Síntesis y caracterización de titania dopada con nitrógeno

ELIANA G. PÉREZ; ANA E. CARDOZO; E.M. FARFÁN TORRES; EDGARDO L. SHAM

Cordoba

Congreso; Congreso internacional de metalurgia y materiales 16 sam conamet; 2016

SAM-CONAMET

In this work nitrogen-doped TiO2 has been prepared. TiO2 was obtained from the hydrolysis of titaniumisopropoxide (IPT), as titanium precursor, using water and cyclohexane as water dispersing agent. IPT andwater volumes were added in stoichiometric ratio. TiO2 was then dispersed in a mixture of urea in analcoholic medium, as nitrogen precursor [1]. After elimination of solvent the material was subjected togrinding treatment. The theoretical molar ratio N/Ti was 1 and the volume ratio C6H12/IPT was 2. Theobtained solid was calcined at two temperatures in static air with high heating rate and residence time ofone hour. The samples were characterized by IR and Raman spectroscopy, specific surface, diffusereflectance, thermogravimetric and thermodifferential analysis and zeta potential. The Raman spectroscopyshows the presence of the three crystalline phases of TiO2, anatase, brookite and rutile. At the highercalcination temperature spectra shows redshift, an increasing of the intensity and a decrease of the width inthe peaks corresponding to anatase crystalline phase [2]. For the two used calcination temperatures solidspresent absorption in the visible and a band gap value of 3.2 eV. When the calcination temperatureincreased the specific surface of solids decreases. The photocatalytic activity of the solids was evaluated intartrazine degradation under visible light, obtaining the best performance for the sample calcined at 400°C.Our results allow saying that this behaviour is due to presence of three crystalline phases that decreases therecombination of photogenerated electrons and holes [3] and the absorption of visible light.