Graphene Oxide Hybrid Composites Research Articles

Investigations on mechanical properties and stacking sequence of Kevlar/banana fiber reinforced nano graphene oxide hybrid composites

This paper focuses on the fabrication of a new hybrid polymer composite laminate (HPCL) using biodegradable materials to avoid dumping of waste and has all the desired characteristics as compared to the conventional matrix composites used in various applications such as aerospace, railways cabin, structures, sports equipment, medical field, etc. Utilizing the hand lay-up method and compression molding machine, six layers of Kevlar fiber, banana fiber, and an epoxy-based matrix reinforced with graphene oxide (GO) were fabricated. By altering the stacking order of fibers in which the HPCL were stacked and embedding GO of various weight percentages (0 wt%, 0.25 wt%, 0.50 wt%, 0.75 wt%, and 1 wt%). As a result, it was seen that the best mechanical characteristics were found to be 42.23 MPa interlaminar shear strength, flexural strength, 300.39 MPa tensile strength, and 85.68 hardness were obtained at set C-2 i.e. 0.5 wt% of GO embedded in KKBBKK stacking order. The 0.25 wt% of GO of HPCL of set C-1 yielded the impact strength with the greatest value of 771.6 J m−1. Field emission scanning electron microscopy, energy dispersive x-ray mapping and x-ray diffraction tests were also conducted for validating the homogeneity of the material. All the mechanical properties were enhanced by embedding GO and incorporating stacking order in HPCL. Therefore, HPCL can be used where lightweight material with proper mechanical strength and biodegradability is an important condition for sustainable development.

Axially coordinated tin porphyrins anchored graphene oxide hybrid composites as productive catalyst for catalytic conversion of 4-nitrophenol to 4-aminophenol

Axially coordinated tin porphyrins anchored graphene oxide hybrid composites as productive catalyst for catalytic conversion of 4-nitrophenol to 4-aminophenol

Graphene oxide hybrid with amine‐terminated poly(amidoamine) dendrimers encapsulating Pt nanoparticles for electrochemical oxygen reduction reaction

AbstractWe synthesized Pt nanoparticles using amine‐terminated poly(amidoamine) dendrimers to hybridize the nanoparticles encapsulated inside dendrimers with graphene oxide (GO) sheets. The resulting Pt–GO hybrid composites revealed improved electrocatalytic activity in oxygen reduction reaction compared with GO sheets.

Impact of an anionic surfactant on the enhancement of the capacitance characteristics of polyaniline-wrapped graphene oxide hybrid composite

Impact of an anionic surfactant on the enhancement of the capacitance characteristics of polyaniline-wrapped graphene oxide hybrid composite

Mixed‐phase MoS 2 decorated reduced graphene oxide hybrid composites for efficient symmetric supercapacitors

In this work, we demonstrated the phase-tuned MoS2 layers (2H- MoS2, 1 T- MoS2, and 2H/1 T-MoS2) using a one-pot reaction, scientifically significant due to their impermeable characteristics. Strongly-bonded, vertically-aligned layers were perceived by transmission electron microscopy (TEM) for 2H/1 T-MoS2 layers. The spacing between the two layers was expanded to 0.67 nm, which is favorable for intercalation process. Further, mixed-phase MoS2 sheets were successively blended with reduced graphene oxide (rGO) to form 2H/1 T-MoS2@rGO hybrid. Spectroscopic studies verified the formation of phase-tuned MoS2 and 2H/1 T-MoS2@rGO hybrid. The resulting 2H/1 T-MoS2@rGO hybrid TEM micrograph shows the layered MoS2 lattices decorated rGO nano-structure. Symmetric supercapacitors constructed from 2H/1 T-MoS2@rGO hybrid electrodes demonstrated improved storage capacity with solid pseudo-capacitive behavior compared to the pure phases. Surface-modified 2H/1 T-MoS2@rGO nanostructures exhibited a high energy density of 55 Wh·kg−1 at a power density of 3 kW·kg−1 with a symmetric capacitance of 275 F·g−1 at a current density of 1 A·g−1, along with an excellent cyclic constancy (~97% capacity after 5000 cycles).

Fabrication of magnesium ferrite microspheres decorated nitrogen-doped reduced graphene oxide hybrid composite toward high-efficiency electromagnetic wave absorption

In this work, magnesium ferrite (MgFe2O4) microspheres decorated nitrogen-doped reduced graphene oxide (NRGO) hybrid composite was fabricated through a solvothermal and hydrothermal two-step method. Results manifested that the three-dimensional netlike structure consisting of MgFe2O4 microspheres and crumpled NRGO was well constructed in the as-synthesized hybrid composite. Significantly, both hybridization with reduced graphene oxide (RGO) and nitrogen doping had few effects on the size of MgFe2O4 microspheres. Furthermore, the influences of hybridization with RGO, nitrogen doping and filler loadings on the electromagnetic absorption properties were carefully examined. It was found that both hybridization with RGO and nitrogen doping were effective strategies to enhance the electromagnetic absorption capacity of MgFe2O4 microspheres. Remarkably, the as-prepared NRGO/MgFe2O4 hybrid composite presented excellent electromagnetic absorption performance, that was the minimum reflection loss of −48.0 dB at 5.2 GHz, and maximum absorption bandwidth of 4.8 GHz under a low filler loading of 25.0 wt% and a small matching thickness of 2.0 mm. In addition, the potential electromagnetic absorption mechanisms were revealed. Therefore, our results could be beneficial to fabricating graphene-based dielectric/magnetic hybrid composites as high-efficiency electromagnetic absorbers.

Kombucha SCOBY-based carbon and graphene oxide wrapped sulfur/polyacrylonitrile as a high-capacity cathode in lithium-sulfur batteries

Hierarchically-porous carbon nano sheets were prepared as a conductive additive for sulfur/polyacrylonitrile (S/PAN) composite cathodes using a simple heat treatment. In this study, kombucha (that was derived from symbiotic culture of bacteria and yeast) carbon (KC) and graphene oxide (GO) were used as a carbon host matrix. These rational-designed S/PAN/KC/GO hybrid composites greatly suppress the diffusion of polysulfides by providing strong physical and chemical adsorption. The cathode delivered an initial discharge capacity of 1652 mAh·g−1 at a 0.1 C rate and a 100th cycle capacity of 1193 mAh·g−1. The nano sheets with embedded hierarchical pores create a conductive network that provide effective electron transfer and fast electrochemical kinetics. Further, the nitrogen component of PAN can raise the affinity/interaction of the carbon host with lithium polysulfides, supporting the cyclic performance. The results exploit the cumulative contribution of both the conductive carbon matrix and PAN in the enhanced performance of the positive electrode.

A one pot hydrothermal stimulated CdS-reduced graphene oxide (CdS/rGO) hybrid nanocomposite for high performance photovoltaic applications

The development of high performance and cost-effective counter electrode (CE) is a persistent objective in order to convey the quantum dot sensitized solar cell (QDSSC) from laboratories to markets benches. In this study, we fabricate a novel CdS/reduced graphene oxide hybrid composite by a one step hydrothermal method using cadmium nitrate, thiourea and graphite as raw materials. Prior to the photovoltaic study the structural, morphological and optical properties of the samples were analyzed by using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Raman, UV–Vis diffuse reflectance spectra (DRS) and Photoluminescence spectra analysis. XRD and FESEM results exhibit that cubic structure with spherical shaped morphology of CdS and particles are well dispersed on the graphene nanosheets. The surface area and pore size of CdS/rGO composite was analyzed by using N2 absorption–desorption measurements and found to be 127 m2/g and 13.51 nm respectively, which is higher than that of bare CdS (73 m2/g; 28.23 nm). We further construct the flexible photoelectrodes bys using CdS and rGO and studied the photovoltaic performance. Photovoltaic parameters, such as short-circuit photocurrent density, open circuit voltage, fill factor and conversion efficiency were found to be 9.7 mA/cm2, 0.91 V, 68.0% and 12.5% respectively, for CdS/rGO photoelectrode.

Synthesis and Characterization of Chitosan/Reduced Graphene Oxide Hybrid Composites.

Graphene family materials (GFM) are currently considered to be one of the most interesting nanomaterials with a wide range of application. They can also be used as modifiers of polymer matrices to develop composite materials with favorable properties. In this study, hybrid nanocomposites based on chitosan (CS) and reduced graphene oxide (rGO) were fabricated for potential use in bone tissue engineering. CS/rGO hydrogels were prepared by simultaneous reduction and composite formation in acetic acid or lactic acid and crosslinked with a natural agent—tannic acid (TAc). A broad spectrum of research methods was applied in order to thoroughly characterize both the components and the composite systems, i.e., X-ray Photoelectron Spectroscopy, X-ray Diffractometry, Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy, Scanning Electron Microscopy, ninhydrin assay, mechanical testing, in vitro degradation and bioactivity study, wettability, and, finally, cytocompatibility. The composites formed through the self-assembly of CS chains and exfoliated rGO sheets. Obtained results allowed also to conclude that the type of solvent used impacts the polymer structure and its ability to interact with rGO sheets and the mechanical properties of the composites. Both rGO and TAc acted as crosslinkers of the polymer chains. This study shows that the developed materials demonstrate the potential for use in bone tissue engineering. The next step should be their detailed biological examinations.

Ternary Co3O4/NiO/reduced graphene oxide hybrid composites with improved electrochemical properties

Abstract Transition metal oxides are considered to be ideal electrode materials for supercapacitors, but they usually suffer from poor conductivity and low capacitance. Herein, Co3O4 and NiO nanoparticles are decorated on reduced graphene oxide (rGO) to form ternary Co3O4/NiO/rGO composites using hydrothermal method. The study focuses on the dependence of the electrochemical properties on the molar ratio of cobalt to nickel, calcination temperature and rGO loading. Upon calcination at 400 °C, the Co3O4/NiO composites with a molar ratio of 1:3 display superior electrochemical performance. The adding of rGO to Co3O4/NiO composites can effectively enhance the dispersion of nanoparticles and improve the electrochemical performance overall. Compared with rGO and Co3O4/NiO, the high specific capacitance of 325 F/g at a current density of 0.5 A/g and good rate capability are achieved for ternary composites. The excellent electrochemical performance is probably attributed to the feature of cobalt and nickle oxides nanoparticles highly dispersed on rGO nanosheets. This can increase the electron conductivity, provide more exposed electroactive sites and facilitate the faradaic redox processes.

Hydrothermal synthesis of silver molybdate/reduced graphene oxide hybrid composite: An efficient electrode material for the electrochemical detection of tryptophan in food and biological samples

A simple and accurate electrochemical sensor for the detection of tryptophan (TRP) was developed by modifying the surface of glassy carbon electrode (GCE) with silver molybdate incorporated reduced graphene oxide (AgM/RGO) composite. The AgM/RGO composite was synthesized by single step hydrothermal synthesis. The as-prepared AgM/RGO composite was confirmed by the various analytical and spectroscopic techniques. The electrochemical properties of the AgM/RGO composite was investigated by cyclic voltammetry and amperometric method. The AgM/RGO modified GCE shows an excellent electrochemical detection towards of TRP. The combination of AgM and RGO are not only enhanced the electrochemical properties of the composite but also improved the electron transfer between the electrode and TRP. Under the optimal condition, the proposed sensor was showed a wide linear range from 0.02 to 146.96 μM with a low detection limit of 0.0057 μM. Besides, the electrode sensitivity was calculated to be 4.327 μA μM−1 cm2. Remarkably, the proposed sensor exhibited good selectivity, stability, reproducibility and repeatability. The AgM/RGO/GCE was successfully applied to TRP determination in food and biological samples.

Electrostatically Charged MoS2/Graphene Oxide Hybrid Composites for Excellent Electrochemical Energy Storage Devices.

We demonstrate, for the first time, a new method of fabricating hybrid MoS2/poly(ethyleneimine)-modified graphene oxide (PEI-GO) composites assembled through electrostatically charged interaction between the negatively charged MoS2 nanosheets and positively charged PEI-GO in an aqueous solution. The GO can not only improve the electronic conductivity of the MoS2/PEI-GO composites, leading to an excellent charge-transfer network, but also hamper the restacking of MoS2 nanosheets. The composition ratios between MoS2 and PEI-GO were also optimized with the highest specific capacitance of 153.9 F g-1 where 96.0% of the initial specific capacitance remains after 6800 cycles. The specific capacitance of only 117.5 F g-1 was observed for the pure MoS2 nanosheets, and 68.2% of the initial specific capacitance was achieved after 5000 cycles. The excellent electrochemical performance of the hybrid MoS2/PEI-GO composites was demonstrated by establishing an asymmetric supercapacitor with a MoS2/PEI-GO-based negative electrode and an activated-carbon positive electrode. The asymmetric supercapacitor provided a maximum capacitance of 42.9 F g-1, and 93.1% of the initial capacitance was maintained after 8000 cycles. Furthermore, a MoS2/PEI-GO//activated-carbon asymmetric supercapacitor delivered an energy density of 19.3 W h kg-1 and a power density of 4500 W kg-1, indicating the potential of the hybrid MoS2/PEI-GO composites in electrochemical energy storage applications.

One-Pot Facile Methodology to Synthesize Chitosan-ZnO-Graphene Oxide Hybrid Composites for Better Dye Adsorption and Antibacterial Activity.

Novel chitosan–ZnO–graphene oxide hybrid composites were prepared using a one-pot chemical strategy, and their dye adsorption characteristics and antibacterial activity were demonstrated. The prepared chitosan and the hybrids such as chitosan–ZnO and chitosan–ZnO–graphene oxide were characterized by UV-Vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The thermal and mechanical properties indicate a significant improvement over chitosan in the hybrid composites. Dye adsorption experiments were carried out using methylene blue and chromium complex as model pollutants with the function of dye concentration. The antibacterial properties of chitosan and the hybrids were tested against Gram-positive and Gram-negative bacterial species, which revealed minimum inhibitory concentrations (MICs) of 0.1 µg/mL.

Nonvolatile memory devices based on poly(vinyl alcohol) + graphene oxide hybrid composites.

Nonvolatile memory devices based on active layers of poly(vinyl alcohol) (PVA) + graphene oxide (GO) hybrid composites have been fabricated. The performance of the ITO/PVA + GO/Al device was compared with that of the ITO/PVA/Al device. The ITO/PVA + GO/Al device showed excellent performance compared to the ITO/PVA/Al device (an ON/OFF resistance ratio of 1.2 × 10(2) at 1 V, V(SET )∼ -1.45 V and V(RESET) ∼ 3.6 V), with a higher ON/OFF resistance ratio of 3 × 10(4) at 1 V and lower operating voltages of V(SET) ∼ -0.75 V and V(RESET) ∼ 3.0 V. Furthermore, endurance performance and write-read-erase-reread (WRER) cycle tests manifest that the presence of GO in ITO/PVA + GO/Al devices makes them have better stability and repeatability. The results show that the performance of hybrid devices can be effectively enhanced by the introduction of GO into the PVA matrix.

Magnetic porous silica–graphene oxide hybrid composite as a potential adsorbent for aqueous removal of p-nitrophenol

Abstract The magnetic porous silica–graphene oxide hybrid composites (Fe3O4@mSiO2/GO) were synthesized via grafting graphene oxide sheets onto the core–shell Fe3O4@mSiO2 nanoparticles, and their application in removing p-nitrophenol from aqueous solution was also investigated. The as-prepared Fe3O4@mSiO2/GO composites were characterized by transmission electron microscopy, fourier-transform infrared spectroscopy, nitrogen adsorption–desorption isotherms and vibrating sample magnetometer. The adsorption kinetics, adsorption isotherms, adsorption thermodynamics and influence of solution pH were discussed. The experimental results indicated that the adsorption process was well fitted by the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity was 1548.78 mg/g at the solution pH 8.0 and at 25 °C. The Fe3O4@mSiO2/GO hybrid composites could be easily separated from solutions through an external magnetic force. Undoubtedly the Fe3O4@mSiO2/GO hybrid composites might have a bright future in removing organic pollutants from wastewater.

Incorporation of polyaniline nanofibres on graphene oxide by interfacial polymerization pathway for supercapacitor

The aim of this work is to improve the supercapacitor performance of polyaniline (PANI). Polyaniline nano fibres are incorporated into graphene oxide (GO) layers by interfacial polymerization pathway, wherein PANI fibres are intercalated into GO layers and also cover the GO. PANI–GO hybrid composite is obtained in semi-crystalline form with good conductivity (1.7 S cm−1). The specific capacitance for PANI–GO (365 F g−1) is found to be higher than PANI (280 F g−1). At the energy density of 15 W h kg−1, the power density of PANI–GO (632 W kg−1) is higher than PANI (283 W kg−1).

Room-temperature high-performance acetone gas sensor based on hydrothermal synthesized SnO2-reduced graphene oxide hybrid composite

In this paper, we demonstrated a room-temperature acetone gas sensor based on a tin dioxide (SnO2)-reduced graphene oxide (RGO) hybrid composite film.

CoMoO4·0.9H2O nanorods grown on reduced graphene oxide as advanced electrochemical pseudocapacitor materials

In this work, one-dimensional CoMoO4·0.9H2O nanorods grown on reduced graphene oxide hybrid composites (CoMoO4·0.9H2O–rGO) with good electrochemical properties have been synthesized by a simple and environmentally friendly hydrothermal synthesis procedure. The conductive graphene not only improves the electron conductivity of the overall electrode but also provides strong synergistic effects with Faradaic pseudo-capacitance (CoMoO4·0.9H2O). Meanwhile, rGO can act as a buffer for the volume change, which can provide an assurance for better cycling performance of the CoMoO4·0.9H2O–rGO hybrid composites. An exceptionally high specific capacitance of 802.2 F g−1 at a current density of 1 A g−1 and good cycle stability with capacitance retention of ∼86.3% after 5000 cycles is obtained for the CoMoO4·0.9H2O–rGO composites. The remarkable electrochemical performance can make the CoMoO4·0.9H2O–rGO composites one of the most competitive electrode materials for electrochemical energy storage.

Sandwich-structured MnO2/polypyrrole/reduced graphene oxide hybrid composites for high-performance supercapacitors

Sandwich-structured hierarchical (MnO2, PPy)/rGO nanosheets composites exhibited a maximum specific capacitance of 404 F g−1 and ∼91% of capacitance retention over 5000 cycling.

Novel blue light emitting graphene oxide nanosheets fabricated by surface functionalization

Graphene and graphene oxide (GO) attract increasing attention due to their unique physical and chemical properties and thus the potential applications in optics and electronics. However, the gapless band structure greatly limits their wide applications in opto-electronic devices. Surface functionalization was found to be an effective method to tune the properties of graphene and GO. In the present report, GO hybrid materials with blue-emission were fabricated through the GO surface functionalization with aryl diazonium salts of 2-aminoanthracene. The obtained hybrids were carefully characterized with atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and UV-Vis absorption spectroscopy. Significantly different from the cyan emission (∼491 nm) of monomeric 2-aminoanthracene, the as-synthesized GO hybrid composites exhibited strong blue photoluminescence centered at ca. 400 nm. The large blue shift of the luminescence (∼91 nm) obtained from the functionalized GO could be partly ascribed to the rigid chemical environment with anthryl moieties chemically bonded onto GO surface. Such surface-functionalized GO hybrids with unique optical properties render them exciting materials for opto-electronic devices.