Electrochemical Synthesis Of CuO And ZnO One-Dimensional Materials And First-Principles

Metal oxide one-dimensional materials is a new type of functional materials in the high and new technology, which is a very important part in the materials field. CuO and ZnO one-dimensional materials have broad application prospects, because of their excellent performance in photoelectric catalytic and battery materials.CuO and ZnO one-dimensional materials are prepared successfully by the electrochemical method which is a method of normal temperature and pressure. The main research contents are showed that:(1) The CuO nanowires and nanotubes are prepared successfully by direct current on aluminum oxide template in the Ionic liquids. The composition and morphology of the CuO nanowires and nanotubes were determined by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy spectrum analysis (EDS). The influence of anodization times and enlarge hole time for template were investigated. And the preparation mechanism of aluminum oxide template and one-dimensional material were discussed; (2)Direct oxidation method was used to prepare CuO and ZnO one-dimensional materials. The composition and morphology was characterized by SEM, XRD and EDS. cycle voltammetric curve was characterized by Electrochemical workstation to study the electrochemical process. The influence of oxidation time, electrolyte concentration, current density and additives factors were investigated; (3) The microstructure of CuO nanowires was calculated by first-principle based on the density functional theory. Results show that:1. Through the SEM images we know the AAO template with pore diameters of 80nm, and with a density of pores 1011/cm2; The CuO nanotubes are 3-4μm long, each with a diameter of 80nm, The CuO nanowires are 3-4μm long, each with a diameter of 80nm. The suitable processing conditions to prepare aluminum oxide template is:the temperature is controlled from 0 to 5℃, anodization voltage is 40V, the concentration of oxalic acid is 0.3mol/L, anodization time is 8h with two-steps, enlarge hole time is 40min in H3PO4; The suitable processing conditions to prepare CuO nanotubes is:the temperature is controlled from 40 to 55℃, the Current density is 5mA/cm2, electro-deposition time is 30min on the aluminum oxide'template; And CuO nanowires will be prepared when the electro-deposition time extend to 100min.2. Through the SEM images we know the CuO nanowires are 8-10μm with a diameter of 100nm, CuO whiskers are 1μm with a diameter of 90nm and CuO nanorod can be prepared successfully by changing the conditions use the direct oxidation method.3. Pine needle ZnO crystal whiskers were electrodeposited by anodization of zinc foil. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the crystal whiskers. The results show that the ZnO crystal whiskers have a length of 200-300nm with a diameter of 20-50nm and the ratio of the length to the diameter ranges from 10 to 15, the whiskers were wurtzite crystalline ZnO (JCPDS 36-1451) with good crystallinity and high purity. The electrochemical behavior of the process was discussed by cyclic voltammetry, the influences of the oxide layer on the zinc surface and the [Zn(OH) 4]2- concentration of the aqueous electrolyte on the formation of zinc oxide whiskers were investigated.4. Structural properties, electronic structure, electron density difference, mulliken changes were calculated using the first-principles based on density functional theory. Calculated bulk CuO remain monoclinic. But CuO nanowires unit cell is a triclinic one. Compared with the bulk CuO, Cu-0 bond length of nanowires CuO decrease, which show that the bonding strength of nanowires CuO is larger than bulk CuO. The theory calculation results provide the theory basis for CuO one-dimensional material design, structure, performance prediction and application.