scholarly journals Facile Synthesis of Reduced Graphene Oxide/Fe3O4 Nanocomposite Film

2017 ◽  
Vol 15 (1_suppl) ◽  
pp. 1-6 ◽  
Author(s):  
Cunqing Ma ◽  
Kaiyu Yang ◽  
Lili Wang ◽  
Xin Wang
Keyword(s):  
Magnetic Properties ◽  
Graphene Oxide ◽  
Composite Film ◽  
Reduced Graphene Oxide ◽  
Colloidal Solution ◽  
Electronic Conductivity ◽  
Simple Method ◽  
X Ray ◽  
Blending Method ◽  
Reduced Graphene

Background This study aims at proposing a facile method to prepare rGO/Fe3O4 composite film with adjusted magnetic properties and electronic conductivity. Methods Colloidal solution of graphene oxide (GO)/Fe3O4 nanoparticles (F-NPs) with a size in the range of 20-80 nm were prepared by a solution-blending method and heated step-by-step from room temperature to 60°C, 120°C and 160°C for 12 hours, respectively, to obtain a reduced graphene oxide (rGO)/F-NP composite film. The structure, morphology, components, magnetic properties and electrical conductivity of the composite films were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, superconducting quantum interference devices and 4-probe instrument. Results The results indicated that the F-NPs were uniformly distributed on the graphene film, and the composite exhibited good ferromagnetic properties and conductivity, which could be adjusted easily via different loadings of F-NPs. A high content of F-NPs (200 mg) led to a strong saturation magnetization of 63.6 emu·g−1, with a coercivity of about 104.9 oersted (Oe). Whereas a high conductivity of 6.5 S·m−1was obtained at low amounts of F-NPs (40 mg). Notably, rGO/Fe3O4 composite film fabricated by this simple method is widely used in various fields including magnetoelectronics, electrochemical energy conversion and storage, and magnetic nanodevices and others. Conclusions A graphene-based film deposited by Fe3O4 nanoparticles with controllable loadings has been fabricated by a step-by-step heating treatment of GO/Fe3O4 colloidal solution.

Simplified Synthesis of 3D Flexible Reduced Graphene Oxide-Wrapped NiCo2O4 Nanowires for High-Performance Supercapacitor

2018 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Chao Pan ◽  
Hongyu Sun ◽  
Jingyi Gao ◽  
Yucai Hu ◽  
Jing Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Current Density ◽  
Three Dimensional ◽  
Simple Method ◽  
X Ray ◽  
Reduced Graphene

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

scholarly journals Properties of Graphene-Thermoplastic Polyurethane Flexible Conductive Film

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 400
Author(s):  
Yuehui Wang ◽  
Zhimin Zhou ◽  
Jiahao Zhang ◽  
Jinyuan Tang ◽  
Peiyu Wu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Graphene Oxide ◽  
Composite Film ◽  
Reduced Graphene Oxide ◽  
Thermoplastic Polyurethane ◽  
Mass Content ◽  
Conductive Films ◽  
Conductive Film ◽  
Blending Method ◽  
Reduced Graphene

Flexible conductive films were prepared via a convenient blending method with thermoplastic polyurethane (TPU) as matrix and nanocrystalline cellulose (NCC) modified chemically reduced graphene oxide (RGO/NCC) as the conductive fillers. The relationships between the electrical and thermal properties as well as the tensile strength and electrothermal response performance of the composite film and the mass content of reduced graphene oxide (RGO) and the initial TPU concentration were systematically investigated. The experimental results show that the resistivity of the composite film with the mass content of RGO/NCC of 7 wt% and an initial TPU concentration of 20 wt% is the minimum of 8.1 Ω·mm. However, the thermal conductivity of composite film with mass content of RGO/NCC of 5 wt% and the initial TPU concentration of 30 wt% reaches a maximum of 0.3464 W·m−1·K−1, which is an increase of 56% compared with pure TPU. The tensile strength of the composite films with mass contents of RGO of 3 wt% prepared with the initial TPU concentrations of 20 wt% reaches the maximum of 43.2 MPa, which increases by a factor of 1.5 (the tensile strength of the pure TPU is 28.9 MPa). The composite conductive film has a fast electrothermal response. Furthermore, superhydrophobic composite conductive films were prepared by immersing the composite conductive film into fluorinated decyl polyhedral oligomeric silsesquioxane (F-POSS) ethanol solution. The water contact angle of the superhydrophobic composite conductive film reaches 158.19° and the resistivity of the superhydrophobic composite film slightly increases and still has good conductivity.

scholarly journals Simultaneous Determination of Uric Acid and Xanthine Using a Poly(Methylene Blue) and Electrochemically Reduced Graphene Oxide Composite Film Modified Electrode

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Gen Liu ◽  
Wei Ma ◽  
Yan Luo ◽  
Deng-ming Sun ◽  
Shuang Shao
Keyword(s):  
Methylene Blue ◽  
Uric Acid ◽  
Graphene Oxide ◽  
Composite Film ◽  
Simultaneous Determination ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

Poly(methylene blue) and electrochemically reduced graphene oxide composite film modified electrode (PMB-ERGO/GCE) was successfully fabricated by electropolymerization and was used for simultaneous determination of uric acid (UA) and xanthine (Xa). Based on the excellent electrocatalytic activity of PMB-ERGO/GCE, the electrochemical behaviors of UA and Xa were studied by cyclic voltammetry (CV) and square wave voltammetry (SWV). Two anodic sensitive peaks at 0.630 V (versus Ag/AgCl) for UA and 1.006 V (versus Ag/AgCl) for Xa were given by CV in pH 3.0 phosphate buffer. The calibration curves for UA and Xa were obtained in the range of 8.00 × 10−8~4.00 × 10−4 M and 1.00 × 10−7~4.00 × 10−4 M, respectively, by SWV. The detection limits for UA and Xa were3.00×10-8 M and5.00×10-8 M, respectively. Finally, the proposed method was applied to simultaneously determine UA and Xa in human urine with good selectivity and high sensitivity.

Facile one pot microbe-mediated in situ synthesis and antibacterial activity of reduced graphene oxide-silver nanocomposite

2021 ◽  
Author(s):  
Ashwini Patil
Keyword(s):  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Zeta Potential ◽  
Reduced Graphene Oxide ◽  
In Vitro Dissolution ◽  
Size Analysis ◽  
X Ray ◽  
Reduced Graphene

Abstract The present research deals with the development of a novel bioinspired in situ fabrication of reduced graphene oxide (rGO)-silver nanoparticle (AgNPs) nanocomposite (rGO@AgNCs) using microbes namely Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). The fabricated rGO@AgNCs were characterized using Ultraviolet-visible (UV) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), particle size analysis, polydispersity index (PDI), zeta potential analysis, energy dispersive X-ray analysis (EDAX), Raman spectroscopy, powder X-ray diffraction (PXRD), high-resolution transmission electron microscopy (HR-TEM) analysis, etc. Furthermore, the rGO@AgNCs-PA and rGO@AgNCs-SA interaction with serum protein, pH stability study, and in vitro dissolution of AgNPs were also performed. The research findings of the proposed study demonstrated the simultaneous reduction of graphene oxide (GO) and AgNPs and the formation of rGO@AgNCs in the presence of microbes. The in vitro dissolution studies of rGO@AgNCs composites showed better AgNPs dissolution with controlled release and offered remarkable matrix integrity throughout the dissolution period. The size and stability of rGO@AgNCs-PA and rGO@AgNCs-SA had no significant changes at physiological pH 7.4. A minimal decrease in the zeta potential of rGO@AgNCs was observed, which may be due to the weak interaction of nanocomposites and albumin. The antibacterial application of the synthesized nanocomposite was evaluated against a pathogenic mastitis-forming bacterium. The obtained results suggested an admirable antibacterial activity of synthesized nanocomposites against the tested microbes. This knowledge will assist the scientific fraternity in designing novel antibacterial agents with enhanced antibacterial activity against various veterinary pathogens in near future.

Improved electronic and magnetic properties of reduced graphene oxide films

2012 ◽  
Vol 97 (3) ◽  
pp. 38001 ◽  
Author(s):  
Ross McIntosh ◽  
Messai A. Mamo ◽  
Brice Jamieson ◽  
Saibal Roy ◽  
Somnath Bhattacharyya
Keyword(s):  
Magnetic Properties ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Oxide Films ◽  
Electronic And Magnetic Properties ◽  
Reduced Graphene
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