Papers by Keyword: TiO2

Abstract: Titanium is a lightweight metal with an outstanding combination of properties which make it the material of choice for many different applications. This paper investigates the structure, surface characteristics and electrical properties of the Titanium Dioxide (TiO₂) thin film, deposited by chemical vapor deposition (CVD). The deposition temperature was 1000°C with 3 different positions of the glass substrates. The surface morphologies were examined using a field emission scanning electron microscope (FESEM) and an atomic force microscopy (AFM). In order to investigate the structural properties, the TiO₂ thickness was measured using a surface profiler. The optical properties of TiO₂ were measured using an ultraviolet visible spectroscopy (UV-Vis). The surface morphology was found to be sensitive to the deposition parameters and the growth TiO₂ is more uniform when the position of substrate is closed to the starting material.

Abstract: Titanium Dioxide film will be deposited on a glass slide substrate by spin coating technique which is the frequently used technique because of its easy operation and cheap due to the sol gel preparation. The deposited films were then characterized by cross section technique using Field Emission Scanning Electron Microscopy (FESEM) to investigate the thickness based on the number of coatings. Then by the same FESEM, the surface morphology was studied to see the grain size and the porosity of each film based on the number of coatings. AFM was used to see the uniformity of the thin film's surface. Then by using current voltage (IV) measurement, the electrical property of the film can be studied, from IV characterization the resistivity of the film will be calculated. In this investigation, it is found that by increasing the coating layer, the resistivity values were decreasing whereas the conductivity of the film is increasing since conductivity is the inverse of resistivity. The porosity of the film also increases with the coating layers.

Abstract: Pure and doped Titania nanotubes (TiO2 NTs) photoanodes were fabricated by means of anodization method. The anodization was carried out in electrolytes prepared by mixing ethylene glycol (EG), ammonium fluoride (0.3 wt % NH4F) and deionized water (2 Vol % H2O) with different concentrations of dopant Fe (NO3)3∙9H2O. A constant dc power supply of 50 V was used as anodic voltage. The samples were annealed at 450 °C for 2 hours. The resultant products were characterized by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) to determine their microstructures when TiO2 NTs were doped with different amounts of Fe atoms. The diameters of TiO2 NTs were about 60-120 nm. The highest density of TiO2 NTs was obtained when the nanotubes were doped with 0.01 M of Fe. The photocatalytic activity was examined without external applied potential. The maximum photocurrent density was 3.0 mA/cm² under illumination of 100 mW/cm².

Abstract: There are plenty of intrinsic cation states on the surface of nano-semiconductor crystals. When the crystals contact the transformer oil，surface states that can capture electrons easily are formed. In this paper, TiO2 nano-powders with different surface modifications have been used to improve the property of transformer oil (Karamay 25#). The modification effects of nano-power’s on insulating property of transformer oils have been investigated. And the modifying effects of TiO2 nano-powder with different concentrations on transformer oil have been studied. The breakdown property tests and fitting results show that TiO2 nano-powder can improve the breakdown properties of transformer oil and within some concentrations，the higher the concentration of TiO2 nano-powder，the better the power frequency insulating property of modifying transformer oil. Besides，The modifying agents play a key role in the dispensability of TiO2 nano-powder in the transformer oil. With the increasing of nonpolar segment in the modifying agent, the breakdown property of the modified oils gets more enhancements.

Abstract: Films of hexanoyl chitosan-based polymer electrolytes were prepared using solution casting technique. The interactions between hexanoyl chitosan-lithium perchlorate (LiClO₄) and dimethyl carbonate (DMC)-lithium perchlorate (LiClO₄) were investigated using Fourier transform infrared spectroscopy (FTIR). The FTIR results showed that there is a possible complexation between the electron donor of hexanoyl chitosan and DMC with lithium salt due to the shifting in the wavenumber and changes in the intensity of the infrared bands. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolyte. The ionic conductivity was increased with addition of filler TiO₂ and plasticizer DMC to the electrolyte system.

Abstract: Glass-ceramic materials of the Li₂O-ZnO-SiO₂ system, with various amounts of TiO₂ added, have been prepared. The appropriate heat treatment temperatures were selected according to the information provided by the differential thermal analysis (DTA). X-ray diffraction (XRD) analysis demonstrated that in the LZS glass-ceramics system, the main phases are Li₂ZnSiO₄, cristobalite, tridymite and quartz. The scanning electron microscopy (SEM) revealed that crystals appear as lamellar and spherical particles in the glass-ceramics samples. In addition, the average coefficient of the thermal expansion (CTE) values first decreased, then increased and finally tended to flatten. When the content of TiO₂ increased to 6%, the CTE value decreased to 9.15×10^-6/K, reached the lowest value. When the content of TiO₂ increased to 10%, the CTE value reached highest value 13.90×10^-6/K.