We use density functional theory to examine structure− activity relationships of small vanadia clusters supported on anatase TiO2(001) and rutile TiO2(110) surfaces. A thermodynamic analysis indicates that the vanadia monomer cluster can be stabilized on the anatase TiO2(001) surface in a catalytically relevant oxygen environment. On the other hand, vanadia clusters tend to aggregate into dimer...

In this study, the commercial TiO2 nanopowder and micropowder of anatase phase and rutile phase have been characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD patterns of nano-TiO2 in rutile and anatase phases exhibit broad peaks whereas both phases of micro-TiO2 demonstrate very sharp peaks. TEM images show that the grain size of TiO2 micropowders and TiO2 n...

A facile and efficient approach for the fabrication of mesoporous spherical aggregates of anatase nanocrystals is reported in this paper. Cetyltrimethylammonium bromide was used as the structure-directing agent, and the interaction between cyclohexane microdroplets and the cetyltrimethylammonium bromide self-assemblies led to the assembly of 4-5-nm-sized anatase nanocrystals into spherical aggr...

A series of mixed iron and titanium oxide coprecipitates ranging in composition between 0 < Ti/Ti + Fe < 1 was synthesized and aged under varying conditions of pH, temperature and time in order to establish a working model for pedogenic titanium and titano-ferric oxides. X-ray powder diffraction (XRD), selective chemical dissolution, magnetic susceptibility, charge distribution and electron opt...

T w o crystallographic forms of TiC>2 (rutile and anatase) were subject to a n extended x r a y absorption fine structure study a t the K threshold of t i tanium. D a t a analysis was carried out b y Fourier methods and curve fitting techniques. Using the theoretical phases, T i 0 bond distances of 1.93(1) A were derived both for ruti le and anatase, as compared to the crystallographic values o...

Titania films have been grown on polycrystalline BaTiO3 (BTO) substrates at 7001C by pulsed laser deposition. Electron backscatter diffraction (EBSD) was used to determine grain orientations in the substrate before growth, and the phase and orientation of the supported films after growth. All BaTiO3 grains within 261 of (001) were covered by anatase films with an orientation relationship of (00...

Put your best face forward: The performance of TiO2 anatase crystals in energy and environmental applications is normally correlated with the TiO2 crystal facets exposed, and increasing the percentage of highly reactive surfaces is extremely important. A new gas-phase oxidation process using TiCl4 as precursor now yields anatase TiO2 single crystals with primarily high-index {105} facets, which...

Molecular-dynamics simulations have been carried out to study diffusion of water molecules adsorbed to anatase-(101) and rutile-(110) interfaces at room temperature (300 K). The mean squared displacement (MSD) of the adsorbed water layers were determined to estimate self-diffusivity therein, and the mobility of these various layers was gauged in terms of the “swopping” of water molecules betwee...

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...

Titanium dioxide nanoparticles (TiO2NPs), in the two crystalline forms, rutile and anatase, have been widely used in many industrial fields, especially in cosmetics. Therefore, a lot of details about their safety issues have been discussed by the scientific community. Many studies have led to a general agreement about TiO2NPs toxicity, in particular for anatase form, but no mechanism details ha...