A β-cyclodextrin/graphene oxide hybrid gel with smart responsiveness

Journal of Inclusion Phenomena and Macrocyclic Chemistry - Even through gels based on the polymer modified with β-cyclodextrin have been researched widely, there are only few studies focus on...     

Quiescent hydrothermal synthesis of reduced graphene oxide–periodic mesoporous silica sandwich nanocomposites with perpendicular mesochannel alignments

Quiescent hydrothermal conditions were applied to synthesis of the sandwich nanocomposites of reduced graphite oxide (rGO) and periodic mesoporous silica (PMS) with vertically aligned mesochannels. It was found that the formation of the PMS–rGO–PMS sandwich structure is very sensitive to the surface and synthesis conditions. Although a higher temperature hydrothermal condition promotes reduction of GO and formation of bulky mesoporous nanoparticles, quiescent hydrothermal condition can serve as an alternative approach to obtain the unusual nanocomposites and slightly promote the structural stability of PMS on the surface of rGO.     

UV-assisted synthesis of reduced graphene oxide–ZnO nanorod composites immobilized on Zn foil with enhanced photocatalytic performance

Research on Chemical Intermediates - ZnO nanorods were hydrothermally grown on Zn foil in an alkaline solution and the immobilized nanorods were subsequently hybridized with reduced graphene oxide...     

Synthesis and properties of novel aliphatic polycarbonate from carbon dioxide with 1,2-butylene oxide and ε-caprolactone

A new degradable aliphatic poly(butylene-co-e-caprolactone carbonate) (PBCL) was synthesized through the terpolymerization of carbon dioxide, 1,2-butylene oxide (BO) and e-caprolactone (CL), a polymer supported bimetallic complex (PBM) was used as a catalyst. The terpolymers prepared were characterized by FT-IR,1H NMR, 13C NMR, WXRD and DSC. The hydrolysis tests were carried out to appraise the degradability of the copolymers.     

Mechanical and sodium ion conductivity properties of graphene oxide–incorporated nanocomposite polymer electrolyte membranes

Journal of Solid State Electrochemistry - Graphene oxide (GO) nano-sheets incorporated PEO/PVA composite membranes complexed with NaIO4 salt at different concentrations were prepared using the...     

A novel oxygen-dependent deoximation by nitric oxide

A variety of aldoximes and ketoximes were oxidized to corresponding aldehydes and ketones by nitric oxide in the presence of oxygen.A presumed mechanism was suggested.     

Electrochemical determination of picric acid based on platinum nanoparticles–reduced graphene oxide composite

Platinum nanoparticles–reduced graphene oxide composite-modified glassy carbon electrode (PtNPs–rGO/GCE) was developed as a simple, selective and sensitive electrochemical sensor for determination of picric acid (PA). Cyclic voltammogram (CV) of PA showed three well-defined irreversible reduction peaks at the potentials of ?0.43, ?0.57 and ?0.66 V versus Ag/AgCl. In this work, the interference effect of other nitrophenol compounds (NPhCs) was significantly reduced by appropriate adjusting of pH. Square wave voltammetry was used for quantification of PA in the range of 5–500 µM (1.15–115 mg L^?1) with practical detection limit of 1 µM (0.23 mg L^?1). The proposed sensor was successfully applied for the determination of PA in two natural water samples.     

Comparison of performances of bioanodes modified with graphene oxide and graphene–platinum hybrid nanoparticles

The performances of graphene oxide (GO) and graphene–platinum hybrid nanoparticles (Gr-Pt hybrid NPs) were compared for biofuel cell (BFC) systems. This is the first study that constitutes these nanomaterials in BFC systems. For this purpose, fabricated bioanodes were combined with laccase modified biocathode in a single cell membraneless BFC. Power and current densities of these systems were calculated as 2.40 μW cm^− 2 and 211.90 μA cm^− 2 for GO based BFC and 4.88 μW cm^− 2 and 246.82 μA cm^− 2, for Gr-Pt hybrid NPs based BFC. As a result, a pioneer study which demonstrates the effective performances of combination of graphene with Pt was conducted.     

Non-aqueous approach to the preparation of reduced graphene oxide/α-Ni(OH)2 hybrid composites and their high capacitance behavior

Reduced graphene oxide/α-Ni(OH)(2) composites present high electrochemical properties, with specific capacitance of 1215 F g(-1) at 5 mV s(-1) scan rate, since graphene as conductive matrix provides electronic conduction pathway.     

One-pot synthesis of graphene–cuprous oxide composite with enhanced photocatalytic activity

In this paper, graphene–cuprous oxide (G–Cu₂O) composites were synthesized at room temperature using graphene oxide (GO) as two-dimensional support. From Zeta potential analysis, the surface charge of G–Cu₂O composites altered from positive to negative, which favors the adsorption and photodegradation of positively charged dyes. Compared with Cu₂O under similar synthesis condition, the G–Cu₂O composites demonstrated improved photodegradation activity for methylene blue (MB) dye under visible light. Controlled experiments indicated that the G–Cu₂O composite synthesized with 80 mg GO in the reaction system possessed more negative Zeta potential, highest specific surface area and thus presented the highest photocatalytic activity. Electrons mechanism for the improved photocatalytic performance of G–Cu₂O composite was proposed in the degradation of MB.     

A novel nanocomposite matrix based on graphene oxide and ferrocene-branched organically modified sol–gel/chitosan for biosensor application

A novel platform for the fabrication of a glucose biosensor was successfully constructed by entrapping glucose oxidase (GOD) in a ferrocene (Fc)-branched organically modified silica material (ormosil)/chitosan (CS)/graphene oxide (GO) nanocomposite. The morphology, structure, and electrochemistry of the nanocomposite were characterized by transmission electron microscopy, X-ray powder diffraction, UV–vis spectroscopy, Fourier transform infrared spectroscopy, and electrochemical techniques. Results demonstrated that the proposed electrochemical platform not only provided an excellent microenvironment to maintain the bioactivity of the immobilized enzyme, but also effectively prevented the leakage of both the enzyme and mediator from the matrix and retained the electrochemical activity of Fc. Furthermore, dispersing GO within the Fc-branched ormosil/CS matrix could significantly improve the stability of GO and make it exhibit a positive charge, which was more favorable for the further immobilization of biomolecules, such as GOD, with higher loading. Moreover, it could also improve the conductivity of the matrix film and facilitate the electron shuttle between the mediator and electrode. Under optimal conditions, the designed biosensor to glucose exhibited a wide and useful linear range of 0.02 to 5.39 mM with a low detection limit of 6.5 μM. The value of K _M ^app was 4.21 mM, indicating that the biosensor possesses higher biological affinity to glucose. The present approach could be used efficiently for the linkage of other redox mediators and immobilize other biomolecules in the process of fabricating novel biosensors.     

Improved lithium cyclability and storage in mesoporous SnO2 electronically wired with very low concentrations (≤1 %) of reduced graphene oxide

On the wire: Mesoporous tin dioxide (SnO(2)) wired with very low amounts (≤1?%) of reduced graphene oxide (rGO) exhibits a remarkable improvement in lithium-ion battery performance over bare mesoporous or solid nanoparticles of SnO(2). Reversible lithium intercalation into SnO(2)/SnO over several cycles was demonstrated in addition to conventional reversible lithium storage by an alloying reaction.     

Synthesis of a novel tri-antennary galactoside with high hepatocyte targeting

A novel bifunctional compound carrying cluster thiogalactoside as the cell targeting ligands was synthesized for gene delivery to hepatocytes. Tetra-antennary dendr-OMs4 5 was used as a scaffold for the attachment of three galactosides, while the other mesylate end was linked with cholesterol through poly(ethylene glycol) chain. This design provided an effective entry for the synthesis of the bifunctional compound.     

Construction of hierarchical porous graphene–carbon nanotubes hybrid with high surface area for high performance supercapacitor applications

Journal of Solid State Electrochemistry - Unlike activated carbon, graphene sheets are lack of ion pathways on their basal planes and prone to agglomerate or restack unfortunately for their strong...     

A novel hierarchical nanobiocomposite of graphene oxide–magnetic chitosan grafted with mercapto as a solid phase extraction sorbent for the determination of mercury ions in environmental water samples

New mercapto-grafted graphene oxide–magnetic chitosan (GO–MC) has been developed as a novel biosorbent for the preconcentration and extraction of mercury ion from water samples. A facile and ecofriendly synthesis procedure was also developed for modification of GO–MC with 3-mercaptopropyltrimethoxysilane. The prepared nanocomposite material (mercapto/GO–MC) was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDX). The mercury analysis was performed by continuous-flow cold vapor atomic absorption spectrometry. The parameters affecting the extraction and preconcentration processes were carried out. The optimum conditions were found to be 60 mg of sorbent, pH of 6.5, 10 min for adsorption time, 3 mL of HCl (0.1 mol L⁻¹)/thiourea (2% w/v) as the eluent and 250 mL for breakthrough volume. An excellent linearity was achieved in the range of 0.12–80 ng mL⁻¹ (R² = 0.999) at a preconcentration factor of 80. The limit of detection and quantification were achieved as 0.06 ng mL⁻¹ and 0.12 ng mL⁻¹, respectively. A good repeatability was obtained with the relative standard deviation (RSD) of 4.7%. Furthermore, real water samples were analyzed and good recoveries were obtained from 95 to 100%.     

The electrochemical activities of anthraquinone monosulfonate adsorbed on the basal plane of reduced graphene oxide by π–π stacking interaction

The electrochemical properties of anthraquinone monosulfonate (AQS) adsorbed on the basal plane of chemically-reduced graphene oxide (RGO) by π–π stacking interaction were investigated. The AQS/RGO nanocomposites were synthesized via a simple reduction–adsorption method and characterized with various techniques, and the surface concentration of AQS on the basal plane of RGO was estimated to be 1.72?×?10^?12 mol cm^?2. Electrochemical tests showed that the AQS/RGO nanocomposites accelerated the heterogeneous electron transfer, when ferro/ferricyanide was used as a redox probe, and RGO facilitated the electron transfer between AQS and the surface of glassy carbon electrode, producing a well-defined redox couple centered at ?0.490 V versus SCE at neutral medium. Compared with AQS and RGO modified glassy carbon (GC) electrode, the AQS/RGO nanocomposites showed better electrocatalytic activity towards oxygen reduction reaction. Rotating disk electrode data showed that the reduction of O₂ on AQS/RGO/GC electrode underwent a two-electron process to H₂O₂ at low overpotential and shifted to four-electron reduction to H₂O at relatively high overpotential. The present work demonstrates that AQS can be an efficient catalyst when noncovalently functionalized on the basal plane of RGO for electrochemical applications.     

Prussian blue–gold nanoparticles-ionic liquid functionalized reduced graphene oxide nanocomposite as label for ultrasensitive electrochemical immunoassay of alpha-fetoprotein

In this work, poly(diallyldimethylammonium chloride) (PDDA) protected Prussian blue/gold nanoparticles/ionic liquid functionalized reduced graphene oxide (IL-rGO-Au-PDDA-PB) nanocomposite was fabricated. The resulting nanocomposite exhibited high biocompatibility, conductivity and catalytic activity. To assess the performance of the nanocomposite, a sensitive sandwich-type immunosensor was constructed for detecting alpha-fetoprotein (AFP). Greatly enhanced sensitivity for this immunosensor was based on triple signal amplification strategies. Firstly, IL-rGO modified electrode was used as biosensor platform to capture a large amount of antibody due to its increased surface area, thus amplifying the detection response. Secondly, a large number of Au-PDDA-PB was conjugated on the surface of IL-rGO, which meant the enrichment of the signal and the more immobilization of label antibody. Finally, the catalytic reaction between H₂O₂ and the IL-rGO-Au-PDDA-PB nanocomposite further enhanced the signal response. The signals increased linearly with AFP concentrations in the range of 0.01–100 ng mL⁻¹. The detection limit for AFP was 4.6 pg mL⁻¹. The immunosensor showed high sensitivity, excellent selectivity and good stability. Moreover, the immunosensor was applied to the analysis of AFP in serum sample with satisfactory result.     

High-performance (NH4)2V6O16·0.9H2O nanobelts modified with reduced graphene oxide for aqueous zinc ion batteries

Ammonium vanadate has been considered as a competitive high-performance cathode material for aqueous Zn-ion batteries. However, it still suffers from insufficient rate capability and poor cyclability due to the low electronic conductivity. Herein, (NH₄)₂V₆O₁₆·0.9H₂O nanobelts with reduced graphene oxide (RGO) modification are synthesized by one-step hydrothermal reaction. Benefiting from the addition of RGO, an excellent electrochemical performance of (NH₄)₂V₆O₁₆·0.9H₂O@RGO nanobelts can be obtained. The (NH₄)₂V₆O₁₆·0.9H₂O@RGO displays a high-rate capacity and a high energy density of 386 Wh/kg at 72 W/kg. In particular, after 1000 cycles at 5 A/g, the capacity remains at 322 mAh/g with 92.8% capacity retention. In addition, the key reaction mechanisms of reversible Zn²⁺insertion/extraction in (NH₄)₂V₆O₁₆·0.9H₂O@RGO are clarified.