Shape-Controlled Synthesis And Study Of Properties Of Cuprous Oxide And Copper Submicro-And Nano-Structures

Controlled synthesis of nanomaterials has been received considerable attention inrecent years, due to the strong correlation between the shape and size of nanomaterialsand the physical and chemical properties of nanomaterials. However researchers find thatshape of nanomaterials have an important effect on properties of nanometerials.In this paper, various Cu₂O and Cu submicro-and nano-structures controlled weresynthesized by solution-phase and hydrothermal methods. The morphologies and phasestructure of the prepared products were investigated by field emission scanning electronmicroscopy （FE-SEM）, X-ray diffractometer （XRD）, transmission electron microscope（TEM） and energy dispersive spectrometer （EDS）. The optical properties of spherical andcubic Cu₂O nanoparticles were studied by UV-vis absoption spectrum. And photocatalyticdegredation of methylene bule of spherical nanoparticles was investigated. With Cu₂Oand Cu nanoparticles as catalyst, zonal, straight and helical carbon nanofibers weresynthesized by catalytic polymerization of acetylene. The growth mechanism of Cu₂Oparticles and Cu nanorods was also discussed. The main contents are as follows:1. Shape-controlled synthesis of nanostructures of Cu₂O and CuCu₂O submicro-and nanoparticles were synthesized by solution-phase method,reducing Cu（NO₃）₂·3H₂O with ethylene glycol in present of poly （vinylypyrrolidone）（PVP）. Various Cu₂O structures had been synthesized by altering the concentration ofcopper nitrate and PVP molar ratio （in repeating unit） relative to copper nitrate. At lowconcentration of copper nitrate （≤0.06M） and the molar ratios of PVP/Cu（NO₃）₂ 10～15,cubic nanoparticles with an average size of 120 nm were synthesized; at highconcentration of copper nitrate （0.06～0.12M） and the molar ratios of PVP/Cu（NO₃）₂5～7,spherical particles with an average size of 250 nm were prepared. And copper nanorodswith average diameter of 70 nm and aspect ratio of 7 were obtained at the concentration of copper nitrate about 0.15 M and the molar ratios of PVP/Cu（NO₃）₂ 2～3.Copper nanorods and flower-like nanostructures were synthesized by a simplehydrothermal method under alkaline condition, reducing copper nitrate with ethylene glycol inthe presence of PVP. The diameter and length of copper nanorods are 60 nm and 300 nmrespectively. And flower-like nanostructures consisted of some copper nanorods withaverage diameter and length of 80 nm and 200 nm. Copper nanoparticles with averagesize of 100 nm were synthesized by altering pH of the reactive solution. Coppernanoflakes were prepared with SDBS as surfactant.Copper dodecylbenzenesulphonate were prepared with sodium dodecylbenzene-sulphonate and copper sulfate in a water bath at 0℃. Copper nanoparticles, with anaverage size about 20 nm, were synthesized by reducing copper dodecyl-benzenesulphonate with NaBH₄ at the ultrasonic pool. Nanoparticles with various sizeswere prepared by altering the concentration of NaBH₄.2. Optical, Photocatalytic and catalytic properties of Cu₂OThe optical properties of spherical and cubic Cu₂O nanoparticles were studied byUV-vis absoption spectrum, and the band gap of cubic Cu₂O nanoparticles was calculatedalso. And photocatalytic degredation of methylene bule of spherical Cu₂O nanoparticlessuspension irradiated by visible light was investigated. With cubic Cu₂O particles ascatalysts, zonal and helical carbon fibers were synthesized; with spherical Cu₂Onanoparticles as catalysts, Straight carbon fibers with uniform diameter were synthesized.3. Catalytic property of Cu nanoparticlesCatalytic property of Cubic and spherical Cu nanoparticles was studied by catalyticpolymerization of acetylene. Zonal carbon nanofibers were synthesized with cubicnanoparticles as catalysts. With sphereical Cu nanoparticles （20～100 nm） as catalysts,helical carbon nanofibers were synthesized.However straight carbon fibers were obtainedwith spherical Cu submicroparticles （100～300 nm） as catalysts.