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Study On Carbon-shell State Metal Oxide/metal@graphene Composite Materials: Preparation, Characterization And Properties

Posted on:2016-03-07Degree:MasterType:Thesis
Country:ChinaCandidate:H DuFull Text:PDF
GTID:2191330461450794Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
The metal oxide/metal-carbon@graphene composites were synthesized via a chemical deposition-carbonbotuermic-hudrothermal method by using graphene oxide(GO) as a precursor. The nanocomposites were characterized by transmission electron microscopy(TEM), X-ray power diffraction(XRD), Raman spectra, Fourier transform infrared(FTIR) spectroscopy, and X-ray photoelectron spectroscopy(XPS). Also we investigated their structures and physico chemical properties, involving in superparamagnetic performance, lithium ion batteries(LIBs) anode materials performance, hydrogen production and pollutant adsorbent performance.A three-dimensional Ni–carbon–r GO(NGC) nanocomposite was synthesized through a hydrothermal process followed by carbonthermal reduction. The magnetic Ni nanoparticles(NPs) encapsulated in carbon shells were anchored onto reduced graphene oxide(r GO) sheets. This NGC was used as an adsorbent for rhodamine B(Rh-B) removal. Compared with other adsorbent materials, NGC exhibits higher adsorption rate and efficiency up to 4.4 L·g–1 with good recyclability. The intrinsic superparamagnetism endows NGC enhanced separation efficiency with large adsorption capacity. The excellent removal ability for organic dyes makes NGC a useful candidate for wastewater treatment. FCG composite was synthesized through a hydrothermal process followed by carbonthermal reduction. Due to the coexistence of carbon shells and r GO sheets, FCG possesses superior structure stability with high surface area and excellent conductivity. As anode material for LIBs, the cycle performance of FCG has been determined for 300 cycles with high capacity and excellent cycle stability. Further electrochemical test results showed that a specific discharge capacity of 549 m A·h·g–1 after 300 cycles at current rate of 0.2 C. NPG composite was synthesized by anchoring Ni(OH)2 nanoparticles(NPs) onto the r-GO sheets before polymerization of the aniline. Electrochemical measurements of the composite material show NPG is suitable for working under low charge and discharge rate, the stability of NPG needs to be improved still. NNG composite was synthesized by annealing of NPG. Electrochemical measurements of the composite material show NPG is suitable for working under low charge and discharge rate, the stability of NPG needs to be improved still.
Keywords/Search Tags:core-shell structure, graphene, lithium ion batteries, hydrogen production, adsorption separation, metal oxide
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