Synthesis Nickel Nanocomposites And Their Properties On Electrocatalytic Oxidation Of Organic Small Molecules

In this thesis, the microwave method, reflux method and solvothermal synthesis have been developed to synthesize nanostructured materials. By using of microwave method, graphene/nickel nanoparticle carbon matrix composites were synthesized. NiS and Ni(OH)2nano-materials were compounded through solvothermal synthesis. Using the reflow method, nickel nanowires and Ni3S2nanowires were synthesized. Respectively, their electrochemical properties were studied. Also there is a found that nickel ions induced solvothermal synthesis of WO3·0.5H2O octahedral. The main contents are as follows:1. A facile one-step microwave-assisted method for deposition of monodisperse Ni nanospheres on reduced graphene oxide (rGO) sheets to form Ni-rGO nanohybrids is discussed. In the presence of hydrazine monohydrate, Ni nanospheres are grown onto rGO sheets using nickel precursor and GO as starting materials in ethylene glycol (EG) solution under a low level of microwave irradiation (300W) for20min, during which GO is also reduced to rGO. The as-prepared nanohybrids exhibit well-dispersed Ni nanosphere (about80nm in diameter) loadings and effective reduction of graphene oxide. The resulting Ni-rGO nanohybrids-modified glassy carbon electrode (GCE) shows significantly improved electrochemical performance in nonenzymatic interfering species under physiological conditions, such as ascorbic acid (AA) and uric acid.2. Nickel nitrate (Ni(NO3)2·6H2O) and thiourea as reactants, ethylene glycol (EG) as solvent, PVP controlling morphology, by the solvothermal method NiS nanomaterials were compounded. Their performance of the electro-catalytic oxidation of methanol was studied. The results show that the nickel sulfide has superior performance than Ni(OH)2. Mainly: in alkaline solution NiS is more stable at the same potential than Ni(OH)2, NiS of oxidation current of the methanol electro-catalytic oxidation is greater than Ni(OH)2. in a methanol fuel cell NiS has a wider range of potential applications than Ni(OH)2.3. This work mainly elaborates the advantage of nickel sulfide for the catalytic methanol in alkaline medium compared with Ni(OH)2. The performance difference of Ni nanowires before and after sulfurization was compared. Ni3S2shows hydroxylated phenomenon in scans of multiple intervals. Their composition, morphology, and structure were characterized by the techniques such as scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The reaction mechanism is tentatively given. Nickel sulfide is expected to be a potential anode material in the methanol fuel cell.4. Using a mixed solution of water and ethanol in the case of nickel ions, Na2WO4at180℃generated WO3·0.5H2O octahedral, which can dehydrate generating of WO3, and can also be used as templates. It has a wide range of applications in photocatalysis and other fields potentially. The growth mechanism was conducted by a preliminary exploration.