Resumen

GORDILLO-DELGADO, F.; VILLA-GOMEZ, K.  y  MARIN, E. Shifting to the red the absorption edge in TiO₂ films: a photoacoustic study. Superf. vacío [online]. 2011, vol.24, n.1, pp.20-23. ISSN 1665-3521.

When Titanium dioxide in contact with a polluted water sample is irradiated with ultraviolet light, electron-hole pairs can be generated, which can react with oxygen and water producing free radicals that can degrade the pollutants, changing them into harmless compounds for the environment. The ultraviolet component of the solar radiation is around 7%. Therefore, it is convenient to modify the TiO₂ films crystalline structure for obtaining photocatalytical processes with visible light. In this work we report on the growth of TiO₂ thin films by the Sol-gel technique considering the incorporation of AgNO₃ in the initial solution containing the precursor. The concentration of the AgNO₃ saline solution was changed between 5 and 30% to control the grain size of the grown TiO₂ nanocrystals, impregnating 6 layers over glass slide substrates and using a sintering temperature of 600 °C. The obtained films were characterized structurally by means of X-ray diffraction. The shift in the forbidden energy bandwidth value to the red part of the optical absorption spectrum was evidenced by Photoacoustic Spectroscopy. The photocatalytic activity was tested on a solution of methylene blue using also the Photoacoustic technique.

Palabras llave : Titanium dioxide; Thin films; Sol-gel; Photocatalysis; Photoacoustic.

        · texto en Inglés     · Inglés ( pdf )