Graphene Oxide Nanoribbons Research Articles

Preparation of graphene/graphene nanoribbons hybrid aerogel and its application for the removal of uranium from aqueous solutions

Graphene/graphene nanoribbons hybrid aerogel (GA/GNRs) was prepared via a hydrothermal process by using graphene oxide as precursor, and the graphene oxide nanoribbons unzipped from multi-walled carbon nanotubes were compound together. Various techniques were used to investigate the morphology, surface properties and structure of aerogel samples. Besides, the adsorption properties of the hybrid aerogel for the removal of U(VI) were further studied. The results showed that GNRs was grafted on the surface of graphene, and the specific surface area and porous pores structure were enhanced. The adsorption process of hybrid aerogel for U(VI) was pH-dependent, rapid, spontaneous and endothermic, and the maximum adsorption capacity for U(VI) was calculated to be 327.8 mg/g, which is expected to separate uranium from wastewater.

A nanostructured porous carbon/MoO2 composite with efficient catalysis in polysulfide conversion for lithium–sulfur batteries

Lithium–sulfur batteries are considered as the next generation of energy storage systems because of their high theoretical specific capacity and energy density. Unfortunately, the sluggish reaction kinetics, weak adsorption toward to lithium polysulfides, and slow lithium ion diffusion impede the smooth electrochemical process, resulting in the lithium–sulfur batteries with the unsatisfactory cycling stability and rate performance. Since it is recognized that polar metal oxides and doped nitrogen in carbon materials have chemical interaction with lithium polysulfides, a nanostructured nitrogen-doped porous carbon/MoO2 composite is synthesized through a simple hydrothermal method by using graphene oxide nanoribbon and phosphomolybdic acid hydrate as precursors. The porous nanostructure promotes the charge and mass transport, while MoO2 nanoparticles immobilize lithium polysulfides via strong chemisorption and enhance the redox kinetics of polysulfides owing to the efficient catalytic activity in liquid–solid boundary. Consequently, the as-obtained nanostructured porous carbon/MoO2-based sulfur cathode exhibits low polarization, high initial discharge capacity (1403 mAh g−1 at 0.1 C), good rate capabilities (584 mAh g−1 at 4 C), and impressive cycling performance at 1 C (503 mAh g−1 after 500 cycles with capacity fade rate of 0.07% per cycle).

Synthesis of Graphene Nanoribbons–Hydroxyapatite Nanocomposite Applicable in Biomedicine and Theranostics

In order to investigate the effect of graphene nanoribbons on the final properties of hydroxyapatite-based nanocomposites, a solvothermal method was used at 180 °C and 5 h for the synthesis of graphene nanoribbons–hydroxyapatite nanopowders by employing hydrogen gas injection. Calcium nitrate tetrahydrate and diammonium hydrogenphosphate were used as calcium and phosphate precursors, respectively. To synthesize the powders, a solvent containing diethylene glycol, anhydrous ethanol, dimethylformamide, and water was used. Graphene oxide nanoribbons were synthesized by chemical unzipping of carbon nanotubes under oxidative conditions. The synthesized powders were consolidated by spark plasma sintering methodat 950 °C and a pressure of 50 MPa. The powders and sintered samples were then evaluated using X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, Vickers microindentation techniques, and biocompatibility assay. The findings of this study showed that the final powders synthesized by the solvothermal method had calcium to phosphate ratio of about 1.67. By adding a small amount of graphene nanoribbon (0.5%W), elastic modulus and hardness of hydroxyapatite increased dramatically. In biological experiments, the difference of hydroxyapatite effect in comparison with the nanocomposite was not significant. The findings of this study showed that graphene nanoribbons have a positive effect on the properties of hydroxyapatite, and these findings would be useful for the medical and theranostic application of this type of nanocomposites.

Ammonium decavanadate nanodots/reduced graphene oxide nanoribbon as “inorganic-organic” hybrid electrode for high potential aqueous symmetric supercapacitors

The issue of relatively low operating potential window in aqueous supercapacitors is usually conquered by fabrication of asymmetric devices. To achieve the same in symmetric cells, electrodes with high electrochemical activity and wide working potential are needed. Herein, we report a strategy to extend the operating potential by utilizing ammonium decavanadate-holey reduced graphene oxide nanoribbons (rGONR-ADV) as hybrid electrode for supercapacitors. Besides high charge storage, use of redox-active ADV in hybrid provides a large overpotential towards water reduction, enabling wide potential window. The nano hybrids are synthesized at three different temperatures (140 °C, 160 °C, 180 °C) where rGONR-ADV 160 shows unsurpassed performance (1186 F g−1 @ 1 A g−1) owing to the optimized synergistic effect, highly electroactive surface area and improved ionic diffusion. The rGONR-ADV 160‖rGONR-ADV 160 cell displays high specific capacitance (406 F g−1 @ 0.5 A g−1), decent cycling stability (83% after 5000 cycles) with high energy/power density (120.2 Wh kg−1 and 1624.14 W kg−1). Interestingly, this device works well up to 1.5 V in 1 M H2SO4 i.e. well beyond thermodynamic limit of water decomposition. Present study illustrates the performance of polyoxometalates based hybrid electrode for high potential aqueous supercapacitors and energy density for practical applications.

Electrochemical determination of sulfamethazine using a gold electrode modified with multi-walled carbon nanotubes, graphene oxide nanoribbons and branched aptamers.

An aptasensor assay for sulfamethazine isintroduced based on agold electrode modified with multi-walled carbon nanotubes@graphene oxide nanoribbons (MWCNTs@GONRs) nanocomposites. The MWCNTs@GONRs nanocomposites were synthesized by achemical longitudinal partially unzipping method. Its properties are characterized by scanning electron microscope (SEM), energy dispersive spectrometric analysis (EDS), transmission electron microscope (TEM) and X-ray diffraction (XRD). In the presence of sulfamethazine, the conformation of theaptamer changes and aG-quadruplex structure isformed. It inhibits the electron transfer of the redox probe [Fe(CN)6]3-/4- on the electrode surface, causing weakening ofthe peak current response at the peak potential of 0.17V (vs. Ag/AgCl). Usingdifferential pulse voltammetry, a linear response was obtained forsulfamethazine concentrations in the range 0.01 ~ 50ngmL-1 with a detection limit of5.2pgmL-1. Graphical abstract Schematic representation of an electrochemical aptasensor for sulfamethazine determination. A gold electrode is modified with multi-walled carbon nanotubes@graphene oxide nanoribbons to improve the electrode performance. When the aptamer binds to sulfamethazine to form G-quadruplex, the peak current response decreases.

One-dimensional graphene for efficient aqueous heavy metal adsorption: Rapid removal of arsenic and mercury ions by graphene oxide nanoribbons (GONRs)

There is a knowledge gap for the application of one-dimensional graphene in the adsorption process. Our hypothesis was based on the fact that graphene oxide nanoribbons (GONRs) as one-dimensional graphene with more desired edges and specific surface area than other carbonaceous nanomaterials have more oxygen containing functional groups (active sites) on their edges and basal planes and therefore are more capable in adsorption of pollutants. In this regard, we synthesized GONRs by unzipping of multi-walled carbon nanotubes (MWCNTs) and investigated the adsorption behavior of GONRs by ultrasonic-assisted adsorptive removal of As(V) and Hg(II) ions from aqueous solution. The obtained results showed that As(V) ions are more favorably adsorbed onto the GONRs than Hg(II) ions and with increasing initial As(V) and Hg(II) ions concentration to 300 ppm, the equilibrium adsorption uptake of the synthesized GONRs increases to 155.61 and 33.02 mg/g for As(V) and Hg(II) ions, respectively through a rapid separation process in just 12 min. Also, three kinetic models and Freundlich and Langmuir adsorption isotherms were applied to evaluate the obtained experimental results. Our findings highlight the potential application of GONRs as one-dimensional graphene adsorbent with more desired edges than MWCNTs and graphene oxide (GO) and high adsorption capacity for selective removal of heavy metals.

Graphene Oxide Nanoribbons in Chitosan for Simultaneous Electrochemical Detection of Guanine, Adenine, Thymine and Cytosine.

Herein, graphene oxide nanoribbons (GONRs) were obtained from the oxidative unzipping of multi-walled carbon nanotubes. Covalent coupling reaction of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxy succinimide (NHS) with amine functional groups (-NH2) of the chitosan natural polymer (CH) was used for entrapping GONRs on the activated glassy carbon electrode (GCE/GONRs-CH). The nanocomposite was characterized by high-resolution transmission electron microscopy (HRTEM), and field-emission scanning electron microscopy (FESEM). In addition, the modification steps were monitored using FTIR. The nanocomposite-modified electrode was used for the simultaneous electrochemical determination of four DNA bases; guanine (G), adenine (A), thymine (T) and cytosine (C). The nanocomposite-modified GCE displayed a strong, stable and continuous four oxidation peaks during electrochemistry detection at potentials 0.63, 0.89, 1.13 and 1.27 V for G, A, T and C, respectively. The calibration curves were linear up to 256, 172, 855 and 342 μM with detection limits of 0.002, 0.023, 1.330 and 0.641 μM for G, A, T and C, respectively. The analytical performance of the GCE/GONRs-CH has been used for the determination of G, A, T and C in real samples and obtained a recovery percentage from 91.1%–104.7%. Our preliminary results demonstrated that GCE/GONRs-CH provided a promising platform to detect all four DNA bases for future studies on DNA damage and mutations.

Rheological and physical properties of a nanocomposite of graphene oxide nanoribbons with polyvinyl alcohol

In this work, the physicochemical and rheological properties of a nanocomposite of graphene oxide (GO) and thermoplastic polyvinyl alcohol (PVA) are reported. After adding deionized water to PVA, the sample was heated and mixed. The polymer solution was divided in two portions, each of them containing PVA in water. GO nanoribbons were added to one portion of the PVA solution in water to obtain the nanocomposite suspension (1% w/w). The similarity of the Fourier-transform infrared spectra of PVA and its related nanocomposite was assessed (both having similar peaks, an important observation as it indicated the water absorption on the samples). The scanning electron microscopy images showed that PVA lost its spherical shape in composites due to the GO sheets coating. The characteristic peaks O− ( m/ e 16) and OH− ( m/ e 17) were observed in the time-of-flight secondary ion mass spectrometry negative mode spectra of PVA and nanocomposite of GO nanoribbons with PVA. The analysis of the OH−, O−, C2H−, and C2− peaks of PVA and the nanocomposite of GO nanoribbons revealed that a reduction occurred for GO nanoribbons when coated with PVA. The rheological behaviors of samples in solution were studied and their shear rate versus shear stress were assessed. A non-Newtonian rheological behavior of the nanocomposite of GO nanoribbons with PVA was observed. The dielectric response of the nanocomposite of GO-PVA featured a simultaneous increase of both real and imaginary part of the complex permittivity toward low frequency due to the contribution of charge carriers. These results provide more understanding about the physical, mechanical, and dielectric properties of GO-PVA nanocomposite to make it appropriate in the construction of embedded capacitors. The novelty of our work lies in the rheological and physical properties of this nanocomposite in comparison with those of PVA that have not been previously reported.

Antioxidant Graphene Oxide Nanoribbon as a Novel Whitening Agent Inhibits Microphthalmia-Associated Transcription Factor-Related Melanogenesis Mechanism.

In the melanin synthesis process, oxidative reactions play an essential role, and it is a good strategy to inhibit melanin production by reducing oxidative stress. Fullerene and its derivatives, or the complexes, were considered as strong free-radical scavengers, and we further applied multilayered sp2 nanocarbons to discover melanin synthesis inhibitory mechanisms. In the present study, we used novel nanomaterials, such as multiwalled carbon nanotubes (MWCNTs), short-type MWCNTs, graphene oxide nanoribbons (GONRs), and short-type GONRs, as anti-oxidative agents to regulate melanin production. The results showed that GONRs had better anti-oxidative capabilities in intracellular and extracellular oxidative stress analysis platforms than others. We proposed that GONRs have oxygen-containing functional groups. In the 2′,7′-dichlorodihydrofluorescein diacetate assay, we found out GONR could chelate metal ions to scavenge reactive oxygen species. In the molecular insight view, we observed that these nanomaterials downregulated the melanin synthesis by decreasing microphthalmia-associated transcription factor-related gene expressions, and there were similar consequences in protein expressions. To sum up, GONRs is a potential agent as a novel antioxidant and skin-whitening cosmetology material.

In Situ Growth of Metal-Organic Framework HKUST-1 on Graphene Oxide Nanoribbons with High Electrochemical Sensing Performance in Imatinib Determination.

Metal-organic frameworks (MOFs) have been previously investigated as electrode materials for developing electrochemical sensors. They have usually been reported to suffer from poor conductivity and improvement in the conductivity of MOFs is still a great challenge. Here, we reported the fabrication of an electrochemical sensor based on the in situ growth of framework HKUST-1 on conductive graphene oxide nanoribbons (GONRs)-modified glassy carbon electrode (GCE) (HKUST-1/GONRs/GCE). The as-fabricated modified electrode was characterized using field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, Fourier transform infrared, X-ray diffraction, electrochemical impedance spectroscopy, cyclic voltammetry, and Raman spectroscopy. The voltammetric response of HKUST-1/GONRs/GCE toward Imatinib (IMA), as an anticancer drug, is dramatically higher than HKUST-1/GCE because of the synergic effect of the GONRs and HKUST-1 framework. The calibration curve at the HKUST-1/GONRs/GCE for IMA covered two linear dynamic ranges, 0.04-1.0 and 1.0-80 μmol L-1, with a detection limit of 0.006 μmol L-1 (6 nmol L-1). Taking advantage of the conductivity of GONRs and large surface area of HKUST-1, a sensitive modified electrode was developed for the electrochemical determination of IMA. The present method provides an effective strategy to solve the poor conductivity of the MOFs. Finally, the obtained electrochemical performance made this modified electrode promising in the determination of IMA in urine and serum samples.

Comparative Study of Physicochemical Properties and Antibiofilm Activity of Graphene Oxide Nanoribbons

In this article, the antibiofilm activity and physicochemical properties of graphene oxide (GO) nanoribbons, which have been among the most exciting materials, were studied by measuring the ratio of killed to alive bacteria incubated with these nanomaterials. Our objective was to determine the related physicochemical and antibiofilm properties of graphene oxide nanoribbons. We hypothesized that the physicochemical properties of graphene oxide nanoribbons could affect their antibiofilm activity. A combination of spectroscopic and microscopic measurements of the samples allowed us to determine their physicochemical properties affecting the biofilms. Our work includes information on the surface properties of these materials related to their incubation with the biofilms. The Fourier transform infrared spectroscopy showed the vibrations of OH groups of water molecules adsorbed on graphene oxide nanoribbons. The results show the high antibiofilm activity of the graphene oxide nanoribbons. The fluorescence confocal microscopy revealed that 50 % ± 3 % of the total number of bacteria were killed with these nanomaterials. The incubation of graphene oxide nanoribbons with bacterial biofilms resulted in the appearance of the NO2–, NO3– peaks in the negative mode mass spectrum. The attenuation of the O– and OH– peaks were attributed to the interactions of the samples with the biofilms. Our study gives more evidence of the practical value of graphene oxide nanoribbons in killing bacteria related to their surface physical properties and the potential of these nanomaterials for materials science and biomedical applications. Keywords: nanomaterials, bacterial biofilm, Fourier transform, infrared spectroscopy, transmission electron microscopy, time-of-flight secondary ion mass spectrometry, confocal microscopy.

A novel electrochemical aptasensor for the sensitive detection of kanamycin based on UiO-66-NH2/MCA/MWCNT@rGONR nanocomposites.

In this work, we designed and synthesized a nanocomposite comprising an amine-functionalized metal organic framework (UiO-66-NH2), a multiwalled carbon nanotube@reduced graphene oxide nanoribbon (MWCNT@rGONR) and a covalent organic framework (COF) synthesized using melamine and cyanuric acidmonomers via polycondensation (represented by MCA). The UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite was used as a sensitive platform for an electrochemical aptasensor to detect kanamycin (kana). Owing to the rich chemical functionality, amino-rich structure and excellent electrochemical activity, the cDNA strands with terminal amino groups can not only anchor over the UiO-66-NH2/MCA/MWCNT@rGONR surface but also penetrate into the interior of porous UiO-66-NH2/MCA/MWCNT@rGONR networks. The characterization of the UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite was performed by scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Furthermore, cyclic voltammetry (CV) and square wave voltammetry (SWV) were employed for the electrochemical performance study of this biosensor. The results indicated that the UiO-66-NH2/MCA/MWCNT@rGONR nanocomposite exhibited high bioaffinity toward the aptamer and the lowest limit of detection at 13 nM (S/N = 3) within a linearity of the kana concentration of 25-900 nM. In addition, it possessed great repeatability, stability and selectivity and obtained satisfactory recovery results in the real analysis of fish meat and milk, indicating the great potential for analytical measurements in food safety.

Core–shell structured multiwall carbon nanotube–graphene oxide nanoribbon and its N-doped variant as anodes for high-power microbial fuel cells

The MFCs with N-MWCNT@GONR and MWCNT@GONR anodes exhibits high power densities up to 3444 mW m−2 and 3291 mW m−2.

Poly(vinyl alcohol) Fibers with Excellent Mechanical Properties Produced by Reinforcement of Single-walled Graphene Oxide Nanoribbons with Complete Morphology Obtained by Freeze-drying

Nanofiller reinforcement is an effective approach to realize high performance of regular synthetic fibers. In this paper, graphene oxide nanoribbons (GONRs) with complete morphology were prepared via unzipping single-walled carbon nanotubes (SWCNTs) through long-time freeze-drying after oxidation. GONRs derived from SWCNTs (SGONRs) did not need any modification and could be directly added to poly(vinyl alcohol) (PVA) to form uniform dispersions and then continuous fibers were fabricated using wet spinning and hot-drawing. SGONRs provided abundant hydrogen bonding interaction with PVA chains, so SGONRs could not only obviously improve the dispersibility in PVA, but also enhance the mechanical properties of the composites. The tensile strength of PVA/SGONRs composite fibers with 0.4 wt% loading of SGONRs reach 1032 MPa, improved by 121 % compared with PVA/SWCNTs fiber, and by 200% with PVA fiber, respectively.

Graphene oxide nanoribbon catalysis of gold nanoreaction and its application to SERS quantitative analysis of ultratrace glucose

Catalysis of four nanostructures, including graphene oxide nanoribbons (GONR), graphene oxide, N-doped carbon quantum dot and Ca-doped carbon quantum dot is examined on the reaction HAuCl4–trisodium citrate to form nanogold (AuNP). GONR exhibited strongest catalysis and appeared a SERS peak at 1615 cm−1 in the presence of Victoria blue 4R molecular probes in the formed AuNP sol substrate. Upon addition of 4-mercaptophenylboronic acid (MPBA), it adsorbs on GONR to form MPBA–GONR conjugates that caused the SERS peak decreasing due to its catalysis decreasing. Upon addition of glucose, it reacts with MPBA to form MPBA–glucose complex to increase the SERS peak linearly owing to GONR catalysis recovering. The increased SERS signal (ΔI) is linear to glucose concentration in the range of 0.33–5.33 nM, with a detection limit of 0.13 nM. Thus, a new and highly sensitive SERS quantitative analysis method is established for detection of glucose, based on GONR catalytic amplification.

High-performance nanohybrid anode based on FeS2 nanocubes and nitrogen-rich graphene oxide nanoribbons for sodium ion batteries

Sodium ion batteries (SIBs) have attracted considerable attention as an alternative to Li ion batteries (LIBs) because of the sustainable sodium resources and similar chemistry to LIBs. On the other hand, the larger and heavier sodium results in unfavorable sodium ion storage capacity. In this study, an inexpensive precursor-based conversion material, FeS2, was synthesized as a nanostructured pyrite crystal, <100 nm in size, which has a carbon coating layer, a few nanometers in thickness. The deficient electrical conductivity of the synthesized FeS2 nanocubes (FeS2-NCs) was strengthened by forming a nanohybrid structure with high-aspect ratio graphene oxide nanoribbons containing nitrogen dopants (N-GONRs). N-GONRs bind tightly the FeS2-NCs well-dispersed in the N-GONRs matrix, inducing highly improved electrochemical performance as an anode for SIBs. The FeS2-NCs/N-GONRs nanohybrid anode delivered a high reversible capacity of ∼800 mA h g−1 at 0.2 A g−1, of which approximately 60% was maintained at a 50 times higher current rate, indicating high rate capability. In addition, stable cycling performance over 200 cycles was achieved with an average capacity of ∼670 mA h g−1. The hybrid anode demonstrated its feasibility in a full cell test using an O3-type cathode material.

A novel ultrasensitive electrochemical quercetin sensor based on MoS2 - carbon nanotube @ graphene oxide nanoribbons / HS-cyclodextrin / graphene quantum dots composite film

An electrochemical quercetin (Que) sensor based on molybdenum disulfide (MoS2) - carbon nanotube @ graphene oxide nanoribbons (CNTs@GONRs) / thiol-β-cyclodextrin (HS-CD) / aminated graphene quantum dots (N-GQDs) was constructed. Portions of multi-walled carbon nanotubes (MWCNTs) were unzipped to form CNTs@GONRs, and MoS2 was successfully grown on it to form composites (MoS2-CNTs@GONRs). The obtained MoS2-CNTs@GONRs / HS-CD / GQDs nanocomposite was characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). Under optimized conditions, the proposed sensor had an excellent detection performance for Que with a wide linear range from 2.0 × 10−9 - 1.6 × 10−6 M and a lower limit of detection (LOD) of 8.2 × 10−10 M. The sensor also exhibited satisfactory stability and accuracy for Que detection in actual samples (juice and honey). The present work provided a novel method for the detection of Que and also proposed a new type of electrochemical sensing material.

All‐Solid‐State Asymmetric Supercapacitors with Metal Selenides Electrodes and Ionic Conductive Composites Electrolytes

AbstractAll‐solid‐state flexible asymmetric supercapacitors (ASCs) are developed by utilization of graphene nanoribbon (GNR)/Co0.85Se composites as the positive electrode, GNR/Bi2Se3 composites as the negative electrode, and polymer‐grafted‐graphene oxide membranes as solid‐state electrolytes. Both GNR/Co0.85Se and GNR/Bi2Se3 composite electrodes are developed by a facile one‐step hydrothermal growth method from graphene oxide nanoribbons as the nucleation framework. The GNR/Co0.85Se composite electrode exhibits a specific capacity of 76.4 mAh g−1 at a current density of 1 A g−1 and the GNR/Bi2Se3 composite electrode exhibits a specific capacity of 100.2 mAh g−1 at a current density of 0.5 A g−1. Moreover, the stretchable membrane solid‐state electrolytes exhibit superior ionic conductivity of 108.7 mS cm−1. As a result, the flexible ASCs demonstrate an operating voltage of 1.6 V, an energy density of 30.9 Wh kg−1 at the power density of 559 W kg−1, and excellent cycling stability with 89% capacitance retention after 5000 cycles. All these results demonstrate that this study provides a simple, scalable, and efficient approach to fabricate high performance flexible all‐solid‐state ASCs for energy storage.

A nanocomposite consisting of ZnO decorated graphene oxide nanoribbons for resistive sensing of NO2 gas at room temperature.

A composite prepared from zinc oxide and graphene oxide nanoribbons (ZnO/GONR) is demonstrated to enable improved room temperature (RT) detection of nitrogen dioxide (NO2). Low-cost hydrothermal synthesis is used to construct the composite. The properties of the resistive sensor, including the sensitivity, response and recovery times, repeatability and selectivity, were investigated in the NO2 concentration range from 1 to 50ppm at RT. The sensor, typically operated at a voltage of 5V, exhibits a low detection limit of 1ppm, a fast response-recovery time, and excellent repeatability which outperforms that of pure ZnO sensors. The sensing mechanism is explained in terms of a redox reaction between NO2 and oxygen anions on the surface of the ZnO/GONR composite. Graphical abstract Schematic representation of the NO2 sensing mechanisms on the surface of the ZnO/GONR composite and overall improved NO2 gas-sensing performance.

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

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.