Search results for "TITANIUM DIOXIDE"

Synthesis of 9-fluorenone and 6H-benzo[c]chromen-6-one through photocatalytic oxidation of phenanthrene by TiO2 photocatalysis

2014

Emissive titanium dioxide nanoparticles synthesized py pulsed laser ablation in liquid phase

2013

The remarkable applications of TiO2 nanomaterials, including, e.g. photocatalysis and dye-sensitized solar cells, have inspired in the last two decades an extensive amount of research aimed at understanding the properties of these materials. Photoluminescence is scarcely used to probe the electronic properties of TiO2, because neither bulk or nanosized TiO2 commonly display room-temperature emission. In particular, the fundamental luminescence due to the recombination of the self-trapped exciton in anatase TiO2 is typically observed only at low temperatures. We report the synthesis of luminescent titanium dioxide nanoparticles (NPs) by pulsed laser ablation of titanium in aqueous solution. …

Highly active photocatalytic TiO2 powdwers obtained by thermohydrolysis of TiCl4 in water

2009

Highly active photocatalytic TiO2 samples were synthesized by thermohydrolysis of TiCl4 in water at 100 °C. Rutile, binary mixtures of anatase and rutile or anatase and brookite, or ternary mixtures of anatase, brookite and rutile were obtained depending on the TiCl4/H2O ratio. Rietveld refinements were employed to evaluate the crystalline phases and composition of the mixtures. The effect of the aging time on the phase composition was also studied. The band gap values of the samples were obtained by the diffuse reflectance spectra. The position of the flat band potentials of anatase, brookite and rutile was determined measuring the photovoltage as a function of the suspension pH. From thes…

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…

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

Photodegradation of pharmaceutical drugs in aqueous TiO2 suspensions: mechanism and kinetics

2007

WOS: 000251165800003

Selectivity of hydroxyl radical in the partial oxidation of aromatic compounds in heterogeneous photocatalysis

2007

Abstract The photocatalytic oxidation of different benzene derivatives has been investigated in order to understand how the substituent group affects the selectivity to hydroxylated compounds. Experimental runs were performed by using TiO2 (Merck) aqueous suspensions at natural pH irradiated by near-UV light. The organic molecules used as substrate contained an electron withdrawing group (EWG) (nitrobenzene, cyanobenzene, benzoic acid, 1-phenylethanone), an electron donor one (EDG) (phenol, phenylamine, N-phenylacetamide) or both an EWG and an EDG (4-chlorophenol). The results clearly indicated that the primary photocatalytic oxidation of aromatic compounds containing an EDG gives rise main…

Solar Eneergy Conversion to Chemical Photocatalytic Selective Oxidation of 5-(Hydroxymethyl)-2-furaldehyde to 2,5-furandicarbaldehyde in Water by Usi…

2013

Photocatalytic degradation of 4-nitrophenol in a continuous reactor containing titanium dioxide supported on glass beads

2008

WOS: 000258975200009

Surface preparation influence on the initial stages of MOCVD growth of TiO2 thin films

2006

In situ chemical surface analyses using X-ray photoelectron spectroscopy (XPS), completed by ex situ atomic force microscopy (AFM) analyses, were performed in order to compare the initial stages of MOCVD growth of TiO 2 thin films on two different surface types. The first type was a silicon native oxide free hydrogen terminated surface and the second one was a silicon dioxide surface corresponding to a thin layer of 3.5 nm thick in situ thermally grown on silicon substrate. Si(100) was used as substrate, and the growths of TiO 2 thin films were achieved with titanium tetraisopropoxide (TTIP) as precursor under a temperature of 675 °C, a pressure of 0.3 Pa and a deposition time of 1 h. Whate…