Abstract

GIULIANTE, Adriana et al. Physico-chemical properties of La/TiO₂ systems employed for 2-nitrophenol photodegradation using visible ligth from a solar simulator. Rev. Fac. Ing. UCV [online]. 2011, vol.26, n.3, pp.147-154. ISSN 0798-4065.

A series of La/TiO₂ solids were prepared using a conventional impregnation method. The samples were characterized by X-ray diffraction, nitrogen adsorption; point zero charge, FTIR monitoring adsorption of pyridine, and X-ray photoelectron spectroscopy (XPS). Characterization showed that the incorporation of 1%wt. of lanthanum in the oxidized phase partially promotes the anatase-rutile phase transformation under calcination at 500ºC. Also, the presence of this species lead the development of Brönsted surface acid sites and increase the zero point charge, which is desirable for the adsorption of certain species. Furthermore, the catalytic activity of the samples was tested in the photodegradation of 2-nitrophenol in aqueous solution, obtaining an increased activity for doped solids. The major intermediates identified by means of HPLC were cathecol and trihydroxibenzene. On the other hand, for the 1%La doped solid was also identified 2-aminophenol, standing a possible reductive way in the process.

Keywords : TiO₂; Anatase; Lanthanum; Photocatalysis; 2-nitrophenol.