Search results for "NATAS"

Computational modeling of single-versus double-anchoring modes in di-branched organic sensitizers on TiO2 surfaces: structural and electronic propert…

2014

We present a first-principles DFT investigation of the adsorption geometry on the anatase (101) surface of a prototypical di-branched organic dye based on the extended tetrathiafulvalene moiety, incorporating two anchoring cyanoacrylic acid units. Reduced model systems with one and two anchoring groups have been initially studied to investigate the vibrational frequencies related to TiO2 dye adsorption. Our calculations confirm that the reduced systems can be used as reliable models to study the anchoring modes and that the conclusions extracted from the reduced systems can be extrapolated to the entire molecule. A series of molecular structures have been investigated to simulate the anchor…

A Thermo-Kinetic Study of Titanium Oxidation Assisted by a Nd-YAG Pulsed Laser

2004

ESR study of photo-oxidation of phenol at low temperature on polycrystalline titanium dioxide

1994

The formation of oxygen radicals on hydrated TiO 2 (anatase) samples irradiated at 77 K in the near-UV region and their interaction with adsorbed phenol molecules have been studied by electron spin resonance. The results indicate that the irradiation determines the generation of O 2 H · and O − radicals which react with adsorbed phenol molecules. Phenol-derived radicals are generated after warming the sample at room temperature. A reaction mechanism is proposed on the basis of the observed species.

Photocatalysis in dimethyl carbonate green solvent: degradation and partial oxidation of phenanthrene on supported TiO2

2014

Dimethyl carbonate (DMC) is here proposed – for the first time – as a green organic solvent for photocatalytic synthesis. In this work, the photocatalytic partial oxidation of phenanthrene in dimethyl carbonate (DMC) by using anatase TiO2 as the photocatalyst is described as paradigmatic example of a green synthetic process starting from polycyclic aromatic hydrocarbons (PAHs). For comparison, the same reaction carried out also in ethanol, 1-propanol or 2-propanol is reported. The use of DMC as the solvent allowed us to achieve 19% and 23% selectivity towards 9-fluorenone and 6H-benzo[c]chromen- 6-one, respectively. The proposed approach may represent both a new green synthetic process and …

Graphite-supported TiO2 for 4-nitrophenol degradation in a photoelectrocatalytic reactor

2009

WOS: 000274769500044

Nanostructured anatase TiO2 densified at high pressure as advanced visible light photocatalysts

2015

This study reports on characterization and photoactivity of nanostructured TiO2 samples, which have been permanently densified under high pressures, up to 2.1 GPa. Commercial Mirkat 211 anatase has been used as a benchmark sample, in order to investigate the effect of unidirectional high pressure on structural, optical and photocatalytic properties of TiO2. Vibrational Raman spectroscopy shows that the treatment does not cause transitions among the different crystalline phases of titanium dioxide. UV-vis diffuse reflectance spectra reveal that increasing pressure gives rise to a shift of the absorption onset towards higher wavelength enhancing the photoactivity under visible radiation. Samp…

N-Doped Anatase/Rutile Photocatalysts for the Synthesis of Aromatic Aldehydes Under Ultraviolet and Solar Irradiation

2015

N-doped anatase/rutile photocatalysts were prepared by a sol-gel method, using TiCl4 as TiO2 precursor and urea as N-dopant source. The catalysts required a thermal treatment at temperature higher than 300 degrees C to achieve actual nitrogen doping; this treatment also allowed obtaining crystalline and hydrophobic samples. Moreover, nitrogen doping modified the surface of samples by increasing the anatase to rutile phase ratio and hydrophilicity. The catalysts were characterized by BET specific surface area, XRD, ESEM, TGA, FT-IR, DRS and XPS measurements, with particular attention to the assessment of the N-doping effect. It was found that XPS analysis should be used together with DRS and…

Partial photocatalytic oxidation of glycerol in TiO2 water suspensions

2010

2nd European Conference on Environmental Applications of Advanced Oxidation Processes -- SEP 09-11, 2009 -- Nicosia, CYPRUS

2D Slab Models of Nanotubes Based on Tetragonal TiO2 Structures: Validation over a Diameter Range

2021

This research was funded by the M-ERA.NET project ?Multiscale computer modelling, synthesis and rational design of photo(electro)catalysts for efficient visible-light-driven seawater splitting? (CatWatSplit). Institute of Solid State Physics, University of Latvia as the Center of Excel-lence has received funding from the European Union?s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.

Pyrolysis study of sol-gel derived TiO2powders

2004

An amorphous TiO2 gel was obtained by hydrolysing titanium(IV) isopropoxide with a stoichiometric amount of water using SnCl2 as catalyst. In these operative conditions, a TiO2 gel matrix containing a lower fraction of organic residual was obtained with respect to samples prepared by previously modifying the titanium alkoxide precursor with chelating ligands. Dried gel powders were characterized by N2 adsorption analyses, FT-IR and XRD measurements. Thermogravimetric (TG) and differential thermal analysis (DTA) coupled with mass spectrometric (MS) and gas chromatographic (GC) measurements were performed in order to identify the organic products released from TiO2 gel pyrolysis. The Tg-MS se…