Preparations And Properties Of One-dimension Nanomaterials By Template Method

As one-dimension nanomaterials have large specific area and high surface energy, they are widely used in catalysis area. Comparing with the bulk materials, one-dimensional semiconductors reveal novel properties. The photoresponse of single semiconductor is narrow, and the photoexcited electron/hole pairs will recombine rapidly. Composite semiconductors can overcome the above disadvantages, and become photocatalyst with predominant property.In this dissertation, we fabricated one-dimension semiconductor nanowires, nanotubes and alloy nanowires array in the nanochannels of aluminum anodic oxide membrane (AAO) by electrochemical and chemical technique successfully. We characterized their morphologies and structures by SEM and XRD, investigated the effects of processing to the catalysis property of one-dimensional nanomaterials, and studied the influencing factors and the preparation mechanism.High ordinal aluminum anodic oxide membranes were fabricated in the oxalic acid electrolyte, by twice processes of the anodic oxidation. It was found that didn't dissolve the barrier layer and deposite metal film during preparation of AAO, and CdS nanowires were prepared by dc electrodeposition in holes of AAO template. The lengths of the nanowires are more than 10μm. We found that in the condition of using double catalysts and 2mL H2O2, the catalysis property of CdS nanowires of smallest diameter treated under 650℃was better.TiO₂ nanotubes were prepared by the sol-gel method in holes of AAO template, and the length was more than 1μm. The catalysis property of TiO₂ nanotubes of biggest diameter treated under 550℃was better. Using both sol-gel method and dc electrodeposition we prepared CdS nanowires compositing with TiO₂ nanotubes and CdS nanowires compositing with TiO₂ film in AAO template. The catalysis property of CdS nanowires composites with TiO₂ nanotubes of biggest diameter treated under 550℃was better; and the catalysis property of CdS nanowires composites with TiO₂ film of smallest diameter treated under 650℃was better. In the same condition, the catalysis property of CdS nanowires composites with TiO₂ nanotubes was the best. The Ni-W-P alloy nanowires arrays were prepared in the AAO template by electrodeposition. These nanowires had uniform diameters of about 100nm, accorded with diameter of holes, and the length was about 20μm. We use electrochemistry workstation to test the cathodic polarization curve and AC Impedance spectra of Ni-W-P nanowires in 1mol/L NaOH aqueous. The experimental results showed that the overpotential for HER of the nanowires array electrode is 250mV lower than that of Ni-W-P alloy electrode, the former shows better properties for hydrogen evolution.