Ordered TiO2 nanowire arrays have been successfully fabricated into the nanochannels of a porous anodic alumina membrane by sol–gel electrophoretic deposition. After annealing at 500°C, the TiO2 nanowire arrays and the individual nanowires were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and x-ray diffraction (XRD). SEM and TEM images show that these nanowires are dense and continuous with a uniform diameter throughout their entire length. XRD and SAED analysis together indicate that these TiO2 nanowires crystallize in the anatase polycrystalline structure. The optical absorption band edge of TiO2 nanowire arrays exhibits a blue shift with respect of that of the bulk TiO2 owing to the quantum size effect.

Films of nitrogen-doped TiO2 have been successfully deposited on a Si substrate by radio frequency reactive sputtering in a mixture of argon, oxygen and nitrogen. The nitrogen gas ratio varies in the range 0.2–0.4 during the deposition, resulting in TiOxNy films with 3% ≤ y ≤ 6.55% as determined by x-ray photoelectron spectroscopy (XPS). Chemical bond state analysis by XPS indicates that nitrogen is effectively incorporated and produces an oxynitride centre as oxygen is replaced by nitrogen. Characterization by atomic force microscopy demonstrates that the incorporation of nitrogen has a significant effect on the morphology of the targeted TiO2 thin films. Spectroscopic ellipsometry with a photon energy of 0.75–6.5 eV at room temperature has been carried out to derive the refractive index n and the extinction coefficient k on the basis of a new amorphous dispersive model. The optical constants such as absorption coefficient, complex dielectric functions and the optical band gap have been determined. The trend of a decrease in the optical band gap with an increase in nitrogen concentration is consistent with the observation determined by UV–visible spectroscopy. The reduced band gap is associated with the N 2p orbital in the TiOxNy films.

Strong photoluminescence bands range from 300 to 600 nm at room temperature have been observed in anodic alumina membranes (AAM). It was found that the photoluminescence (PL) intensity and peak position of AAM depend strongly on the excitation wavelength, and the PL intensity of AAM prepared in C2H2O4 is much higher than for AAM prepared in H2SO4. There are two peaks in the PL bands; one is at constant wavelength of 460 nm, and the other increases almost linearly from 420 to 465 nm with excitation wavelength for AAM prepared in C2H2O4 and from 360 to 465 nm for AAM prepared in H2SO4. Annealing treatment of the as-prepared AAM results in an apparent reduction of the intensity of the blue emission at shorter excitation wavelength, while at longer excitation wavelength (longer than 320 nm) the PL intensity firstly increases, and at 500 °C reaches a maximum value, then decreases. It is considered that there are two PL centres; one originates from the oxygen-related defects in the barrier layer, and the other is correlated with the aluminum incorporated into the anion-contaminated alumina layer in the AAM.

Large-scale single-crystalline CdO nanowires have been successfully fabricated from the electrochemical deposition mixture film of Cd and Te at 450°C, and characterized by x-ray diffraction (XRD) powder, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM images show that these nanowires are uniform with diameters of about 40–60 nm, length up to several tens micrometres. XRD and selected area electron diffraction analyses altogether indicate that these CdO nanowires crystallize in a NaCl cubic structure. The growth mechanism of these nanowires is also proposed as vapour–liquid–solid mechanism, in which Te serves as a liquid-forming agent.

Large-scale Y2O3:Eu nanotubes have been successfully fabricated by an improved sol–gel method within the nanochannels of porous anodic alumina templates. In this method, yttrium nitrate, europium nitrate and urea were used as precursors, yttrium nitrate and europium nitrate were acting as sources of europium and yttrium ions, and urea offered a basic medium through its hydrolysis. X-ray diffraction techniques, scanning electron microscopy, transmission electron microscopy and selected-area electron diffraction were used to characterize the Y2O3:Eu nanotubes obtained. It is found that the prepared Y2O3:Eu nanotubes can be indexed as a polycrystalline cubic structure and their outer diameters are about 50–80 nm, with the thickness of the tube wall estimated to be around 5 nm. The emission peaks of the as-prepared Y2O3:Eu nanotubes are broader than those of bulk Y2O3:Eu because of the disordering of the crystal phase possibly induced by the increase of the surface/volume ratio in the nanotubes.

High-k ZrO2 films were prepared by nitrogen-assisted direct current reactive magnetron sputtering on n-type silicon (100). The microstructure and optical properties in relation to thermal budgets were investigated. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical states. Atomic force microscopy (AFM) analysis indicated that the annealing temperature had significant effects on surface roughness. By using Fourier transform infrared spectroscopy (FTIR), the resistance to the interface growth after the additional thermal budgets was observed. The thickness and pseudodielectric constants of ZrO2 thin films correlating to annealing temperature were determined by Tauc–Lorentz spectroscopic ellipsometry (SE) dispersion model fitting. Optical band gaps (Eg) were also obtained based on the extracted absorption edge.

The mass preparation of SnO2 nanobelts and nanowires has been achieved by carrying out the reaction of SnO2 powder and graphite at 1150°C. A metallic catalyst and vacuum conditions are not necessary. The temperature of the substrates and the concentration of oxide vapour were the critical experimental parameters for the formation of different morphologies of SnO2 nanostructures. The as-synthesized SnO2 nanobelts formed in region II are single crystalline with a [101] growth axis, with widths ranging from 50 to 500 nm, width-to-thickness ratios of 5–10, and lengths up to a few millimetres.

Zn nanowires and nanoribbons have been synthesized from Zn powders through a simple thermal-vapour deposition process.