The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Tianxi Liu - One of the best experts on this subject based on the ideXlab platform.
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one step preparation of hierarchical superparamagnetic iron oxide graphene composites via Hydrothermal Method
Applied Surface Science, 2011Co-Authors: Lulu Ren, Shu Huang, Wei Fan, Tianxi LiuAbstract:Abstract In this paper, graphene/magnetite composites with hierarchical Fe3O4 structures were synthesized via a one-step Hydrothermal Method. The size of Fe3O4 nanocrystals and nanocrystal clusters can easily be controlled by altering reaction time and the starting mixed solvent ratio, respectively. Raman measurements evidenced that graphene oxide was simultaneously reduced to graphene during the deposition of magnetite particles. The deposition of Fe3O4 nanocrystals and nanocrystal clusters impedes graphene to restore the graphite structure. The composites showed a high crystallinity of magnetite and a considerable saturation magnetization. Furthermore, the acrylate modified Fe3O4 makes the composites water-dispersible and can effectively load polyfluorene polyelectrolyte via electrostatic force. The high magnetism, excellent water dispersibility and strong photoluminescence make these composites ideal candidates for various important applications such as magnetic resonance imaging, bioseparation, bioimaging, and optical devices fabrication.
Mujie Yang - One of the best experts on this subject based on the ideXlab platform.
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tin oxide graphene composite fabricated via a Hydrothermal Method for gas sensors working at room temperature
Sensors and Actuators B-chemical, 2012Co-Authors: Qianqian Lin, Mujie YangAbstract:Abstract SnO2/graphene (GN) composite was fabricated via a simple one-pot Hydrothermal Method with graphene oxide (GO) and SnCl2 as the precursors. The composite was characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction patterns, scanning electron microscopy and high resolution transmittance electron microscopy. It exhibited 3D nanostructure in which flower-like microspheres consisting of SnO2 nanoflakes distributed among GN layers decorated with tiny SnO2 nanoparticles, and was featured with high surface area (94.9 m2/g). GO is supposed to act as a template in the Hydrothermal process, promoting the preferential growth of SnO2 nanocrystals and preventing the agglomeration of SnO2 nanoparticles. NH3 sensing characteristics of the composite at room temperature were investigated, and found to closely relate to its composition and structure. Under optimal conditions, the composite displayed high response magnitude (15.9% for 50 ppm NH3), fast response (response and recovery time
Yanfei Sun - One of the best experts on this subject based on the ideXlab platform.
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pyrite fes2 films prepared via sol gel Hydrothermal Method combined with electrophoretic deposition epd
Materials Research Bulletin, 2004Co-Authors: Haiming Duan, Yufeng Zheng, Y Z Dong, X G Zhang, Yanfei SunAbstract:Pyrite FeS2 powder was initially synthesized using sol–gel Hydrothermal Method by the reaction of S and the colloid precursor formed from FeSO4·7H2O and thiourea fluxes. We present some results on the influence of reactants, reaction temperature and time, and the quantity of S on the formation of single-phase pyrite FeS2 powder. Then EPD technique was applied to the deposited as-prepared pyrite powder. Crystal structure, optical and electrical property measurements for the pyrite films prepared in this way were carried out and some special results have been obtained.
K H Tam - One of the best experts on this subject based on the ideXlab platform.
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antibacterial activity of zno nanorods prepared by a Hydrothermal Method
Thin Solid Films, 2008Co-Authors: K H Tam, Yu Hang Leung, Aleksandra B Djurisic, W K Chan, Charis M N Chan, C W Tse, Frederick C LeungAbstract:Abstract We investigated antibacterial activity of ZnO nanorods prepared by a Hydrothermal Method against a gram-negative bacterium Escherichia coli and a gram-positive bacterium Bacillus atrophaeus . Antibacterial activity of ZnO nanorod coatings was studied on solid substrates covered with nutrient agar, as well as in liquid nutrient broth for different concentrations of ZnO nanorods, nanoparticles, and powder. ZnO exhibited antibacterial activity against both E. coli and B. atrophaeus , but it was considerably more effective in the latter case (at 15 mM vs. 5 mM concentration, respectively, showing zero viable cell count). For both organisms, damage of the cell membranes was found, and the effect was more pronounced for B. atrophaeus . Chemiluminescence analysis has been used to detect the release of hydrogen peroxide from ZnO structures, and the effect of H 2 O 2 on the E. coli and B. atrophaeus was studied. Since significant differences were observed in the effect of ZnO nanostructures and H 2 O 2 on B. atrophaeus , it can be concluded that there are other mechanisms contributing to the antibacterial activity of ZnO nanostructures.
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defects in zno nanorods prepared by a Hydrothermal Method
Journal of Physical Chemistry B, 2006Co-Authors: K H Tam, C K Cheung, Yu Hang Leung, Aleksandra B Djurisic, C C Ling, C D Beling, S Fung, Wai Ming Kwok, W K Chan, D L PhillipsAbstract:ZnO nanorod arrays were fabricated using a Hydrothermal Method. The nanorods were studied by scanning electron microscopy, photoluminescence (PL), time-resolved PL, X-ray photoelectron spectroscopy, and positron annihilation spectroscopy before and after annealing in different environments and at different temperatures. Annealing atmosphere and temperature had significant effects on the PL spectrum, while in all cases the positron diffusion length and PL decay times were increased. We found that, while the defect emission can be significantly reduced by annealing at 200 °C, the rods still have large defect concentrations as confirmed by their low positron diffusion length and short PL decay time constants.
Lulu Ren - One of the best experts on this subject based on the ideXlab platform.
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one step preparation of hierarchical superparamagnetic iron oxide graphene composites via Hydrothermal Method
Applied Surface Science, 2011Co-Authors: Lulu Ren, Shu Huang, Wei Fan, Tianxi LiuAbstract:Abstract In this paper, graphene/magnetite composites with hierarchical Fe3O4 structures were synthesized via a one-step Hydrothermal Method. The size of Fe3O4 nanocrystals and nanocrystal clusters can easily be controlled by altering reaction time and the starting mixed solvent ratio, respectively. Raman measurements evidenced that graphene oxide was simultaneously reduced to graphene during the deposition of magnetite particles. The deposition of Fe3O4 nanocrystals and nanocrystal clusters impedes graphene to restore the graphite structure. The composites showed a high crystallinity of magnetite and a considerable saturation magnetization. Furthermore, the acrylate modified Fe3O4 makes the composites water-dispersible and can effectively load polyfluorene polyelectrolyte via electrostatic force. The high magnetism, excellent water dispersibility and strong photoluminescence make these composites ideal candidates for various important applications such as magnetic resonance imaging, bioseparation, bioimaging, and optical devices fabrication.
