Graphene Oxide Nanoribbons Research Articles

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.

Electrochemiluminescent immunoassay for insulin by using a quencher pair consisting of CdS:Eu nanoclusters loaded with multiwalled carbon nanotubes on reduced graphene oxide nanoribbons and gold nanoparticle-loaded octahedral Cu2O

A sensitive electrochemiluminescence (ECL) immunosensor was constructed for detection of insulin. It is based on the quenching effect of octahedral cuprous oxide decorated with gold nanoparticles (Cu2O@Au NPs). A composite constructed from multiwalled carbon nanotubes/reduced graphene oxide nanoribbons provides a large specific surface that promotes electron transfer on the surface of electrodes. In parallel, CdS nanoclusters were loaded with europium(III) to get CdS:Eu NCs. The Eu(III) ions exert a large enhancement in ECL intensity of the CdS NCs. Cu2O is biocompatible and has a large specific surface. It was used as a quencher for the ECL immunosensor. If Au NPs are loaded onto Cu2O, the green fluorescence of the CdS NCs (with emission peaks at 525nm) is quenched. The Cu2O@Au NPs also can be employed as a label for the secondary antibodies (Ab2) to improve the sensitivity of the ECL immunosensor. The assay works in the 0.5pg·mL-1 to 50ng·mL-1 insulin concentration range and has a detection limit of 40 fg·mL-1. Graphical abstract The multiwalled carbon nanotubes/reduced graphene oxide nanoribbons (MWCNT/rGONRs-CdS: Eu NCs) was used as substrate. Europium(III) (Eu3+) improves the ECL intensity of CdS NCs. The synergistic effect between Cu2O and Au NPs decreases the electrochemiluminescence of MWCNTs/rGONRs-CdS:Eu NCs.

Fabrication of electrochemical nanosensor based on carbon paste electrode modified with graphene oxide nano-ribbons and 3-(4′-amino-3′-hydroxy-biphenyl-4-yl)-acrylic acid for simultaneous detection of carbidopa and droxidopa

Bulk modification of carbon paste electrode (CPE) with graphene oxide nanoribbon and 3-(4′-amino-3′-hydroxy-biphenyl-4-yl) -acrylic acid (3,4′-AA-GONR/CPE) was used to develop a new electro-chemical sensor for sensitive determination of droxidopa and carbidopa at physiological pH. Chronoamperometry, differential pulse voltammetry, and cyclic voltammetry were employed to evaluate electro-chemical responses of as-prepared modified electrodes. A linear dependence of oxidation peak current on the concentration of droxidopa within a range between 0.02 and 300.0 μM was also observed with determination limit of 10.0 nM (S/N = 3). Desirable reproducibility, stability, and selectivity were seen in as-prepared 3,4′-AA-GONR/CPE, implying hopeful uses for concurrent detection of droxidopa and carbidopa.

Thiolated Graphene Oxide Nanoribbons as Templates for Anchoring Gold Nanoparticles: Two-Dimensional Nanostructures for SERS.

Graphene oxide nanoribbons (GONRs), obtained from the oxidative unzipping of carbon nanotubes, have been investigated as building blocks towards reaching active platforms in surface-enhanced Raman scattering (SERS). The complete development of carbon nanomaterials is strongly related to the exploitation of their chemical versatility, so this work is focused on the positive effect that a specific chemical functionalization provides to the SERS effect when gold nanoparticles are used. The covalent derivatization of GONRs with terminal thiol groups boosts their interaction with different types of gold nanoparticles (namely, 'naked' or citrate-stabilized), and the resulting two-dimensional aggregates show an intense enhancement of the Raman scattering from the carbon nanostructures because of their two-dimensional extended aggregation pattern. The SERS effect has been corroborated by theoretical calculations and a conceptual proof of SERS-based sensing.

Solid/liquid phase microextraction of five bisphenol-type endocrine disrupting chemicals by using a hollow fiber reinforced with graphene oxide nanoribbons, and determination by HPLC-PDA.

A novel solid/liquid phase microextraction (SLPME) technique was developed and applied to the simultaneous determination of five bisphenol-type endocrine disrupting chemicals (EDCs) including bisphenol A, bisphenol S, bisphenol F, bisphenol B and bisphenol AF. The method is based on the use of agraphene oxide nanoribbon-reinforced hollow fiber (GONRs-HF) and 1-octanol. GONRs were longitudinally unzipped from multiwalled carbon nanotubes (MWCNTs) by means of chemical oxidation and carefully characterized. GONRs were dispersed in ultrapure water with the assistance of surfactant and then immobilized into the wall pores of HF. Compared with CNTs, the hydrophilicity of GONRs was improved, and a uniform dispersion was formed. This simplifies the preparation process and reduces waste of materials. The pores and lumen of GONRs-HF were filled with 1-octanol, and then the whole assembly was used for the extraction of the analytes. In comparison with different extraction modes, GONRs-HF-SLPME exhibits a more effective extraction performance for five bisphenol-type EDCs. Response surface methodology was used to optimize experimental parameters affecting the extraction efficiency. The enrichment factors are in the range from 76 to 127 with good inter-fiber and batch-to-batch reproducibility. The method shows good linearity with determination coefficients (R2) higher than 0.9985. The limits of detection are in the range of 0.1-0.4μgL-1. Recoveries from spiked real samples are between 83% and 114% with relative standard deviations between 1.6% and 7.8%. Graphical abstract Schematic presentation of the preparation of graphene oxide nanoribbons (GONRs) with multiwalled carbon nanotubes (MWCNTs), immobilization of GONRs into the pores of hollow fiber (HF), and application for solid/liquid phase microextraction (SLPME) of five bisphenol-type endocrine disrupting chemicals in three kinds of real samples.

Dependence of reduction degree on electromagnetic absorption of graphene nanoribbon unzipped from carbon nanotube

Carbon materials are very promising for electromagnetic wave absorption application due to their light weight and low cost, where the reflection loss is used to evaluate the absorption efficiency. However, the reflection loss of carbon materials (carbon foam, graphene, and carbon nanotube) without loading magnetic particles is not as high as expected. Here, we propose to unzip carbon nanotubes into graphene oxide nanoribbons (GONRs), followed by controllable reduction treatment using hydrazine hydrate, and the reduced GONRs were finalized (called as r-GONRs). The r-GONRs exhibit obvious dielectric relaxation behaviors compared to GONRs, and the dielectric loss is improved by increasing the reduction degree. The optimized r-GONRs show ultrahigh electromagnetic absorption, up to −65.09 dB at a thickness of 2 mm, which is more advantageous than the reported values of other carbon materials. The efficient absorption bandwidth (reflection loss ≤−10 dB) reaches 7.06 GHz. These are attributed to the large dielectric loss of the unique graphene nanoribbon. Our controllable reduced graphene nanoribbon is promising in the application of radar wave absorption and electromagnetic shielding.

Realization of Ambient-Stable Room-Temperature Ferromagnetism by Low-Temperature Annealing of Graphene Oxide Nanoribbons.

Graphene oxide nanoribbons (GONRs) annealed at the low temperature of 400 °C (aGONRs-400) are developed as an excellent room-temperature (RT) ferromagnet. The saturated magnetization ( Ms) of aGONRs-400 is high, up to 0.39 emu/g at room temperature, and the RT ferromagnetism (FM) exhibits excellent ambient stability with Ms preserved for over half a year. The preferential distribution of the magnetic phenolic hydroxyl toward the edges, which contributes to the long-range ferromagnetic couplings, was confirmed by X-ray photoemission spectroscopy measurement and gradient annealing analysis. The approach of low-temperature annealing is proved to be efficient both to remove the prominent nonmagnetic epoxy groups on the basal plane of GONRs or transform them to magnetic hydroxyl groups and to preserve the magnetic phenolic hydroxyl at the edges to realize a strong and ambient stable FM.

Graphene oxide nanoribbons for ethanol detection at room temperature

Gas detection area has been the subject of intense research due to its importance for human life and environment. In this study, Graphene oxide nanoribbons (GONRs) are synthesized by chemical unzipping method. These GONRs are used for fabrication of the sensor for ethanol molecules detection, which have a chemical adsorption with GONRs. In the fabrication process, Au is deposited by DC magnetron sputtering as an electrode material. The prearranged pattern is an interdigitated electrode created by the standard photolithography process. Different characterizations such as Raman spectroscopy, SEM, and UV–vis analysis are performed to be sure about that the GONR structure and morphology are carefully implanted before using it as a sensing material. The obtained results exhibit that the synthesis process is carried out successfully. All the experiments are carried out at room temperature, without sensor warming up and additional catalyst. Finally, the tests are performed for concentration range between 100–680 ppm and the response and sensitivity of a sensor are surveyed. It is determined that the fabricated device has a desirable responsibility and sensitivity to ethanol. Experimental results show that the sensitivity is 4.4% for 100 ppm.

Electrochemical Properties of Graphene Oxide Nanoribbons/Polypyrrole Nanocomposites

Graphene is a highly studied material due to its unique electrical, optical, and mechanical properties. Graphene is widely applied in the field of energy such as in batteries, supercapacitors, and solar cells. The properties of graphene can be further improved by making nanocomposites with conducting polymers. In this work, graphene oxide nanoribbons (GONRs) were synthesized by unzipping multiwall carbon nanotubes. Graphene nanoribbons were used to make nanocomposites with polypyrrole for energy storage applications. The synthesized nanocomposites were structurally and electrochemically characterized to understand their structure and electrochemical properties. The electrochemical characterizations of these nanocomposites were carried out using cyclic voltammetry. The specific capacitance of the nanocomposites was observed to decrease with increasing scan rates. The highest specific capacitance of 2066 F/g was observed using cyclic voltammetry for the optimized nanocomposite of GONR and polypyrrole. Our study suggests that the electrochemical properties of graphene or polypyrrole can be improved by making their composites and that they could be successfully used as electrode materials for energy storage applications. This study can also be extended to the self-assembly of other conducting polymers and graphene nanoribbons through a simple route for various other applications.

Two-dimensional graphene oxide-reinforced porous biodegradable polymeric nanocomposites for bone tissue engineering.

This study investigates the mechanical properties and in vitro cytotoxicity of two-dimensional (2D) graphene oxide nanoribbons and nanoplatelets (GONRs and GONPs) reinforced porous polymeric nanocomposites. Highly porous poly(propylene fumarate) (PPF) nanocomposites were prepared by dispersing 0.2 wt % single- and multiwalled SONRs (SWGONRs and MWGONRs) and GONPs. The mechanical properties of scaffolds were characterized using compression testing and in vitro cytocompatibility was assessed using QuantiFlour assay for cellularity and PrestoBlue assay for cell viability. Immunofluorescence was used to assess collagen-I expression and deposition in the extracellular matrix. Porous PPF scaffolds were used as a baseline control and porous single and multiwalled carbon nanotubes (SWCNTs and MWCNTs) reinforced nanocomposites were used as positive controls. Results show that incorporation of 2D graphene nanomaterials leads to an increase in the mechanical properties of porous PPF nanocomposites with following the trend: MWGONRs > GONPs > SWGONRs > MWCNTs > SWCNTs > PPF control. MWGONRs showed the best enhancement of compressive mechanical properties with increases of up to 26% in compressive modulus (i.e., Young's modulus), ~60% in yield strength, and ~24% in the ultimate compressive strength. Addition of 2D nanomaterials did not alter the cytocompatibility of porous PPF nanocomposites. Furthermore, PPF nanocomposites reinforced with SWGONRs, MWGONRs, and GONPs show an improvement in the adsorption of collagen-I compared to PPF baseline control. The results of this study show that 2D graphene nanomaterial reinforced porous PPF nanocomposites possess superior mechanical properties, cytocompatibility, and increased protein adsorption. The favorable cytocompatibility results opens avenues for in vivo safety and efficacy studies for bone tissue engineering applications. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1143-1153, 2019.

Room temperature ammonia gas sensor based on Au/graphene nanoribbon

Graphene nanoribbon (GNR) is a strip and 1D shape of graphene which can be an appropriate candidate for gas sensing application due to its significant electrical and chemical characteristic. In this study, graphene nanoribbon is employed for the NH3 detection process. The chemical approach is applied for unzipping MWCNTs by using KMnO4, as an oxidative material in graphene oxide nanoribbon synthesis process. The gold comb-like electrodes as a sensor structure is produced by standard deposition and photolithography methods. The quality of the synthesized GNRs is investigated by different analyses such as SEM, XRD, Raman Spectroscopy, and FTIR. In addition to GNR sensor preparation, AuGNR sensor is fabricated by gold sputtering deposition on a GNR sensor surface. The experimental results for sensors indicate that AuGNR and GNR sensors could be the appropriate choices for NH3 detection. The experimental tests for AuGNR and GNR sensors are performed for different NH3 concentration at room temperature which showed 34% and 12.1% response for 25 ppm NH3 respectively. Furthermore, in 25 ppm for the AuGNR sensor, the sensor shows 224 s for response time, and 178 s for recovery time for a graphene-based sensor. All the tests are carried out at room temperature.

Thorium adsorption on graphene oxide nanoribbons/manganese dioxide composite material

A functional graphene oxide nanoribbons/manganese dioxide composite material (MnO2-GONRs) was synthesized by hydrothermal method using graphene oxide nanoribbons (GONRs) as raw material which were formed by longitudinal unzipping of multi-walled carbon nanotubes with KMnO4 and H2SO4. The microstructure of MnO2-GONRs was characterized by SEM and FT-IR. The various factors affecting the adsorption of Th(IV) in aqueous solution such as pH, solid–liquid ratio, contact time, initial concentration and temperature were investigated by batch static adsorption experiments, and the adsorption mechanism is also discussed. The results showed that MnO2-GONRs had a good adsorption effect on Th(IV) with a maximum adsorption of 166.11 mg/g.

An Ultrasensitive Electrochemical Sensor Based on Multiwalled Carbon Nanotube@Reduced Graphene Oxide Nanoribbon Composite for Simultaneous Determination of Hydroquinone, Catechol and Resorcinol

Three dihydroxybenzene isomers, hydroquinone (HQ), catechol (CC) and resorcinol (RS), were determined simultaneously by an ultrasensitive electrochemical sensor based on a glassy carbon electrode modified by multiwalled carbon nanotube@reduced graphene oxide nanoribbon (MWCNT@rGONR) composite. The material was synthesized via hydrothermal method and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). We used cyclic voltammetry (CV) to study the electrochemical performance of the three isomers and differential pulse voltammetry (DPV) to optimize the experimental parameters. Based on the optimal experimental condition, our electrochemical sensor displayed a good linear relationship with the concentration range of 15 to 921 μM, 15 to 1101 μM, and 15 to 1301 μM and detection limit of 3.89 μM, 1.73 μM and 5.77 μM for HQ, CC and RS respectively. The electrochemical sensor based on MWCNT@GONR composite showed outstanding ability of reproducibility, stability and anti-interference. In addition, this sensor was also used successfully for simultaneous determination of HQ, CC and RS in real samples with satisfactory result.

Design of mechanically stable, electrically conductive and highly hydrophobic three-dimensional graphene nanoribbon composites by modulating the interconnected network on polymer foam skeleton

The development of three-dimensional (3D) graphene nanoribbon (GNR) based porous composites with both mechanical reliability and multiple functionality has attracted great interest due to their promising applications in strain sensing, oil/water separation, etc. Herein, we report a facile strategy to fabricate robust porous 3D GNR wrapped polymer foam composites through modulating an interconnected GNR network and introducing a flexible polydimethylsiloxane (PDMS) coating. By simply adjusting the graphene oxide nanoribbon (GONR) concentration in aqueous solution followed by chemical reduction, the presence of the reduced GONR (rGONR) sheets endows commercial polyurethane (PU) foam with electrical conductivity without altering their porous microstructure. The mechanical properties of the rGONR-coated PU (PGR) foam composites depend strongly on the rGONR content and exhibit poor stability at low content due to the breakage of the rGONR network during cyclic deformation. Introduction of the flexible PDMS coating effectively stabilizes the 3D rGONR network on the foam skeleton, producing excellent mechanical reliability, e.g., reversible compressibility at a compressive strain of 80% for 100 cycles. Moreover, these mechanically stable and porous PDMS modified PGR composites display excellent lipophilic-hydrophobic behavior, which provides good oil/solvent absorption capacity and highly efficient continuous oil/water separation.

Synthesis of magnetic graphene oxide nanoribbons composite for the removal of Th(IV) from aqueous solutions

Functionalized magnetic graphene oxide nanoribbons (MGONRs) composite material was synthesized by hydrothermal treatment method using graphene oxide nanoribbons as raw material, which was formed by longitudinal unzipping of multi-walled carbon nanotubes in oxidizing environment. The morphology and structural properties of MGONRs were characterized by SEM, FT-IR, XRD and VSM and thorium adsorption behavior on MGONRs was investigated. The results showed that thorium adsorption on MGONRs was pH-dependent, endothermic and spontaneous. The adsorption process followed pseudo-second order and Freundlich isotherm model with rapid solid–liquid separation. MGONRs could have practical application in separation and recovery of thorium from aqueous solutions.

A Sensitive Resonance Rayleigh Scattering Method for Na+ Based on Graphene Oxide Nanoribbon Catalysis.

The gold nanoparticle reaction of HAuCl4-H2O2 was very slow under 60°C, and the as-prepared graphene oxide nanoribbons (GONRs) exhibited strong catalysis of the reaction to form gold nanoparticles (AuNP) that appeared a resonance Rayleigh scattering (RRS) peak at 550 nm. Upon addition of potassium pyroantimonate (PA) ligand, it was adsorbed on the GONRs surface to inhibit the catalysis to cause the RRS peak decreasing. When the analyte of Na+ was added, the coordination reaction between PA and Na+ took place to form the stable complexes of [Na2(PA)] to release free GONRs catalyst that resulted in the RRS peak increasing linearly. Accordingly, a new and sensitive RRS method for Na+ was established, with a linear range of 0.69-25.8 nmol/L and a detection limit of 0.35 nmol/L Na+.

Fabrication of a Mo-Doped Strontium Cobaltite Perovskite Hybrid Supercapacitor Cell with High Energy Density and Excellent Cycling Life.

Enriched with oxygen vacancies, Mo-doped strontium cobaltite (SrCo0.9 Mo0.1 O3-δ , SCM) is synthesized as an oxygen anion-intercalated charge-storage material through the sol-gel method. The supplemented oxygen vacancies, good electrical conductivity, and high ion diffusion coefficient bestow the SCM electrode with excellent specific capacitance (1223.34 F g-1 ) and specific capacity (168.88 mAh g-1 ) at 1 A g-1 . The decisive constant (b-value) deduced for the charge storage mechanism (low scan-rate region) is nearly 0.8, indicating a highly capacitive process. In the high scan-rate region, however, the b-value is almost 0.5, and a linear pattern of charge (q) versus the inverse of the square root of the scan rate (v-1/2 ) is obtained. The results reveal O2- diffusion as the rate-limiting factor for charge storage. Furthermore, a hybrid cell (SCM∥LRGONR) is fabricated by using lacey, reduced graphene oxide nanoribbon (LRGONR) as the negative electrode, which exhibits a high energy density (74.8 Wh kg-1 at a power density of 734.5 W kg-1 ). With a charging time of only 20.7 s, the cell sustains a very high energy density (33 Wh kg-1 ) with a high power delivery rate (6600 W kg-1 ). The excellent cycling stability (165.1 % activated specific capacitance retention and 97.6 % of the maximum value attained) after 10 000 charge-discharge cycles, demonstrates SCM is a potential electrode material for supercapacitors.

Enhanced electrochemical performance of anion-intercalated lanthanum molybdenum oxide pseudocapacitor electrode

Metal oxides with oxygen vacancies can be exploited as a charge storage material for supercapacitor. This work demonstrates synthesis of lanthanum molybdenum oxide (La2Mo2O9, LMO) using different calcination temperatures (300, 400, 500, 600 and 700 °C). As prepared LMO500 illustrates its utilization as an anion intercalated material for supercapacitors. Among all LMOs, LMO500 electrode exhibits high gravimetric (727.18 F g−1 at 0.5 A g−1) and areal (290.87 mF cm−2 at 0.5 A g−1) capacitance. The superior electrochemical performance of LMO500 can be attributed to complete transformation of its mixed phases (i.e. oxides, hydroxides) to its pure oxides (β-La2Mo2O9). Due to existence of pure phase, devoid of secondary phases, LMO500 exhibits good electron kinetics which affords low charge transfer resistance. The asymmetric supercapacitor (LMO500‖LRGONR) employing lacey reduced graphene oxide nanoribbons (LRGONR) as negative electrode delivers high energy density of 52 Wh kg−1 at a power density of 474 W kg−1 which is more than twice of symmetric cell (LMO500‖LMO500). Other than high energy and power density, LMO500‖LRGONR cell shows 98.74% capacitance retention after 1000 GCD cycles at 1.0 A g−1, endorsing excellent cycle stability.

High performance non-enzymatic graphene-based glucose fuel cell operated under moderate temperatures and a neutral solution

Abstract In this study, a non-enzyme glucose fuel cell is assembled and shows high energy density in neutral solution at moderate temperature. The anodic material, graphene sheets grafted with platinum and palladium (PtPd/G), is prepared by polyol method to oxidize glucose. The cathode material, nitrogen-doped graphene oxide nanoribbons (NGONR) is prepared by a microwave process, and shows great oxygen reduction capability in neutral cerebrospinal fluid (CSF) solution. After cell assembly, test results show that the performance of the glucose fuel cell is significantly affected by oxygen concentration, glucose concentration and operating temperature. Compared with the enzyme glucose fuel cell, the non-enzyme glucose fuel cell can generate power not only at room or human body temperatures, but within a temperature range from 5 to 80 °C. The cell power density increases with increasing operating temperature. The assembled fuel cell can produce a maximum power density of 24.9 µW/cm2 in a neutral 10 mM CSF and 8 mM glucose solution at 80 °C with an oxygen purge flow.

A new SERS strategy for quantitative analysis of trace microalbuminuria based on immunorecognition and graphene oxide nanoribbon catalysis.

BackgroundMicroalbuminuria (mAlb) detection is essential for the diagnosis and prognosis of nephrotic patients and hypoproteinemia. In this article, we develop a new surface-enhanced Raman scattering (SERS) quantitative analysis method to detect mAlb in urine.MethodsCombined the mAlb immunoreaction with gold nanoreaction of graphene oxide nanoribbons (GONR)-HAuCl4-H2O2, and used Victoria blue B (VBB) as molecular probe with a SERS peak at 1,615 cm−1, a new SERS strategy for quantitative analysis of trace mAlb in urine was established.ResultsThe linear range of SERS quantitative analysis method is from 0.065 to 2.62 ng/mL, with a detection limit of 0.02 ng/mL. The SERS method was applied to analysis of mAlb in urine with good accuracy and reliability, the relative standard deviation is 0.49%–2.28% and the recovery is 96.9%–109.8%.ConclusionThis study demonstrated that the new SERS quantitative analysis method is of high sensitivity, good selectivity and simplicity. It has been applied to analysis of mAlb in urine, with satisfactory results.