Preparation And Photoelectric Properties Of CuO Nanomaterials

Copper oxide semiconductor materials have the advantages of rich natural resources,low price,non-toxic and harmless,and narrow forbidden band width.CuO has a band gap of about 1.7 e V and Cu₂O has a band gap of about 2.2 e V.Both are direct-bandgap semiconductor materials.They have excellent absorption characteristics for visible light and have broad application prospects in photocatalysis and solar cells.Nanostructured metal oxides have a very large specific surface area,and they have excellent physical and chemical properties due to size effects.In this thesis,four types of thin film materials,namely nanospheres,nanoears,corn leaf-like nanosheets and maple leaf-like nanosheets,were prepared on conductive glass ITO and Cu foil.X-ray diffractometer?XRD?,X-ray photoelectron spectroscopy?XPS?,field emission scanning electron microscopy?FE-SEM?,high-resolution transmission electron microscopy?HR-TEM?,and ultraviolet-visible diffuse reflection spectroscopy?UV-vis?The structure,composition,surface morphology and light absorption properties of the samples were characterized,and the photoelectric properties of the films were analyzed by photocurrent response testing.The main research contents are as follows:1.Using a mixed solution of copper acetate?Cu?CH₃COO?₂?and disodium ethylenediamine tetraacetate?EDTA-2Na?as the electrolyte,a spherical Cu/Cu₂O/CuO nanometer was prepared on the ITO substrate by a one-step electrochemical deposition method Array film.The synthesis conditions of spherical morphology were investigated by FE-SEM.When the concentration of Cu?CH₃COO?₂ was 10 mmol/L,the concentration of EDTA-2Na was 1.25 mmol/L,the deposition potential was-0.9 V,and the deposition time was spherical.Optimal conditions for appearance synthesis.The samples were annealed at different temperatures by thermal oxidation to investigate the effects of annealing temperature on the composition,morphology,and photoelectric properties of the films.The results show that as the annealing temperature increases,the film composition changes to CuO at 350 ?,and the morphology of the film surface becomes rougher as the annealing temperature increases,and the nanosphere array film obtained after annealing at 350 ? shows the most excellent photoelectric response performance.2.A wheat-like Cu/Cu₂O/CuO nano-array thin film was prepared on the ITO substrate by an electrochemical deposition method using a mixed solution of Cu?CH₃COO?₂ and EDTA-2Na as an electrolyte.FE-SEM was used to investigate the synthetic conditions of wheat spike shape.When the concentration of Cu?CH₃COO?₂ was 20 mmol/L,the concentration of EDTA-2Na was 2.5 mmol/L,the deposition potential was-1.0 V,and the deposition time was optimal conditions for the synthesis of wheat spike shape.The samples were annealed at different temperatures by thermal oxidation to investigate the effects of temperature on the composition,morphology,and photoelectric properties of the films.The results show that with the increase of annealing temperature,the film composition changes to CuO at 350 ?.And the nanostructure of the film collapsed with the increase of the annealing temperature.The nano-wheat array film obtained after annealing at 350 ? showed the best photoelectric response performance.3.A sheet-like Cu₂O film was prepared on the Cu foil substrate by using anodization with potassium hydroxide?KOH?as a single electrolyte.The synthesis conditions of corn leaf-shaped nanoflakes were investigated by FE-SEM.The optimum conditions for the synthesis of corn leaf morphology were KOH concentration of 4 mol / L,voltage of 0.7 V,and oxidation time of 60 min.The samples were annealed at different temperatures by thermal oxidation to investigate the effects of temperature on the composition,morphology,and photoelectric properties of the films.The results show that with the increase of annealing temperature,the film composition is completely changed to CuO at 350 °C,and the morphology of the film is gradually roughened with increasing temperature.Best photoelectric response performance.By increasing the voltage to 0.8 V and keeping other experimental conditions unchanged,a maple leaf-like nanosheet structure was prepared and compared with corn leaf-like nanosheets in terms of photoelectric performance.In the end,corn leaf-like nanosheets showed better photoelectric performance.