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TiO2 nanotubes were produced by anodisation of pure titanium foil in a standard two-electrode bath consisting of either 1 M Na2SO4 or glycerol solution containing 5 wt% NH4F. The effect of anodisation voltage applied to the foil was studied to investigate the possibility of controlling the dimensions of the nanotubes produced. It was found that, in both electrochemical baths the diameter of the nanotubes increases with increasing of the applied voltage. However, in 1 M Na2SO4 there appears to be a maximum voltage at which the nanotubular structure persists. The maximum applied voltage must be less than 30 V. Above this voltage, the nanotubular structure is destroyed leaving an oxide with porous-like morphology. In glycerol bath, the maximum voltage is higher. The length of the nanotubes was also found to be dependent on the voltage. In glycerol, the length of the nanotubes increases from 200 nm to 700 nm as the anodisation voltage was increased from 10 to 30 V. [ABSTRACT FROM AUTHOR]

Oxidation of cube textured (100) <001> Ni and Ni-5%W foils were studied in order to verify if NiO surface layer could be formed on Ni-W similar to that Ni. The principle aim of this study is to prescribe the basic conditions for growing a compact, adherent, smooth, and cube texture NiO suitable to be used as a buffer layer in coated conductor, high temperature superconductor architecture. It was found that for Ni 30 μm thick (002) NiO were formed at oxidation temperature of 1250±10 °C in air for 60 min. Under the same oxidation condition, (002) NiO with duplex-type morphology was formed on Ni-5%W which reduces the mechanical integrity of the sample. Furthermore, due to oxygen diffusion during the oxidation process, spherical NiWO4 formed inside the Ni-W substrate. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) nanostructured titania such as nanowires, nanorod and nanotubes have attracted considerable attention recently due to their unique physical properties and their potential application in water photoelectrolysis, photocatalysis, gas sensing, and photovoltaic. In this work, a simple anodisation method has been developed to fabricate titania nanotubes in 1M Na2SO4 containing various amount of NH4F. The dimension of the titania nanotube produced depend on the electrochemical process parameter: composition of the electrolyte, pH of the electrolyte and time of anodisation. As for this paper, the effect of fluoride content and anodisation time on the formation of titania nanotube was discussed in detail. The nanotubes formed were analyzed by field emission scanning electron microscope (FESEM) and X-Ray diffraction (XRD). The minimum fluoride content that is required to form nice well ordered nanotube for sample anodized for 30 minutes is 0.3g whereas for 120 minutes is 0.1g. [ABSTRACT FROM AUTHOR]