GO Hybrid Research Articles

Synthesis of Nanoalumina/Graphene Oxide Hybrid for Improvement Tribological Property of Aluminum

In this research, an efficient, facile and low-cost chemical method was the developed for preparation of Al2O3/graphene oxide (GO) hybrid nanoparticle (Al2O3Nps/GO), through in situ synthesis of Al2O3Nps in the presence of GO. Al2O3Nps/GO hybrid nanoparticles added to aluminum powder and nanocomposites were fabricated by powder metallurgy processing and consolidated via the spark plasma sintering. Structure, morphology and composition of the hybrid particle were investigated by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectra and thermogravimetric analysis. The results confirmed successful incorporation of alumina over GO surface and formation of pure and homogenized γ-Al2O3Nps/GO hybrid particle. Physical and tribological properties of hybrid nanocomposite were investigated by using density, hardness and wear analyses. High relative density was obtained for Al 1 wt% γ-Al2O3Nps/GO. Tribological property was studied by pin-on-disk tribometer and showed that the friction coefficient significantly decreased with increasing γ-Al2O3Nps/GO content.

Enhanced fluoride uptake by bimetallic hydroxides anchored in cotton cellulose/graphene oxide composites.

A novel hybrid nanomaterial was synthesized by embedding the bimetallic Zr and La (hydro)xides onto the cotton cellulose/graphene oxide composites (CC/GO composites), forming the Zr-La-CC/GO nanocomposites. Selective uptake of fluoride onto the Zr-La /GO hybrids in multiple competitive environments were evaluated. Morphological characteristics of Zr-La-CC/GO nanocomposites reflected the well distributions of embedded Zr and La hydroxides in the nanocomposites. Results also indicated that the encapsulated bimetallic hydroxides in Zr-La-CC/GO hybrids exhibited extremely high fluoride adsorption capacity and stability. XPS investigation exhibited the strong ZrF and LaF bonds in spent Zr-La-CC/GO nanocomposites, and the bonds were weakened at higher pH, which was consistent with the adsorption results. In addition, CC/GO composites using as the host could also exert the strong shielding effect to improve the stability of embedded La and Zr species so as only a low La dissolution (<4.2%) and almost no Zr leaching (0.1%) were observed in high HA concentration. What's more, the Zr-La-CC/GO nanocomposites have also shown great potential application for defluoridation in field.

Cationic Porphyrin-Graphene Oxide Hybrid: Donor-Acceptor Composite for Efficient Photoinduced Electron Transfer.

Non-covalent nanohybrids composed of cationic 5,10,15,20-tetra(4-trimethylammoniophenyl)porphyrin tetra(p-toluenesulfonate) (TMAP) and the graphene oxide sheets were prepared under two pH values (6.2 vs. 1.8). The TMAP molecule was positively charged, regardless of the pH value during preparation. However, protonation of the imino nitrogens increased the overall charge of the porphyrin molecule from +4 to +6 (TMAP4+ and TMAP6+ ). It was found that at acidic pH, interaction of TMAP6+ with GO was largely suppressed. On the other hand, results of FTIR, Raman spectroscopy, thermogravimetric analysis, atomic force microscopy (AFM) and elemental analysis confirmed effective non-covalent functionalization of graphene oxide with cationic porphyrin at pH 6.2. The TMAP4+ -GO hybrids exhibited well defined structure with a monolayer of TMAP4+ on the GO sheets as confirmed by AFM. Formation of the ground-state TMAP4+ -GO complex in solution was monitored by the red-shift of the porphyrin Soret absorption band. This ground-state interaction between TMAP4+ and GO is responsible for the static quenching of the porphyrin emission. Fluorescence was not detected for the nanohybrid which indicated that a very fast deactivation process had to take place. Ultrafast time-resolved transient absorption spectroscopy clearly demonstrated the occurrence of electron transfer from the photoexcited TMAP4+ singlet state to GO sheets, as proven by the formation of a porphyrin radical cation.

Energy-efficient sonochemical approach for the preparation of nanohybrid composites from graphene oxide and metal-organic framework

Two-fold interpenetration zinc-based metal-organic framework/graphene oxide (TMU-16-NH2/GO) nanohybrid materials were synthesized under a green, simple and large-scale sonochemical preparation method at room temperature and atmospheric pressure. The role of concentrations of graphene oxide on size and morphology of nanostructures TMU-16-NH2/GO hybrid have been studied. The materials were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy and nitrogen adsorption. Both of the pure MOF and the nanohybrid MOF/GO composites exhibit microporous structure with a small number of mesopores. TMU-16-NH2 shows type IV isotherm with a H4 hysteresis loop, while the isotherm of TMU-16-NH2/GO appears to show normal Type II adsorption with a Type H3 hysteresis loop. The results obtained demonstrate this method to be applicable to the synthesis of other MOFs/GO nanohybrids and may possibly find various forthcoming industrial and technological applications.

Synergic effect of plasmonic gold nanoparticles and graphene oxide on the performance of glucose sensing

A highly sensitive Au–GO hybrid nanostructure based non-enzymatic glucose biosensor is fabricated and exhibits superior sensitivity of 84.53 μA mM−1 cm−2. The biosensor also has applications for the detection of glucose in human blood serum, food samples and drinks.

Structure and Properties of Sulfonated Poly(ether ether ketone) Hybrid Membrane with Polyaniline‐Chains‐Modified Graphene Oxide and Its Application for Vanadium Redox Flow Battery

AbstractA series of acid‐base hybrid membranes (SPEEK/PANi‐GO), composed of sulfonated poly(ether ether ketone) (SPEEK) and polyaniline‐functionalized graphene oxide (PANi‐GO), have been prepared and applied for vanadium redox flow battery (VRB). The chemical composition and structure for PANi‐GO nanosheets and SPEEK/PANi‐GO hybrid membranes are in detail characterized. Physicochemical properties such as ion exchange capacity, proton conductivity and vanadium ion permeability are highly based on the loadings of PANi‐GO nanofillers. The formed acid‐base pairs, originated from ‐SO3H of SPEEK and ‐NH group of PANi‐GO, decrease the swelling ratio and vanadium ion permeability. Ion selectivity shows a strong dependence upon the PANi‐GO content, and it presents a maximum value at 2% loading. VRB performance by SPEEK/PANi‐GO‐2 hybrid membrane exhibits a higher coulombic efficiency (CE: 98.5%) and energy efficiency (EE: 81.7%) at 30 mA cm−2, as compared with Nafion 117 (CE: 88.9% and EE: 72.5%) and SPEEK membrane (CE: 89.8% and EE: 69%). The self‐discharge time with SPEEK/PANi‐GO‐2 (58 h) is longer than that of Nafion 117 membrane (26 h), and a good chemical and oxidation stability is well demonstrated after 300 times charge‐discharge cycles for SPEEK/PANi‐GO‐2 hybrid membrane. These SPEEK/PANi‐GO hybrid membranes demonstrate a promising application for VRB system.

Facile Synthesis of PtCu Alloy/Graphene Oxide Hybrids as Improved Electrocatalysts for Alkaline Fuel Cells.

Morphology-controllable preparation of Pt-based nanoalloys supporting on carbonaceous materials is a potential strategy to enhance the catalytic properties for oxygen reduction reaction (ORR) and ethanol oxidation reaction (EOR); they are recognized as irreplaceable electrode reactions in proton-exchange membrane ethanol fuel cells. Herein, we exhibit a facile, one-step synthesis method to directly prepare composition-tunable PtCu alloy/graphene oxide (GO) hybrids. The structure of the as-synthesized PtCu alloy/GO hybrids has been analyzed using transmission electron microscopy, high resolution transmission electron microscopy, energy-dispersive X-ray, X-ray diffraction, inductively coupled plasma, and X-ray photoelectron spectroscopy. In the PtCu alloy/GO hybrids, the PtCu alloy nanoparticles well disperse on GO, and the size is below 5.0 nm. The catalysis for ORR and EOR of the as-synthesized PtCu/GO hybrids has been evaluated in alkaline solution. Compared to commercial Pt/C, the PtCu/GO hybrids exhibit much higher mass activity and stability. The mass activities toward ORR/EOR on Pt75.4Cu24.6/GO hybrids are 5.3/2.36 times higher than the commercial Pt/C. This study proves that the as-synthesized PtCu/GO hybrids can be used as improved catalysts for ORR and EOR in alkaline medium.

Reduced graphene oxide decorated with carbon nanopolyhedrons as an efficient and lightweight microwave absorber

Graphene-based composites are becoming a new kind of microwave absorbers that can overcome the challenges related to the performance and light weight in electromagnetic pollution precaution. Herein, a series of reduced graphene oxide decorated with carbon nanopolyhedrons (CNPs/rGO) composites have been successfully fabricated through in situ pyrolysis of ZIF-8/GO hybrids. It is found that GO can restrain the growth of ZIF-8 crystals and produce small-size CNPs after high-temperature pyrolysis, and CNPs will suppress the re-stacking of rGO nanosheets. More importantly, the coupling of CNPs and rGO not only generates the desirable synergistic effects, but also accounts for the profitable interfacial polarization. Therefore, the electromagnetic parameters and microwave absorption properties of these composites can be rationally modulated in terms of the amount of GO. The optimized CNPs/rGO composite exhibits strong reflection loss [−66.2 dB (6.2 GHz, 2.89 mm)] and broad qualified bandwidth (over −10 dB in 3.2–18.0 GHz with integrated absorber thickness of 1.0–5.0 mm), which are superior to many graphene-based composites with high-density magnetic components. Electromagnetic analysis reveals that good attenuation ability and impedance matching are responsible for its excellent performance. It is believed that these results may inspire the design of lightweight microwave absorbers in the future.

Solid phase microextraction of phthalic acid esters from vegetable oils using iron (III)-based metal-organic framework/graphene oxide coating

A hybrid composite featuring an iron-based metal-organic framework Material of Institute Lavoisier-88(Fe) and graphene oxide (MIL-88(Fe)/GO) was synthesized and used as the solid-phase microextraction (SPME) coating. The SPME fiber was prepared by covalent bonding of the MIL-88(Fe)/GO composite onto the stainless steel substrate. The fiber had a good durability and allowed >100 replicate extractions. The developed method, which combined the MIL-88(Fe)/GO coated fiber based SPME with gas chromatography-flame ionization detection (GC-FID), achieved low limits of detection (0.5–2.0 ng g−1, S/N = 3) and good linearity (r2 > 0.994) for the phthalic acid esters (PAEs) from various vegetable oil samples. The repeatability and fiber-to-fiber reproducibility were in the range of 4.0–9.1% and 5.7–11.4%, respectively. The method was successfully applied to the analysis of PAEs from vegetable oil samples with good recoveries (83.1–104.1%) and satisfactory precisions (RSDs < 10.5%), indicating that the MIL-88(Fe)/GO hybrid composite is a good coating material for the SPME of PAEs.

PtNi Alloy Cocatalyst Modification of Eosin Y-Sensitized g-C3N4/GO Hybrid for Efficient Visible-Light Photocatalytic Hydrogen Evolution

An economic and effective Pt-based alloy cocatalyst has attracted considerable attention due to their excellent catalytic activity and reducing Pt usage. In this study, PtNi alloy cocatalyst was successfully decorated on the g-C3N4/GO hybrid photocatalyst via a facile chemical reduction method. The Eosin Y-sensitized g-C3N4/PtNi/GO-0.5% composite photocatalyst yields about 1.54 and 1178 times higher hydrogen evolution rate than the Eosin Y-sensitized g-C3N4/Pt/GO-0.5% and g-C3N4/Ni/GO-0.5% samples, respectively. Mechanism of enhanced performance for the g-C3N4/PtNi/GO composite was also investigated by different characterization, such as photoluminescence, transient photocurrent response, and TEM. These results indicated that enhanced charge separation efficiency and more reactive sites are responsible for the improved hydrogen evolution performance due to the positive synergetic effect between Pt and Ni. This study suggests that PtNi alloy can be used as an economic and effective cocatalyst for hydrogen evolution reaction.Graphical abstractA significant enhancement of photocatalytic H2 evolution is realized over the Eosin Y-sensitized g-C3N4/PtNi/GO composite with PtNi alloy as an efficient cocatalyst.

Ethanol–water ambient precipitation of {111} facets exposed Ag3PO4 tetrahedra and its hybrid with graphene oxide for outstanding photoactivity and stability

The work presents the combinative merits of {111} facet effect and the GO hybrid of Ag3PO4 photocatalyst with dramatically improved photocatalytic activity and admirable circulation runs for water treatment.

Pressure-assisted synthesis of a polyaniline–graphite oxide (PANI–GO) hybrid and its friction reducing behavior in liquid paraffin (LP)

PANI–GO hybrids were preparedviaa pressure-assisted method, which can significantly enhance the anti-friction property of base oil at the optimum concentration of 0.012 wt%.

Synergistically Enhanced Optical Limiting Property of Graphene Oxide Hybrid Materials Functionalized with Pt Complexes.

Recently, graphene-based materials have become well-known nonlinear optical materials for the potential application of laser protection. Two new graphene oxide-platinum complex (GO-Pt) hybrid materials (GO-Pt-1, GO-Pt-2) have been fabricated through covalent modification and electrostatic adsorption of different Pt complexes with GO. The structural and photophysical properties of the resultant hybrid materials were studied. The nonlinear optical properties and optical power limiting (OPL) performance of Pt complexes, GO, and GO-Pt hybrid materials were investigated by using Z-scan measurements at 532 nm. At the same transmittance, the results illustrate that functionalization of GO makes GO-Pt hybrid materials possess better nonlinear optical properties and OPL performance than individual Pt complexes and GO due to a combination of nonlinear scattering, nonlinear absorption, and photoinduced electron and energy transfer between GO and Pt complex moieties. Furthermore, the nonlinear optics and OPL performance of GO-Pt-2 are better than those of GO-Pt-1, due to not only the excellent optical limiting of Pt-2 and more molecules per area of GO but also the way of combination of Pt-2 and GO.

Continuous Production of Hollow Hydrogel Fibers with Graphene Inner Wall

Hydrogel fiber with spatiotemporal properties such as great aspect ratio, large surface area/volume ratio, orientation and knittability, has been considered as the potential application materials in the field of biomedicine area. On the basis of dynamic-crosslinking-spinning we reported before, a novel GO/PEG-PEGDA core-sheath hydrogel fiber was fabricated continuously. Moreover, uniform rGO-PEGDA hollow fiber was obtain after reduction process. The diameter of core and sheath can be controlled separately by adjusting extrusion rate of core solution and sheath solution, respectively. This novel series GO hybrid hydrogel fibers with core-shell or hollow structure have potential application on nerve and muscle tissue engineering.

SiO2 particle-supported ultrathin graphene hybrids/polyvinylidene fluoride composites with excellent dielectric performance and energy storage density

Polymer composites of polyvinylidene fluoride (PVDF) filled with SiO2–reduced graphene oxide (RGO) hybrids were fabricated and their dielectric properties and energy storage performance were systematically investigated. Hybrid SiO2–RGO with core-cell were prepared by using of SiO2 particles as rigid template and the thermal reduction of the electrostatic assembled SiO2–GO hybrids, in which the inside rigid particles could support the uniform dispersion of ultrathin RGO sheets in the PVDF matrix and thus leading to a much lower percolation threshold (0.141 vol% for RGO in composite) than those of most reported graphene/polymer composites. Only a small amount of RGO in composites lead to high dielectric permittivity (72.94) and low dielectric loss (0.059) which should be ascribed to the increase of interfacial polarization between filler and matrix. More importantly, the composites with high breakdown strength (2438 kV/cm), energy density (0.301 J/cm3) and charge–discharge efficiency (91.2%) can be achieved by incorporation of 10 wt% filler loading. This study provides a special pathway to ensure the dispersion and highly efficient usage of ultrathin graphene sheets in the polymer matrix and achieve graphene/polymer composite with excellent dielectric performance and energy storage density.

A novel ternary CuO decorated Ag3AsO4/GO hybrid as a Z-scheme photocatalyst for enhanced degradation of phenol under visible light

A novel Z-scheme ternary CuO/Ag3AsO4/GO hybrid having significant visible light catalytic activity and stability is successfully synthesized via a self-assembly method.

Self-rectifying bipolar resistive switching memory based on an iron oxide and graphene oxide hybrid.

A resistive random access memory (RRAM) device with self-rectifying I-V characteristics was fabricated by inserting a silicon nitride (Si3N4) layer between the bottom electrode and solution-processed active material of an iron oxide-graphene oxide (FeOx-GO) hybrid. The fabricated Au/Ni/FeOx-GO/Si3N4/n+-Si memory device exhibited an excellent resistive switching ratio and a rectification ratio higher than 104. In the Au/Ni/FeOx-GO/Si3N4/n+-Si device, resistive switching occurs in both the FeOx-GO and Si3N4 layers separately, resulting in a highly uniform and stable switching performance. The resistive switching from a high resistance state to a low resistance state in the Au/Ni/FeOx-GO/Si3N4/n+-Si device occurs through a trap-assisted tunneling process in the Si3N4 layer, enabled by the FeOx-GO layer which prevents diffusion of the migrating Ni metal into the switching nitride layer. The intrinsic self-rectifying characteristics of our memory devices arise from the asymmetric barriers for electrons tunneling into the traps of the Si3N4 layer which is sandwiched between the top and bottom electrodes having dissimilar work functions. Our study confirmed that integrating a suitable dielectric layer into the conventional RRAM cell is an innovative strategy to simplify the architecture and fabrication process to realize self-rectifying crossbar arrays.

The effects of central metals on ammonia sensing of metallophthalocyanines covalently bonded to graphene oxide hybrids

Stably dispersed aPcM–GO hybrids were prepared by a facile amidation reaction with excellent NH3 sensing properties at room temperature, which rely to the aPcM functionalization on GO.

Bioinspired hybrid material composed of helical polymer grafts and graphene oxide: Reversible transformation of particulate and extended structures of the grafts and application in chiral enrichment

Abstract Inspired by jellyfish, this article reports a novel type of GO-derived reversible transition hybrid material, in which optically active helical substituted polyacetylene was covalently grafted on GO sheets. The polymer chains underwent a reversible transition between forming particles and dispersing state upon changing the solvent. Transmission electron microscopy (TEM) confirmed the reversible transition process. Circular dichroism and UV–vis absorption spectroscopies demonstrated the fascinating optical activity of the GO hybrids, which originated in the helical polymer chains adopting predominantly one helicity. The enantio-differentiating enrichment experiments demonstrated the potential applications of the novel hybrids as reusable chiral materials during the reversible transition process, in which l -dopamine and l -phenylalanine were preferentially adsorbed when the polymer chains formed particles.

Graphene oxide decorated with Fe3O4 nanoparticles with advanced anticorrosive properties of epoxy coatings

Fe3O4 nanoparticles-decorated graphene oxide (Fe3O4–GO) hybrid were synthesized with the help of silane coupling agents and the appropriate proportion was examined. Then, the epoxy coatings were fabricated by incorporation of GO sheets, Fe3O4 nanoparticles, and Fe3O4–GO hybrid into epoxy resin with same concentrations. Comparison with other nanofillers demonstrated that Fe3O4–GO hybrid achieved a homogeneous dispersion within epoxy resin, as well as significantly enhanced anticorrosive properties of epoxy coatings, owing to their excellent dispersion, sheet-like structure and inherent blocking micro-pores property. More strikingly, the sheet-like structure of hybrid was a promising candidate for preparation of anticorrosive coatings.