Preparation And Photoeiectrochemical Study Of TiO₂ Nanotubes And Nanowires

In this dissertation,TiO₂ nanotubes and nanowires were prepared with a hydrothrmal method in which titanium foil deposited with TiO₂ nanoparticles was used.By controlling reaction temperature,TiO₂ nanotubes and nanowires could be obtained.The photoelectrochemical properties of the pure TiO₂ nanotubes and nanowires were investigated respectively.The experiment results showed as follows:TiO₂ nanotubes were prepared with a hydrothermal method at 170℃,for 48 h. TiO₂ nanotubes were ca.20～200 nm in out-diameter,several micrometers to tens in length. TiO₂ nanowires were prepared with a hydrothermal at 180℃.TiO₂ nanowire is about 20～50 nm and the length up to several micrometers.The temperature affects remarkably on the size and the morphology of TiO₂ nanowires.The diameter and the length of nanowire increases with the increase in temperature.The photoelectrochemical properties of the TiO₂ nanotubes and nanowires were compared.TiO₂ nanotubes and nanowires both produced anodic photocurrent,exhibiting the property of the n-type semiconductor.Compared with TiO₂ nanowires,TiO₂ nanotubes have two opening ends of the hollow tubular structure and the layered structure of the wall for the rapid migration of electronic.The surface area of TiO₂ nanotubes is about twice than the nanowires.The photoelectrical results show that the photoelectron- chemical properties of TiO₂ nanotubes was better than TiO₂ nanowires.The photoelectrochemical properties of the TiO₂ nanotubes and nanowires/PMeT were investigated.The results showed that the Iph of TiO₂ nanotubes/PMeT had the maximum value at -0.7 V,the Iph TiO₂ nanowires/PMeT had the maximum value at -0.6 V.The p-n heterojunction was existed in the TiO₂ nanotubes and nanowires/PMeT film electrode.Photocurrent of PMeT modified TiO₂ nanotubes and nanowires was higher than that of TiO₂ nanotubes and nanowires film electrode in long wavelength region.