Nanocrystalline TiO2 powders were synthesized by thermohydrolysis of TiCl4 in HCl or NaCl aqueous solutions. Rutile, mixtures of brookite and rutile or mixtures of anatase, brookite and rutile were obtained depending on the acidity of the medium. Crystalline phases and composition of the mixtures were identified by using XRD analysis. Pure brookite nanoparticles, separated from the mixtures of brookite and rutile by simple peptization with water, were stable against transformation to rutile up to 750°C. The prepared TiO2 powders were characterized by thermal analysis, diffuse reflectance spectroscopy and BET surface area determinations. The band gap of bulky brookite was estimated 3.29 eV. 4-Nitrophenol photodegradation was used to evaluate the photocatalytic activity of the various samples. The highest activity corresponded to the powders consisting of more than one crystalline phase.
DI PAOLA, A., G CUFALO, ADDAMO, M., BELLARDITA, M., CAMPOSTRINI, R., ISCHIA, M., et al. (2008). Photocatalytic activity of nanocrystalline TiO2 (brookite, rutile and brookite-based) powders prepared by thermohydrolysis of TiCl4 in aqueous chloride solutions. COLLOIDS AND SURFACES. A, PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 317, 366-376 [10.1016/j.colsurfa.2007.11.005].
Photocatalytic activity of nanocrystalline TiO2 (brookite, rutile and brookite-based) powders prepared by thermohydrolysis of TiCl4 in aqueous chloride solutions
DI PAOLA, Agatino;ADDAMO, Maurizio;BELLARDITA, Marianna;PALMISANO, Leonardo
2008-01-01
Abstract
Nanocrystalline TiO2 powders were synthesized by thermohydrolysis of TiCl4 in HCl or NaCl aqueous solutions. Rutile, mixtures of brookite and rutile or mixtures of anatase, brookite and rutile were obtained depending on the acidity of the medium. Crystalline phases and composition of the mixtures were identified by using XRD analysis. Pure brookite nanoparticles, separated from the mixtures of brookite and rutile by simple peptization with water, were stable against transformation to rutile up to 750°C. The prepared TiO2 powders were characterized by thermal analysis, diffuse reflectance spectroscopy and BET surface area determinations. The band gap of bulky brookite was estimated 3.29 eV. 4-Nitrophenol photodegradation was used to evaluate the photocatalytic activity of the various samples. The highest activity corresponded to the powders consisting of more than one crystalline phase.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
