The interaction of chromium oxide with different titania-silica supports has been examined. The oxide supports investigated consisted of SiO,, TiO, , physical mixtures of TiO, and SiO,, a surface titania overlayer on SiO, (10% of theoretical monolayer) and a surface silica overlayer on TiO, (80% of theoretical monolayer). The supported chromium oxide catalysts were structurally characterized wi...

Three-dimensional microscale assemblies of fluorine-doped titania nanoparticles were synthesized from silica-based diatom microshells (frustules) via a shape-preserving reactive conversion process (as per the method of Unocic et al.). The nanostructured F-doped titania frustules were found to induce rapid hydrolysis of the organophosphorous esters, methyl paraoxon, and methyl parathion (insecti...

the synthesis of titania via sol-gel method has been widely studied. in the present work, titania was deposited onto a titanium substrate via sol-gel method. different processing parameters such as the repetition number of dipping/heat treatment process and dipping time have been studied to obtain the homogenous titania coating. phase and microstructural evaluation of the powder and coating sam...

The lateral distribution and coverage of Ru-based dye molecules, which are used for dye-sensitized solar cells (DSCs), were directly examined on a titania surface using high-resolution scanning transmission electron microscopy (STEM). The clean surface of a free-standing titania nanosheet was first confirmed with atomic resolution, and then, the nanosheet was used as a substrate. A single dye m...

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...

Cation exchange properties of tetratitanic acid with interlayer protons were measured and compared to those of titania with surface hydroxyl protons using the Frumkin equation. Tetratitanic acid showed larger ion-exchange capacity and much higher activity than titania. The characteristics of exchangeable protons and intercalated cations are discussed to explain the different ion-exchange proper...

The objective of the work was to prepare and characterize titania sol-gel coatings on non-porous titanium and newly developed titanium alloys. Basic titania sol contained two forms of silver. Titania sol without silver was used as a reference sample. Coatings were prepared by dip-coating technique during stirring and fired. Coatings after firing were characterized by scanning electron microscop...

Titania nanosheets are two-dimensional single crystallites of titanium oxide with a thickness of one titanium or two oxygen atoms, and they show attractive material properties, such as photocatalytic reactions. Since a titania (Ti₀.₈₇O₂) nanosheet is synthesized by the delamination of a parent layered K₀.₈Ti₁.₇₃Li₀.₂₇O₄ crystal using a soft chemical procedure, substantial Ti vacancies are expec...

Photocatalysts are being extensively investigated to convert renewable solar energy into chemical energy but suffer from high costs or low efficiencies. We report on the development of highly visible-light photoactive composites of titania (TiO2) and single-wall carbon nanotubes (SWCNTs) that rapidly photodegrade methylene blue dyes under visible-light illumination in the absence of cocatalysts...

Nanosized sulfated zirconia with Brønsted acidic sites has been prepared by a simple calcination in the absence of any solvent. XRD patterns reveal that the sulfated zirconia mainly consists of tetragonal crystalline zirconia with average size of about 7 nm, which is further confirmed by TEM images. N2 adsorption data show that the nanosized sulfated zirconia has high surface area (165-193 m2/g...