi:10.1021/acssuschemeng.9b02972

Cited by 35 publications

(30 citation statements)

References 46 publications

(97 reference statements)

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“…Experimental results show that if the thickness of the rGO layer increases from 20 to 59 nm (Figure S5) then the rejection ratio of MB by the rGO/CNT/PVDF membranes increases from 12.4% to greater than 99.9% (Figure ). The increase in the rejection ratio with an increase in the thickness of the rGO layer can be also observed during the filtration of the RhB solution (Figure ) and was shown in previous studies. − It can be thus concluded that some molecules could be rejected within the rGO separation layer, which can be further confirmed by X-ray diffraction (XRD) analysis (Figure S6) and depth-profiling X-ray photoelectron spectroscopy (XPS) analysis (Figures S7 and S8).…”

Section: Results and Discussionsupporting

confidence: 81%

Electrochemical Cleaning of Fouled Laminar Graphene Membranes

Wei

Zhao

Dong

et al. 2020

Environ. Sci. Technol. Lett.

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Laminar graphene (including reduced graphene oxide (rGO)) membranes have recently received significant attention because of their potentially excellent permeability and selectivity; however, their fouling problem associated with the foulants blocked within graphene nanochannels has not been thoroughly investigated. This study confirms the blockage of molecules within the rGO membranes by investigating their rejection ratios at various membrane thicknesses and then presents an electrochemical in situ cleaning strategy (with the membrane as anode) aimed at oxidative decomposition of the foulant molecules. This method could restore the permeance (<3.0 L m −2 h −1 bar −1 ) after the filtration of the methyl blue solution to greater than 9.2 L m −2 h −1 bar −1 in 20 min at a voltage of 2.5 V without suspending the filtration process, resulting in a recovery ratio of greater than 94%. Such a high recovery ratio could still be achieved after six "fouling−cleaning" cycles. The process is energy efficient with only approximately 6.7 Wh consumed for 1 m 2 of membrane area and a single cleaning. In addition, the electrochemical cleaning could largely avoid the damage of the membrane structure by preventing the formation of microbubbles, nanoparticles, and highly active hydroxyl radicals.

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Section: Results and Discussionsupporting

confidence: 81%

Electrochemical Cleaning of Fouled Laminar Graphene Membranes

Wei

Zhao

Dong

et al. 2020

Environ. Sci. Technol. Lett.

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“…Overall, the O/C ratios of the GO membrane, WRGO membrane, MRGO membrane, and FRGO membrane are 0.47, 0.45, 0.42, and 0.38, respectively. The C1 s XPS spectrum of the GO-based can be fitted with four components: C-C/C=C (284.8 eV), C-OH/C-O-C (286.7 eV), C=O (287.6 eV), and O=C-OH (288.8 eV) [13,36]. Figure 2d shows the detailed spectral fitting and interpretation of the GO-based membranes.…”

Section: Resultsmentioning

confidence: 99%

“…Thermally reduction methods, another main method for rGO membrane, can avoid the above problems [34]. By adjusting the annealing temperature and duration, the degree of the reduction can be tuned, and the interlayer spacings of the rGO membranes are changed, correspondingly [35][36][37]. Generally, the adopted annealing temperature for rGO membranes is above 120 • C over one hour [38].…”

Section: Introductionmentioning

confidence: 99%

Fast Reduced Graphene-Based Membranes with High Desalination Performance

et al. 2021

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Graphene-oxide (GO) membrane with notable ions sieving properties has attracted significant attention for many applications. However, because of the water swelling of GO membrane, the rejection of monovalent metal cations is generally low. In this work, we developed a fast and facile method to fabricate a kind of reduced GO membranes using the thermal treatment method at 160 °C for only one minute, which denoted as fast reduced GO membrane (FRGO). Surprising, the FRGO membrane represents high ion sieving ability and ultrahigh water/ions selectivity, compared with other reduced GO membranes with similar average interlayer spacings, and even superior to most of GO-based membranes reported in literature. Building on these findings, we provide a new light on fabricating of energy- and environment-related high desalination performance of GO-based membranes as well as a new insight into the transport mechanism within 2D laminar nanochannels.

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“…This could be partially supported by previous studies on the hydration expansion of GO layers in water, , wherein a broad and weak XRD peak, relative to dry conditions, infers that the GO-layered structure is not well-ordered, as a result of random interstratification of multiple hydrated layers. Actually, in a recent work, the weak and broad XRD peak for GO membranes has also been assigned as the curved interlayer model with varied interlayer distances.…”

Section: Resultsmentioning

confidence: 99%

Molecular Simulation on Thermodynamic Swelling Behavior of Bilayer Graphene Oxide in Solvents

Tong

Cui

et al. 2021

J. Phys. Chem. C

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Solvation swelling for graphene oxide (GO)-layered materials is a key property that determines the capacity for species permeation and adsorption inside GO interlayers, which hold great promise for wide applications. Currently, diverse variations and controversies for the measured interlayer spacings appear in the literature. While experimental measurement could provide a macroscopic image of interlayer spacings for layered GOs, a theoretical simulation of the interlayer swelling for GO-layered materials in solvent media is very essential, which is able to provide a fundamental basis for further understanding the complicated interlayer swelling behavior. Herein, we used metadynamics (MTD) molecular dynamics (MD) simulation to explore the swelling free-energy profiles for layered GO structures immersed in solvents. The stable spacings have been simulated for layered GOs in typical solvents, which appears to be quite consistent with experimental results. The effects of surface oxidization degrees and initial water contents on the GO swelling behavior have been investigated. The simulation results can be applied to elucidate the diverse experimental results. Our research provides thermodynamic insight into the swelling behavior of GO-layered structures in solvent media.

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Thermally Reduced Graphene Oxide Membrane with Ultrahigh Rejection of Metal Ions’ Separation from Water

Cited by 35 publications

References 46 publications

Electrochemical Cleaning of Fouled Laminar Graphene Membranes

Electrochemical Cleaning of Fouled Laminar Graphene Membranes

Fast Reduced Graphene-Based Membranes with High Desalination Performance

Molecular Simulation on Thermodynamic Swelling Behavior of Bilayer Graphene Oxide in Solvents

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