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    Carbon black-intercalated reduced graphene oxide electrode with graphene oxide separator for high-performance supercapacitor

    , Article Journal of Nanostructures ; Volume 9, Issue 4 , 2019 , Pages 639-649 ; 22517871 (ISSN) Jeddi, H ; Rasuli, R ; Ahadian, M. M ; Mehrabi, B ; Sharif University of Technology
    University of Kashan  2019
    Abstract
    We present a general study on a high performance supercapacitor based on intercalated reduced graphene oxide with carbon black nanoparticles. Graphene oxide sheets were synthesized by oxidation and exfoliation of natural graphite and were reduced using hydroiodic acid in the presence of carbon black nanoparticles. Graphene paper was fabricated by one-step procedure via simultaneous reducing and drying the aqueous solution of mixed carbon black nanoparticles and graphene oxide on a conductive substrate. Transmission electron microscopy confirmed the intercalation of carbon black nanoparticles into reduced graphene oxide sheets, preventing them from restacking during the fabrication of paper.... 

    Pd-WO3/reduced graphene oxide hierarchical nanostructures as efficient hydrogen gas sensors

    , Article International Journal of Hydrogen Energy ; Volume 39, Issue 15 , 15 May , 2014 , Pages 8169–8179 Esfandiara, A. (Ali) ; Iraji Zada, A. (Azam) ; Akhavana, O. (Omid) ; Ghasemic, S. (Shahnaz) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Abstract
    Pd–WO3 nanostructures were incorporated on graphene oxide (GO) and partially reduced graphene oxide (PRGO) sheets using a controlled hydrothermal process to fabricate effective hydrogen gas sensors. Pd–WO3 nanostructures showed ribbon-like morphologies and Pd–WO3/GO presented an irregular nanostructured form, while Pd–WO3/PRGO exhibited a hierarchical nanostructure with a high surface area. Gas sensing properties of thin films of these materials were studied for different hydrogen concentrations (from 20 to 10,000 ppm) at various temperatures (from room temperature to 250 °C). Although adding GO in the Pd–WO3, after hydrothermal process could increase the film conductivity, gas sensitivity... 

    Photoluminescence and electrochemical investigation of curcumin-reduced graphene oxide sheets

    , Article Journal of the Iranian Chemical Society ; Volume 15, Issue 2 , February , 2018 , Pages 351-357 ; 1735207X (ISSN) Hatamie, S ; Ahadian, M. M ; Iraji zad, A ; Akhavan, O ; Jokar, E ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    This paper reports on a novel low-temperature method for preparing curcumin-reduced graphene oxide (Cur-rGO) from graphene oxide (GO) and investigates their cyclic voltammetry (CV) and photoluminescence (PL) properties. GO sheets were synthesized using modified Hummers’ method and then were chemically reduced using polyphenol curcumin into graphene sheets. Atomic force microscopy, transmission electron microscopy and x-ray photoelectron spectroscopy were used to confirm the formation of Cur-rGO and revealed their functionalization with polyphenol curcumin. The electrochemical and optical properties of the Cur-rGO sheets were investigated using CV and PL spectroscopy. According to the PL and... 

    A new SnS2-BiFeO3/reduced graphene oxide photocatalyst with superior photocatalytic capability under visible light irradiation

    , Article Journal of Photochemistry and Photobiology A: Chemistry ; Volume 359 , 2018 , Pages 11-22 ; 10106030 (ISSN) Bagherzadeh, M ; Kaveh, R ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Herein, we report the preparation of SnS2 nanoflakes decorated with bismuth ferrite (BiFeO3) nanoparticles and reduced graphene oxide (rGO) nanosheets. The crystal structures and morphology results of composite indicated that spherical BiFeO3 nanoparticles were homogeneously attached onto the surface of SnS2 nanoflakes with the decoration of rGO sheets. The optimized photocatalyst, i.e. SnS2 (1.5)-BiFeO3/rGO (0.15) composite not only exhibites the highest photocatalytic performance for the degradation of methylene blue (MB) and Methyl orange (MO) as model reaction under visible light illumination among the individual SnS2 and BiFeO3 photocatalysts but also retains the stable photodegradation... 

    Magnetically recoverable TiO2/SiO2/γ-Fe2O3/rGO composite with significantly enhanced UV-visible light photocatalytic activity

    , Article Molecules ; Volume 25, Issue 13 , 2020 Kaveh, R ; Mokhtarifar, M ; Bagherzadeh, M ; Lucotti, A ; Diamanti, M. V ; Pedeferri, M ; Sharif University of Technology
    MDPI AG  2020
    Abstract
    In this paper, we report the preparation of a new composite (TiO2/SiO2/γ-Fe2O3/rGO) with a high photocatalytic efficiency. The properties of the composite were examined by different analyses, including X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), UV-Visible light diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, vibrating-sample magnetometer (VSM), and nitrogen gas physisorption (BET) studies. The photocatalytic efficiency of the proposed composite was evaluated by the degradation of methylene blue under UV and visible light, and the results were compared with titanium dioxide (TiO2), where... 

    Reduced graphene oxide: An alternative for Magnetic Resonance Imaging contrast agent

    , Article Materials Letters ; Volume 233 , 2018 , Pages 363-366 ; 0167577X (ISSN) Enayati, M ; Nemati, A ; Zarrabi, A ; Shokrgozar, M. A ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Graphene oxide (GO) has never been considered as a Magnetic Resonance Imaging (MRI) contrast agent since it was conceived as a diamagnetic material. There is a possibility that introduction of structural defects or manipulation of oxygen functionalities in GO change its magnetic response and provided a chance for GO to be a contrast agent for MRI. For this purpose, reduced graphene oxide (RGO) was treated by irradiation and annealing procedures. The study on the magnetic properties of the samples confirmed that the competition between the structural defects and oxygen functionalities to magnetic moments determines the magnetism in RGO. © 2018  

    Enzymatic biosensing by covalent conjugation of enzymes to 3D-networks of graphene nanosheets on arrays of vertically aligned gold nanorods: application to voltammetric glucose sensing

    , Article Microchimica Acta ; Volume 185, Issue 3 , 2018 ; 00263672 (ISSN) Mazaheri, M ; Simchi, A ; Aashuri, H ; Sharif University of Technology
    Springer-Verlag Wien  2018
    Abstract
    The authors demonstrate efficient direct electron transfer from the enzyme glucose oxidase to vertically aligned gold nanorods with a diameter of ~160 nm and a length of ~2 μm that are covalently linkage to a 3-dimensional network of reduced graphene oxide nanosheets. The assembly can be prepared by a 2-step electrochemical procedure. This hybrid structure holds the enzyme in a favorable position while retaining its functionality that ultimately provides enhanced performance for enzymatic sensing of glucose without utilizing mediators. The nanorod assembly was applied to the voltammetric detection of glucose. Figures of merit include an electrochemical sensitivity of 12 μA·mM−1·cm−2... 

    On the role of γ-Fe2 O3 nanoparticles and reduced graphene oxide nanosheets in enhancing self-cleaning properties of composite Tio2 for cultural heritage protection

    , Article Coatings ; Volume 10, Issue 10 , 2020 , Pages 1-20 Mokhtarifar, M ; Kaveh, R ; Ormellese, M ; Bagherzadeh, M ; Diamanti, M. V ; Pedeferri, M ; Sharif University of Technology
    MDPI AG  2020
    Abstract
    The durability of novel metallic artifacts and buildings is an open issue, and the role of smart protecting coatings in extending these artifacts’ lifetimes is crucial. In this paper, the role of γ-Fe2 O3 nanoparticles and reduced graphene oxide (rGO) nanosheets on enhancing the self-cleaning properties of composite TiO2 films and reducing metal alterations due to contact with acid rain and pollutants is investigated. The photocatalytic assessment of the TiO2 based films indicates that there are optimum contents for γ-Fe2 O3 and rGO, which confer the film lower bandgap and tune the TiO2 anatase/rutile ratio. By adding a proper content of γ-Fe2 O3, wettability is reduced both in dark and... 

    Reduced graphene oxide–melamine formaldehyde as a highly efficient platform for needle trap microextraction of volatile organic compounds

    , Article Microchemical Journal ; Volume 157 , 2020 Dorabadi Zare, F ; Allahdadlalouni, M ; Baktash, M. Y ; Bagheri, H ; Sharif University of Technology
    Elsevier Inc  2020
    Abstract
    A superhydrophobic extractive phase was prepared and packed in a needle trap microextraction device for extraction of volatile organic compounds, followed by their determination by gas chromatography. The superhydrophobic phase was prepared by surface modification of melamine formaldehyde (MF) sponge embedded by reduced graphene oxide (rGO). The overall properties of the modified MF along with its high sorption capacity and low cost fabrication were indicative of its feasibility to be highly suitable for extraction of organic pollutants. The determined water contact angle (>150o) from the surface of melamine formaldehyde–reduced graphene oxide (MF–rGO) revealed its high affinity toward... 

    Corrosion Resistance of Graphene-Titania Coating on 316 Stainless Steel by Electrophoretic Deposition

    , M.Sc. Thesis Sharif University of Technology Parvizi, Sahar (Author) ; Afshar, Abdollah (Supervisor)
    Abstract
    The aim of this thesis was creating Titania/RGO coating with electrophoretic method to evaluate the corrosion resistance of stainless steel 316. At first Graphene Oxide were synthesized with modified Hammers method and their physical, chemical and morphological properties have been investigated using XRD, FTIR, EDX, TGA, UV-Vis and Raman analysis. then Graphene Oxide was added to the bath of titanium and was deposited on 316 stainless steel substrates. Moreover, corrosion protection of coating has been examined using Poarization test and Electrochemical Impedance Spectrometry. The effect of deposition parameters on corrosion properties of composite coatings were examined. The key variables... 

    Curcumin-reduced graphene oxide sheets and their effects on human breast cancer cells

    , Article Materials Science and Engineering C ; Volume 55 , 2015 , Pages 482-489 ; 09284931 (ISSN) Hatamie, S ; Akhavan, O ; Sadrnezhaad, S. K ; Ahadian, M. M ; Shirolkar, M. M ; Wang, H. Q ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Curcumin (as a natural reductant material) was utilized for green reduction and functionalization of chemically exfoliated graphene oxide (GO) sheets. The π-π attachment of the curcumin molecules onto the curcumin-reduced graphene oxide (rGO) sheets was confirmed by Raman and Fourier transform infrared spectroscopies. Zeta potential of the GO sheets decreased from about - 40 mV to - 20 mV, after the green reduction and functionalization. The probable cytotoxicity of the curcumin-rGO sheets was studied through their interactions with two human breast cancer cell lines (MDA-MB-231 and SKBR3 cell lines) and a normal cell line (mouse fibroblast L929 cell line). The curcumin-rGO sheet with... 

    One-step fabrication of electrochemically reduced graphene oxide/nickel oxide composite for binder-free supercapacitors

    , Article International Journal of Hydrogen Energy ; Volume 41, Issue 39 , 2016 , Pages 17496-17505 ; 03603199 (ISSN) Shahrokhian, S ; Mohammadi, R ; Asadian, E ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    A three-dimensional (3D) graphene/Nickel oxide (ERGO/NiO) composite electrode have been fabricated directly on a Nickel foam substrate via a one-step electrochemical co-deposition in an aqueous solution containing Nickel nitrate and GO. By using this simple and one-step electrochemical deposition, it is possible to produce binder-free composite electrodes with improved electrochemical properties using a low-cost, facile and scalable technique. It is observed from FE-SEM images that graphene oxide sheets affect the electrodeposition of nickel oxide. The optimized ErGO/NiO electrode developed in this work exhibits high charge storage capacity with a specific capacitance of 1715.5 F g−1 at... 

    Polyacrylamide-grafted magnetic reduced graphene oxide nanocomposite: preparation and adsorption properties

    , Article Colloid and Polymer Science ; 2019 ; 0303402X (ISSN) Pourjavadi, A ; Nazari, M ; Kohestanian, M ; Hosseini, S. H ; Sharif University of Technology
    Springer Verlag  2019
    Abstract
    Magnetic reduced graphene oxide/polymer nanocomposites were prepared by in situ polymerization and grafting of polyacrylamide on the surface of functionalized magnetic reduced graphene oxide (rGO). Graphene oxide nanosheets were decorated with Fe3O4 nanoparticles, reduced and functionalized with 3-(trimethoxysilyl)propyl methacrylate, and then grafted with polyacrylamide. Grafting of polyacrylamide makes magnetic rGO hydrophilic and highly water dispersible. The prepared material was used as adsorbent for removal of an anionic dye, Congo red, and a maximum adsorption capacity up to 166.7 mg g−1 was obtained. The kinetics and isotherm of adsorption and the effect of experimental condition on... 

    An innovative chemometric approach for simultaneous determination of polycyclic aromatic hydrocarbons in oil-contaminated waters based on dispersive micro-solid phase extraction followed by gas chromatography

    , Article Microchemical Journal ; Volume 159 , 2020 Saburouh, N ; Jabbari, A ; Parastar, H ; Sharif University of Technology
    Elsevier Inc  2020
    Abstract
    In the present study, an analytical strategy was developed using reduced graphene oxide (rGO) as an effective sorbent in dispersive micro-solid phase extraction (DMSPE) for simultaneous determination of seven polycyclic aromatic hydrocarbons (PAHs) combined with gas chromatography (GC-FID). rGO was synthesized using modified Hummer's method and characterized using scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectroscopy. A rotatable central composite design (CCD) combined with multiple linear regression (MLR) and analysis of variance (ANOVA) was used for designing, modelling and optimization of the extraction procedure. In this regard, principal component... 

    LDPE/EVA/graphene nanocomposites with enhanced mechanical and gas permeability properties

    , Article Polymers for Advanced Technologies ; Volume 26, Issue 9 , 2015 , Pages 1083-1090 ; 10427147 (ISSN) Tayebi, M ; Ramazani S. A ; Hamed Mosavian, M. T ; Tayyebi, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2015
    Abstract
    In the present work, graphene oxide (GO) and reduced graphene oxide (RGO) were incorporated at low-density polyethylene (LDPE)/ethylene vinyl acetate (EVA) copolymer blend using solution casting method. Monolayer GO with 1-nm thickness and good transparency was synthesized using the well-known Hummers's method. Fourier transform infrared and X-ray photoelectron spectroscopy data exhibited efficient reduction of GO with almost high C/O ratio of RGO. Scanning electron microscopy showed the well distribution of GO and RGO within LDPE/EVA polymer matrix. The integrating effects of GO and RGO on mechanical and gas permeability of prepared films were examined. Young's modulus of nanocomposites are... 

    Improving the mechanical behavior of the adhesively bonded joints using RGO additive

    , Article International Journal of Adhesion and Adhesives ; Volume 70 , 2016 , Pages 277-286 ; 01437496 (ISSN) Marami, G ; Adib Nazari, S ; Faghidian, S. A ; Vakili Tahami, F ; Etemadi, S ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    In this research, Araldite 2011 has been reinforced using different weight fractions of Reduced Graphene Oxide (RGO). Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses were conducted and it has been shown that introduction of the RGO greatly changes the film morphology of the neat adhesive. Uni-axial tests were carried out to obtain the mechanical characteristics of the adhesive-RGO composites. It has been observed that introducing 0.5 wt% RGO enhances the ultimate tensile strength of the composites by 30%. In addition, single lap joints using neat adhesive and adhesive-RGO composites were fabricated to... 

    Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone

    , Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 842-850 ; 09284931 (ISSN) Shahrokhian, S ; Naderi, L ; Ghalkhani, M ; Sharif University of Technology
    Abstract
    The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force... 

    Preparation and characterization of a new CdS–NiFe2O4/reduced graphene oxide photocatalyst and its use for degradation of methylene blue under visible light irradiation

    , Article Research on Chemical Intermediates ; Volume 44, Issue 10 , 2018 , Pages 5953-5979 ; 09226168 (ISSN) Bagherzadeh, M ; Kaveh, R ; Ozkar, S ; Akbayrak, S ; Sharif University of Technology
    Abstract
    In this paper, CdS nanoparticles as a visible light active photocatalyst were coupled by NiFe2O4 and reduced graphene oxide (rGO) to form CdS–NiFe2O4/rGO nanocomposite by facile hydrothermal methods. The CdS–NiFe2O4/rGO nanocomposite shows enhanced photocatalytic activity for the degradation of methylene blue (MB) under visible light illumination. In addition to improved photocatalytic performance, this prepared nanocomposite shows increased photostability and is magnetically separable from the aqueous media. The degradation rate constant (kapp) of the optimized photocatalyst, i.e. CdS–NiFe2O4 (0.05)/rGO 25 wt% nanocomposite, was higher than the corresponding CdS and NiFe2O4 nanoparticles by... 

    Synthesis of Titanium Dioxide-graphene Nanocomposite: Characterization and Photocatalyst Applications

    , M.Sc. Thesis Sharif University of Technology Malakooti Tehrani, Shahin (Author) ; Mohammadi, Mohammad Reza (Supervisor)
    Abstract
    TiO2 and TiO2-Graphene have been synthesized by hydrothermal method. Their physical, chemical and morphological properties have been investigated using XPS, XRD, FTIR, TEM, EDX, UV-Vis and AFM analyses. Moreover, photocatalytic efficiency of prepared materials has been examined using degradation of methylene blue. AFM image exhibited that monolayer GO with thickness of 10 nm was synthesized using modified Hummer’s method. FTIR analysis represented main characteristic peak of oxygen bond on the surface of GO, whereas for TiO2-Graphene most of oxygen functionalities on the surface were removed partially or completely. Photocatalytic degradation of MB proved this extension of light absorption.... 

    Production and Properties of Reduced Graphene Oxide- Zinc Nanocomposite Coating on Steel

    , M.Sc. Thesis Sharif University of Technology Moshgi Asl, Somayyeh (Author) ; Afshar, Abdollah (Supervisor)
    Abstract
    In this project, graphene oxide was produced by chemical method (modified hummers method) because of simplicity and reproductiblity in the manufacuring process. Zinc nanoparticles were produced from pure zinc anode in the graphene oxide solution (anodic dissolution). Nanocomposite coating of reduced graphene oxide – zinc was created by electrochemical reduction with voltage pulse. Optimization of corrosion current density of the coating was done by design of experiments software (central composite design). To achieve this goal, several parameters such as cycles of zinc dissolution, frequency, duty cycle, total time of coating and applied voltage were examined. Using analysis of variance...