In this study, the cytotoxicity of two different crystal phases of TiO2 nanoparticles, with surface modification by humic acid (HA), to Escherichia coli, was assessed. The physicochemical properties of TiO2 nanoparticles were thoroughly characterized. Three different initial concentrations, namely 50, 100, and 200 ppm, of HA were used for synthesis of HA coated TiO2 nanoparticles (denoted as A/...

Detailed EPR investigations on as-grown and annealed TiO2 nanoparticles in the anatase and rutile phases were carried out at X-band (9.6 GHz) at 77, 120-300 K and at 236 GHz at 292 K. The analysis of EPR data for as-grown and annealed anatase and rutile samples revealed the presence of several paramagnetic centers: Ti3+, O-, adsorbed oxygen (O2-) and oxygen vacancies. On the other hand, in as-g...

Nanoscale titanium dioxide is an important physical sun-block material and is widely used in sunscreen. In our test, the influences of the particle size and crystal structure on light absorbance were examined. The experiment shows that the absorbance (Abs) of nanoscale titanium dioxide in UV-ray district is much higher than it in visible light district under the same concentration (0.04 g/L). T...

Recent breakthrough of novel hierarchic materials, orchestrated through oriented attachment of crystal subunits, opened questions on what is the mechanism of their self-assembly. Using rutile-type TiO2, synthesized by hydrothermal reaction of Ti(IV)-butoxide in highly acidic aqueous medium, we uncovered the key processes controlling this nonclassical crystallization process. Formation of comple...

sn02 nanowires with diameters of 30 — 200 nm have been synthesized by using carbothermalprocess via a thick film of tin dioxide and carbon powder precursor. the nanowires werecharacterized by x-ray power diffraction (xrd), scanning electron microscopy (sem),transmission electron microscopy (tem) and selected area electron diffraction (saed).the gas sensing characteristic of nanowires toward eth...

We propose a scheme to enhance near-UV band absorption of a rutile TiO(2) nanoparticle by placing Au nanoparticles in its neighborhood. The discrete-dipole approximation method was employed to calculate the absorption spectrum of pure rutile TiO(2) and that of TiO(2) mixed with Au nanoparticles. The results indicate that pure rutile TiO(2) has its maximum absorption located in the deep-UV band....

The symmetric chain Pt-TiO -Pt was studied by means of complex impedance spectroscopy at T = 1273 K for pure and chromium-doped rutile in the partial pressure of oxygen range from 10 to 1 atm. The isothermal variations of electronic conductivity of rutile doped with 1 to 5 % atoms Cr as a function of P were interpreted in terms of point defects by the model of mixed-valence chromium. The compar...

The influence of calcination time on the phase transformation and crystallization kinetics of anodized titania nanotube arrays was studied using in-situ isothermal and non-isothermal synchrotron radiation diffraction from room temperature to 900 °C. Anatase first crystallized at 400 °C, while rutile crystallized at 550 °C. Isothermal heating of the anodized titania nanotubes by an increase in t...

A comparison has been drawn in pure anatase and rutile forms of TiO2 films with their respective nano crystalline forms as photoanodes in dye-sensitized solar cells. All the films have been synthesized by using sol-gel method. Crystalline nature of the films has been investigated by x-ray diffraction (XRD) and morphologies have been studied by scanning electron microscopy (SEM). The short-circu...

Titania films were grown on BaTiO3 (BTO) substrates by pulsed laser deposition to create (001)Anatase||(100)BTO, (100)Rutile||(111)BTO, and (110)Rutile||(110)BTO heterostructures. The photochemical reactivity was evaluated by observing the amount of silver reduced by each film under identical conditions. The thickest films (100 nm) had reactivities that varied with the phase of titania and the ...