In this work we have investigated the role of a porous carbon material used as photocatalyst itself, and catalyst support in a carbon/titania composite towards the photodegradation of phenol, and compared the results to that of bare titanium oxide. The immobilization of titania on an activated carbon provoked an acceleration of the degradation rate under UV irradiation, which is likely attribut...

Organic-inorganic hybrid materials are attractive due to the combination of properties from the two distinct types of materials. In this work, transparent titania-polydimethylsiloxane hybrid materials with up to 15.5 vol. % TiO₂ content were prepared by an in situ non-aqueous method using titanium (IV) isopropoxide and hydroxy-terminated polydimethylsiloxane as precursors. Spectroscopy (Fourier...

Since crystal phase dominantly affects the properties of nanocrystals, phase control is important for the applications. To demonstrate the size dependence in anatase-rutile phase transition of titania, we used quantum-size titania prepared from the restricted number of titanium ions within dendrimer templates for size precision purposes and optical wave guide spectroscopy for the detection. Con...

Parameters and/or processes responsible for the stability of catalyst supports and ceramic membranes are discussed. Two major parameters/processes were identified which are responsible for the stabiliv of sol-gel derived nanostmctured oxides at elevated temperatures. They are metastable-to-stable phase transformation and structure and packing of primary particles within the aggregate. Based on ...

Recyclable aggregates of mesoporous titania with different anatase-rutile ratios have been prepared by thermal treatments of either amorphous or peptized precursors. These last two have been obtained by hydrolysis of either Ti(OC₂H₅)₄ or of Ti(OC₂H₅)₄ in mixture with 5 mol % Zr(OC₃H₇)₄ at room temperature in the presence of NH₄OH as a catalyzing agent. The anatase-rutile ratio, the recyclable a...

Photocatalytic reduction of carbon dioxide has been investigated on three different titania catalysts (two commercial titania, De Gussa P-25 and UV-100 Hombikat and another catalyst prepared by sol-gel method under reverse micelle environment) dispersed in aqueous alkaline medium under irradiation in visible region (300-700 nm) from Hg lamp. The catalysts have been characterized by XRD, diffuse...

The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, prolifera...

BACKGROUND Titania dioxide (TiO(2)) photocatalyst is primarily induced by ultraviolet light irradiation. Visible-light responsive anion-doped TiO(2) photocatalysts contain higher quantum efficiency under sunlight and can be used safely in indoor settings without exposing to biohazardous ultraviolet light. The antibacterial efficiency, however, remains to be further improved. METHODOLOGY/PRINC...

TiO₂ photocatalysis is considered as an alternative to conventional disinfection processes for the inactivation of waterborne microorganisms. The efficiency of photocatalysis is limited by charge carrier recombination rates. When the photocatalyst is immobilized on an electrically conducting support, one may assist charge separation by the application of an external electrical bias. The aim of ...

The formation of a dispersed titanium oxide layer on Cabosil-fumed silica and on nonporous silica spheres was studied by infrared and Raman spectroscopies and by transmission electron microscopy (TEM). The procedure for obtaining the titania coatings involved reacting the silanol groups on the silica surface with titanium alkoxides under a N 2 atmosphere. This self-limiting reaction led to a co...