A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

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Nonenzymatic Electrochemical Immunosensor Using Ferroferric Oxide–Manganese Dioxide–Reduced Graphene Oxide Nanocomposite as Label for α-Fetoprotein Detection

NANO ◽

10.1142/s1793292016501162 ◽

2016 ◽

Vol 11 (10) ◽

pp. 1650116 ◽

Cited By ~ 5

Author(s):

Wensi Jian ◽

Chunping Wang ◽

Zuanguang Chen ◽

Yanyan Yu ◽

Duanping Sun ◽

...

Keyword(s):

Graphene Oxide ◽

Manganese Dioxide ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Low Cost ◽

Synergetic Effect ◽

Electrochemical Immunosensor ◽

Quantitative Detection ◽

Ferroferric Oxide ◽

Reduced Graphene

A novel nonenzymatic electrochemical immunosensor was fabricated for quantitative detection of [Formula: see text]-fetoprotein (AFP). The immunosensor was constructed by modifying gold electrode with electrochemical reduction of graphene oxide-carboxyl multi-walled carbon nanotube composites (ERGO–CMWCNTs) and electrodeposition of gold nanoparticles (AuNPs) for effective immobilization of primary antibody (Ab[Formula: see text]. Ferroferric oxide–manganese dioxide–reduced graphene oxide nanocomposites (Fe3O4@MnO2–rGO) were designed as labels for signal amplification. On one hand, the excellent electroconductivity and outstanding electron transfer capability of ERGO–CMWCNTs/AuNPs improved the sensitivity of the immunosensor. On the other hand, introduction of rGO could not only increase the specific surface area for immobilization of secondary antibody (Ab[Formula: see text] but also build a synergetic effect to reinforce the electrocatalytic properties of catalysts. Fe3O4@MnO2–rGO nanocomposites were characterized by scanning electron microscope, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Using AFP as a model analyte, the proposed sandwich-type electrochemical immunosensor exhibited a wide linear range of 0.01–50[Formula: see text][Formula: see text] with a low detection limit of 5.8[Formula: see text][Formula: see text]. Moreover, the Fe3O4@MnO2–rGO-based peroxidase mimetic system displayed an excellent analytical performance with low cost, satisfactory reproducibility and high selectivity, which could be further extended for detecting other disease-related biomarkers.

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Determination of Trace Lead and Cadmium in Decorative Material Using Disposable Screen-Printed Electrode Electrically Modified with Reduced Graphene Oxide/L-Cysteine/Bi-Film

Sensors ◽

10.3390/s20051322 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1322 ◽

Cited By ~ 2

Author(s):

Xiaopeng Hou ◽

Benhai Xiong ◽

Yue Wang ◽

Li Wang ◽

Hui Wang

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Electrochemical Impedance ◽

Low Cost ◽

Linear Sweep Voltammetry ◽

Differential Pulse ◽

Screen Printed Electrode ◽

Lead And Cadmium ◽

Reduced Graphene ◽

Screen Printed

Cadmium (Cd) and lead (Pb) in decorative materials threaten human health. To determine the content of Cd(II) and Pb(II), a disposable screen-printed electrode (DSPE) electrically modified with reduced graphene oxide (rGO) and L-cysteine (LC) was fabricated, which was further electroplated with bismuth film (Bi/LC-rGO/DSPE) in situ. The electrochemical properties of this electrode were studied using cyclic voltammetry, electrochemical impedance spectroscopy, linear sweep voltammetry and differential pulse voltammetry. The results indicated that the Bi/LC-rGO/DSPE had excellent sensitivity, selectivity and stability with low cost and easy production. After optimizing the detection parameters, the linear range of the Bi/LC-rGO/DSPE was from 1.0 to 30.0 μg/L for Cd(II) and Pb(II), and the detection limits were 0.10 μg/L for Cd(II) and 0.08 μg/L for Pb(II). Finally, the Bi/LC-rGO/DSPE was applied to determine the concentrations of Cd(II) and Pb(II) in different decorative materials where the recoveries were in the range from 95.86% to 106.64%.

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Reduced Graphene Oxide Using an Environmentally Friendly Banana Extracts

MRS Advances ◽

10.1557/adv.2019.280 ◽

2019 ◽

Vol 4 (38-39) ◽

pp. 2143-2151

Author(s):

Lattapol Buasuwan ◽

Vitchayes Niyomnaitham ◽

Aniwat Tandaechanurat

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Large Scale ◽

Chemical Reduction ◽

Environmentally Friendly ◽

Reducing Agents ◽

Banana Peel ◽

Chemical Exfoliation ◽

Reduced Graphene

ABSTRACTOne of the most promising methods to produce graphene in large scale is the use of chemical exfoliation together with chemical reduction to achieve reduced graphene oxide. Replacing conventional reducing agents, such as NaBH4 and hydrazine, with cheap, widely available, safe, environmentally friendly, and easy-to-prepare reducing agents is a key to large-scale commercial production of reduced graphene oxide. In this work, we investigate the effectiveness of utilizing fruit extracts derived from banana peel and juice to reduce graphene oxide. After the reduction, the oxygen-containing functional groups in graphene oxide are effectively removed, and the sp2 hybridized carbon-carbon bonding networks are restored, as evidenced by the characterization using x-ray photoelectron spectroscopy and Raman spectroscopy. Our banana extracts would offer a promising pathway for realizing cheap, safe, and environmentally friendly reducing agents for the upscale production of reduced graphene oxide.

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Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

REVIEWS ON ADVANCED MATERIALS SCIENCE ◽

10.1515/rams-2020-0022 ◽

2020 ◽

Vol 59 (1) ◽

pp. 207-214 ◽

Cited By ~ 1

Author(s):

Yao Wang ◽

Jianqing Feng ◽

Lihua Jin ◽

Chengshan Li

Keyword(s):

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Low Cost ◽

Photocatalytic Reduction ◽

Force Microscopy ◽

Atomic Force ◽

Reduced Graphene ◽

Reduction Efficiency ◽

Metal Organic ◽

Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

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Self-supported 3D reduced graphene oxide for solid-phase extraction: An efficient and low-cost sorbent for environmental contaminants in aqueous solution

Talanta ◽

10.1016/j.talanta.2021.122750 ◽

2021 ◽

pp. 122750

Author(s):

Raimara de Souza Gomes ◽

Anderson Thesing ◽

Jacqueline Ferreira Leite Santos ◽

Andreia Neves Fernandes

Keyword(s):

Aqueous Solution ◽

Graphene Oxide ◽

Solid Phase Extraction ◽

Reduced Graphene Oxide ◽

Solid Phase ◽

Low Cost ◽

Environmental Contaminants ◽

Phase Extraction ◽

Reduced Graphene

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Boron from net charge acceptor to donor and its effect on hydrogen uptake by novel Mg-B-electrochemically synthesized reduced graphene oxide

Scientific Reports ◽

10.1038/s41598-021-90531-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marla V. V. Satya Aditya ◽

Srikanta Panda ◽

Sankara Sarma V. Tatiparti

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Incubation Time ◽

Photoelectron Spectroscopy ◽

Weight Ratio ◽

Hydrogen Uptake ◽

Binding Energies ◽

Unit Cell ◽

Net Charge ◽

Reduced Graphene

AbstractHydrogen uptake (H-uptake) is studied in ball milled Mg-B-electrochemically synthesized reduced graphene oxide (erGO) nanocomposites at PH2 ≈ 15 bar, ~ 320 °C. B/C (weight ratio): 0, ~ 0.09, ~ 0.36, ~ 0.90 are synthesized maintaining erGO≈10wt %. B occupies octahedral interstices within Mg unit cell—revealed by electron density maps. Persistent charge donations from Mg and B to C appear as Mg-C (~ 283.2 eV), B-C (~ 283.3–283.9 eV) interactions in C-1s core X-ray photoelectron spectroscopy (XPS) at all B/C. At B/C > 0.09, charge reception by B from Mg yields Mg-B interaction. This net charge acceptor role of B renders it electron-rich and does not alter Mg unit cell size significantly. Despite charge donation to both C and B, the Mg charge is < + 2, resulting in long incubation times (> 5 h) at B/C > 0.09. At B/C≈0.09 the minimal Mg-B interaction renders B a charge donor, resulting in Mg-B repulsion and Mg unit cell expansion. Mg-C peak shift to lower binding energies (C-1s XPS), decreases incubation time to ~ 2.25 h and enhances H-uptake kinetics. Various atomic interactions influence the reduction of incubation time in H-uptake and increase its kinetics in the order: (Mg → C; B → C)B/C≈0.09, B: donor > (Mg → C)B/C=0 > (ternary Mg → B → C)B/C>0.09, B: acceptor.

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Chemically reduced graphene oxide-coated knitted fabric imparted conductivity and outstanding hydrophobicity

Textile Research Journal ◽

10.1177/0040517521995471 ◽

2021 ◽

pp. 004051752199547

Author(s):

Min Hou ◽

Xinghua Hong ◽

Yanjun Tang ◽

Zimin Jin ◽

Chengyan Zhu ◽

...

Keyword(s):

Electrical Conductivity ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Chemical Reduction ◽

Knitted Fabric ◽

Mesh Structure ◽

Reduced Graphene ◽

Chemically Reduced Graphene Oxide ◽

Modified Hummers Method

Functionalized knitted fabric, as a kind of flexible, wearable, and waterproof material capable of conductivity, sensitivity and outstanding hydrophobicity, is valuable for multi-field applications. Herein, the reduced graphene oxide (RGO)-coated knitted fabric (polyester/spandex blended) is prepared, which involves the use of graphite oxide (GO) by modified Hummers method and in-situ chemical reduction with hydrazine hydrate. The treated fabric exhibits a high electrical conductivity (202.09 S/cm) and an outstanding hydrophobicity (140°). The outstanding hydrophobicity is associated with the morphology of the fabric and fiber with reference to pseudo-infiltration. These properties can withstand repeated bending and washing without serious deterioration, maintaining good electrical conductivity (35.70 S/cm) and contact angle (119.39°) after eight standard washing cycles. The material, which has RGO architecture and continuous loop mesh structure, can find wide use in smart garment applications.

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