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Abstract: We report a facile solvothermal synthesis of reduced graphene oxide/Zn0.8Cd0.2S (GZCS) hybrid nanomaterial as a photocatalyst, in which Zn0.8Cd0.2S nanoparticles were homogeneously distributed on the surface of reduced graphene oxide (RGO), showing a good visible light response. The photocatalytic activities for as-prepared GZCS were evaluated by the degradation of methylene blue (MB) in aqueous solution under visible light irradiation. The results showed that the GZCS had higher photocatalytic activity than pure Zn0.8Cd0.2S. The GZCS with 5wt% RGO content exhibited the highest photodegradation efficiency of MB (96%), which was 2.7 times of pure Zn0.8Cd0.2S. And it also showed high photocatalytic stability. [Copyright &y& Elsevier]

Hydrophilic hemostatic sponge plays an important role in trauma bleeding control because of its robust coagulant functions. However, its strong tissue adhesion can easily result in wound tear and rebleeding during removing the sponge. Herein, the design of a hydrophilic anti-adhesive chitosan/graphene oxide composite sponge (CSAG) that possesses stable mechanical strength, rapid liquid absorption and strong intrinsic/extrinsic coagulation stimulations, is reported. For one thing, CSAG exhibits outstanding hemostatic performance, which significantly outperforms two commercial hemostats in two in vivo serious bleeding models. For another, CSAG shows low tissue adhesion; its peeling force is approximately 79.3 % lower than the commercial gauze. Moreover, in the peeling process, CSAG triggers partial detachment of the blood scab, because of the exist of bubbles or cavities at the interface, allowing the CSAG to be easily and safely peeled off from the wound without rebleeding. This study opens new avenues in constructing anti-adhesive trauma hemostatic materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract The interaction between active materials and conductive additives is complicated but crucial within electrochemical energy storage devices. Here, we first identify that CH 2 groups drive the compositing process, leading to an effective formation of Co-O-C chemical bonding serving as the bridge between reduced graphene oxide(rGO) and hydroxide. Due to the enhanced electron transport, a dramatically improved specific capacity is achieved as high as 1368 F/g for rGO/Co(OH) 2 electrode at a current density of 0.5 A/g. Thus, we provide new insights into graphene/hydroxide compositing mechanism, which has a significant impact on enhancing electron transport for a variety of graphene/hydroxide in energy storage systems. Highlights • CH 2 groups transform into Co-O-C bonds as the bridge between graphene and Co(OH) 2. • rGO/Co(OH) 2 exhibits a highly crystalline feature. • BG/Co(OH) 2 holds more Co3+ ions and Co-O tetrahedral structures. • C-(O-Co) n affords abundant electron transport channels. • A dramatically high specific capacity of 1368 F/g is achieved for rGO/Co(OH) 2. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

In this article, a green and controllable method was introduced to reduce graphene oxide (GO) via a hydrothermal deoxygenation process. The reduced graphene oxide (RGO) obtained was characterized by atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-Vis absorption spectroscopy, et al. The reduction degree as well as residual chemical components can be adjusted by changing the reaction time and pH conditions. Both GO and RGO were applied as SERS substrates, and their SERS activities were studied and compared. The mechanism on SERS enhancement of GO and RGOs was discussed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A delicate configuration of dual‐ion battery is proposed to achieve optimum energy/power density. High potential intercalation reaction of positive electrode contributes to high energy density and quick absorption/desorption of negative is beneficial for power density. Such novel designed electrochemical energy storage device enables access to optimum power/energy density. [ABSTRACT FROM AUTHOR]

Effective hemostasis for noncompressible bleeding has been a key challenge because of the deep, narrow, and irregular wounds. Swellable gelatin is an available hemostatic material but is limited by weak mechanical strength and slow liquid absorption. Herein, the design of a gelatin and graphene oxide (GO) composite sponge (GP-GO) that possesses stable cross-linked networks and excellent absorbability, is reported. The GP-GOs are constructed via the thermal radical polymerization technique, using methacrylate gelatin (Gel-MA) and poly(ethylene glycol) diacrylate (PEGDA) as the crosslinker, while GO is uniformly fixed in the network via the curing reaction to further strengthen the stability. The optimized GP-GO 5 with GO addition (5 wt%) exhibits high porosity (> 90%), distinguished liquid absorption rate (106 ms), rapidly responsive swelling (422% expansion within 10 s), and stable mechanical properties. The addition of GO effectively reinforces coagulation stimulation of GP-GOs though the stimulation of platelets and the enrichment effect at the interface, significantly reducing the blood coagulation index (BCI) (< 17.5%). Hemostatic mechanism study indicated the liquid absorbability of GP-GOs is the critical foundation to trigger the subsequent physical expansion, blood cells enrichment, and coagulation stimulations. Besides, GP-GO 5 exhibits excellent biosafety assessed by hemolysis and cytotoxicity. Under the synergistic effects, the biocompatible GP-GO 5 showed excellent hemostatic properties in the hemostasis of severe bleeding and noncompressible wounds compared with a pure gelatin sponge (GP) and the commercial hemostatic agent Celox™. This study demonstrated a promising candidate for practical application of noncompressible wound hemostasis. [Display omitted] • A series of GP-GOs with stable covalently cross-linked networks are prepared. • GO efficiently reinforces liquid absorption and coagulation stimulation of GP-GO. • Absorbability of GP-GO is critical for its multi-mechanism synergistic hemostasis. • Hemostasis of GP-GO for noncompressible wound significantly outperforms the hemostat. [ABSTRACT FROM AUTHOR]

Abstract: The binding of DNA with graphene oxide (GO) is important for applications in disease diagnosis, genetic screening, and drug discovery. The standard assay methods are mainly limited to indirect observation via fluorescence labeling. Here we report the use of surface plasmon resonance for direct sensing of DNA/GO binding. We show that this can be used for ultra-sensitive detection of single-stranded DNA (ssDNA). Furthermore, the results provide a more direct probe of DNA/GO binding abilities and confirm that hydrogen bonding plays a key role in the interaction between GO and ssDNA. This enables to a novel biosensor for highly sensitive and selective detection of ssDNA based on indirect competitive inhibition assay (ICIA). We report development of such a sensor with a linear dynamic range of 10−14–10−6 M, a detection limit of 10fM and a high level of stability during repeated regeneration. [Copyright &y& Elsevier]

We report on a new and facile method for the preparation of well-dispersed gold-palladium (AuPd) flower-shaped nanostructures on sheets of graphene oxide (GO). Transmission electron microscopy and high angle annular dark field STEM were used to characterize the morphology and composition of the new nanohybrids. The AuPd/GO composites display high electrocatalytic activity for the oxidation of ethanol in strongly alkaline medium as examined by cyclic voltammetry and chronoamperometry. Both the current density (13.16 mA · cm at a working potential of −0.12 V) and the long-time stability are superior to a commercial Pd-on-carbon catalyst which is attributed to the cooperative action of the catalytic activities of Au and Pd, and the good dispersion of the alloy on the nanosheets. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Flower-shape palladium nanostructures have been synthesized on the surface of graphene oxide by a simple effective method in the absence of any reducing chemical reagent. Atomic force microscopy (AFM), and Fourier transform infrared spectra (FT-IR) were used to characterize GO. The flower-shape palladium/Graphene oxide (FS-Pd/GO) nanocomposites are characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD). As-prepared FS-Pd/GO nanocomposites exhibited excellent performance on the electrocatalytic oxygen reduction reaction (ORR) and the glucose oxidation reaction. This method may open a general approach for preparing metal nanostructures on GO sheets for applications in fuel cells, biosensing and other fields. [Copyright &y& Elsevier]

Graphene oxide nanosheet is an ideal platform to capture nanoparticles for highly efficient catalysis, electrochemical sensing and biosensing. In this work, we have described a simple synthesis method for preparation graphene oxide- nanohybrid. nanodots with an average size of 1.6 nm uniformly dispersed on the surface of graphene oxide. The well-defined nanostructure has been characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The nanohybrid also exhibits enhanced catalytic activity toward the reduction of 4-nitrophenol by . Comparing with pure nanodots and graphene oxide, graphene oxide- nanohybrid shows the highest catalytic activity. This approach not only suggests a wide potential application of graphene oxide nanosheet as a host material for supporting a variety of nanoparticles, but also provides a new approach for the fabrication of graphene-based nanohybrids with multiple physical and chemical properties. Graphene oxide-Au nanohybrid has been prepared to enhance the catalytic activity toward the reduction of 4-nitrophenol. [ABSTRACT FROM AUTHOR]

Abstract: A convenient and efficient preparation method for separation graphene oxide with well-defined size distribution is developed using a centrifugation technique. The graded profile of graphene oxide nanosheets with narrow size distribution is effectively controlled by varying the centrifugation speed. The results show that the oxygen content of graphene oxide is highly dependent on their size distribution. Graphene oxide nanosheet with large size shows a red-shift in UV–vis absorption spectra, compared to graphene oxide with small size. This phenomenon is interpretation by a density functional theory calculation. The present work will provide a simple method to prepare graphene oxide nanosheets with controllable size distribution and C/O ratio, which will be valuable for the functionalization of graphene-based hybrids and the fabrication of graphene nano-devices. [Copyright &y& Elsevier]

Abstract: In the present study, a facile method is developed for the synthesis of graphene oxide-Ag nanocomposite (GOAg). The method involves the application of in situ photochemical deposition and growth processes under certain alkaline environments in the absence of chemical reductants and surfactants. Silver nanoparticles with monodisperse size are well dispersed on the surface of graphene oxide (GO). The roles of GO and NaOH in the formation of GOAg are discussed. A corresponding formation mechanism of GOAg is proposed. Fluorescence quenching and Raman enhancement are examined as well. [Copyright &y& Elsevier]

Abstract: A hybrid material of graphene oxide (GO) sheets beaded with ZnO nanoparticles was prepared. The material extends over a few hundred square nanometers, in which the ZnO nanoparticles (average diameter (∼5nm)) are dispersed evenly on the GO sheet. Both the surface photovoltage or surface photocurrent intensity for the material are much stronger than for pure ZnO nanoparticles, meaning that the free charge carriers can effectively be transferred from ZnO nanoparticles to GO sheets, which can serve as a probe to monitor the electron transfer from excited ZnO to GO. Anchoring ZnO nanoparticles on two dimensional carbon nanostructures such as GO can pave a way towards the design of ordered nanostructure assemblies that can harvest light energy efficiently. [Copyright &y& Elsevier]