Study On Metal Oxide@Graphite Carbon Nitride/Reduced Graphene Oxide Composite Materials:Preparation,Characterization And Properties | Posted on:2017-05-30 | Degree:Master | Type:Thesis | Country:China | Candidate:X J Zhang | Full Text:PDF | GTID:2271330485480443 | Subject:Industrial Catalysis | Abstract/Summary: | PDF Full Text Request | The metal oxide-carbon@graphene and double metal oxide@graphene composites were synthesized by using graphene oxide(GO) as a precursor. The metal/metal oxideGraphite carbon nitride(g-C3N4) composite was synthesized via a simple solid-state reaction route by using melamine as a precursor. We investigated their hydrogen production and lithium ion batteries anode materials performance(LIBs).Firstly, CoxOy@g-C3N4(CCN) composite was synthesized. Cobalt and cobalt oxide were loaded in the graphite carbon nitride(g-C3N4). CCN composite was used high active catalyst for hydrogen generation. CCN composites have super paramagnetic property due to the presence of cobalt nanoparticles. Furthermore, CCN composites can take place of magnetic stir to transfer magnetically momentum. The hydrogen production rate of the catalytic hydrolysis of sodium borohydride reached to 710 m L·min-1·g-1 on CCN composite at room temperature. The calculation of apparent activation energy reached to 41.2 k J·mol-1 by Arrhenius formula. CCN composite material also showed good cycle stability. The hydrogen production rate was improved due to the perfect combination of graphite carbon nitride and CoxOy. The super paramagnetic property and excellent catalysis warrant its application in some fields.Secondly, a three-dimensional TiO2-carbon-r GO(TCG) was fabricated and posttreated with UV irradiation(254 nm) for 0.5 h under the condition of air and nitrogen to obtain TCG-UV-AIR and TCG-UV-N2. The composites were characterized by Xray diffraction(XRD), Raman spectroscopy, X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM). The UV irradiation improved the crystalline properties of Ti O2 nanoparticles. Homogeneous UV irradiation improved the degree of graphitization of carbon in TCG-UV-AIR and TCG-UV-N2. The r GO sheets and carbon shells improved the electrical conductivity and structural stability of TCG, and as anode materials of lithium ion batteries, a higher specific discharge capacity of TCG-UV-N2 up to 261 m A·h·g-1 obtained after 200 cycles at a current rate of 0.2 C.Finally, we synthesized V2O5-Ti O2-r GO(VTG) composite, changed adding order of precursor of metal oxide to obtain TVG composite. The composites were characterized by X-ray diffraction(XRD), Raman spectroscopy, X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM). The degree of graphitization of carbon in VTG was improved. The r GO sheets improved the electrical conductivity and structural stability of VTG. As anode materials of lithium ion batteries, a higher specific discharge capacity of VTG composite up to 410 m A·h·g-1 were obtained after 200 cycles at a current rate of 0.2 C. | Keywords/Search Tags: | reduced graphene oxide, graphite carbon nitride, metal oxide, lithium ion batteries, hydrogen production | PDF Full Text Request | Related items |
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