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Nickel decorated vertically aligned graphene sheets (VGSN1) and vertically aligned graphene sheets-graphene shell/nickel core (VGSN2) hybrids have been synthesized by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD). The surface morphology, microstructure and growth mechanisms of VGSN1 and VGSN2 hybrids were investigated. The field emission (FE) studies indicated that the graphene-Ni hybrids delivered better FE performance than pristine graphene (VGS/Si) due to the insert of Ni particles. The influences of the morphologies and structures on FE performance have been revealed. Our approach provides a novel way to fabricate highly efficient graphene-based field emitters for the development of practical electron sources. [ABSTRACT FROM AUTHOR]

N, S co-doped graphene quantum dots (N, S-GQDs) -reduced graphene oxide- (rGO) -TiO 2 nanotubes (TiO 2 NT) composites were prepared by a facile alkaline hydrothermal reaction and physical stirring process. The apparent rate constant of the N, S-GQDs+10%rGO + TiO 2 NT composite, exhibiting the highest photodegradation efficiency, is 1.8 times and 16.3 times higher than those of 10%rGO + TiO 2 NT and pure TiO 2 NT, respectively, for the degradation of methyl orange (MO) under visible light irradiation (λ > 400 nm). Our work could provide new insights into the fabrication of GQDs-semiconductor composites as high performance photocatalysts and broaden the range of doped GQDs widely used for environmental protection. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we have developed a simple and green method for one-pot synthesis of ultrathin gold nanocrystals attached to graphene through photo irradiation. High-yield ultrathin Au nanocrystals are distributed on the reduced graphene oxide, immediately followed by the deoxygenation of graphene oxide in the absence of chemical reductants and surfactants. The procedure has been thoroughly completed and the products have been analyzed by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), etc. The results show that both graphene oxide and photo irradiation play essential roles in the formation of ultrathin Au nanocrystals. The nanohybrids also display excellent electro-catalytical performance to methanol oxidation. This study not only has potential in the applications of bio-sensing and fuel cells, but also provides new procedures for the preparation of metal/graphene nanomaterials. [Copyright &y& Elsevier]

Abstract: Reduced graphene oxide/cadmium sulfide (RGO/CdS) hybrid material was synthesized by a one-step solvothermal method, wherein graphene oxide (GO) was a supporting material on which CdS nanoparticles were distributed homogeneously, and cadmium acetate (Cd(Ac)2·2H2O) was used as the CdS precursor. The supporting material RGO for CdS nanoparticles effectively enhanced their photocatalytic activities for the photodegradation of methylene blue in the aqueous solution. The optimum weight ratio of the GO to CdS in the hybrid material was 5.0%, which exhibited an excellent photodegradation efficiency (94%) and a better removal efficiency of total organic carbon (TOC) (57%), about 2.5 times and 5.1 times higher than that of pure CdS nanoparticles, respectively, under visible light (VL) irradiation. This improved photodegradation efficiency could be attributed to the increased adsorbability for methylene blue molecules, light absorption levels located in visible region, high charge transfer and separation ability, due to the introduction of a two-dimensional RGO network. [Copyright &y& Elsevier]

Abstract: A novel hedgehog-like core/shell structure, consisting of a high density of vertically aligned graphene sheets and a thin graphene shell/a copper core (VGs-GS/CC), has been synthesized via a simple one-step synthesis route using radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD). Scanning and transmission electron microscopy investigations show that the morphology of this core/shell material could be controlled by deposition time. For a short deposition time, only multilayer graphene shell tightly surrounds the copper particle, while as the deposition time is relative long, graphene sheets extend from the surface of GS/CC. The GS can protect CC particles from oxidation. The growth mechanism for the obtained GS/CC and VGs-GS/CC has been revealed. Compared to VGs, VGs-GS/CC material exhibits a better electron field emission property. This investigation opens a possibility for designing a core/shell structure of different carbon–metal hybrid materials for a wide variety of practical applications. [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]