Resumo

CASTRO LOPEZ, Camilo Andrés; REYES GOMEZ, Sonia Esperanza; CENTENO HURTADO, Aristóbulo  e  GIRALDO DUARTE, Sonia Azucena. Effect of the synthesis variables of TiO₂ on the photocatalytic activity towards the degradation of water pollutants. Rev.fac.ing.univ. Antioquia [online]. 2011, n.57, pp.49-56. ISSN 0120-6230.

In this work, TiO₂ photocatalysts were synthesized using a conventional sol-gel and hydrothermal synthesis methods with steam pressure treatment. Photocatalysts were characterized by X-ray diffraction (XRD), diffuse reflectance spectra (DRS) and N₂ adsorption-desorption. The photoactivity of the samples was analyzed towards the photooxidation of the azo dye Orange II (Or-II) and phenol using different illumination set-ups to compare the activity features of photocatalysts. The effect of the synthesis variables such as the synthesis route, water/alcoxide and alcohol/alcoxide ratios, as well as the alcohol type was analyzed. TiO₂ photocatalysts obtained by hydrothermal synthesis have a better photoactivity than the particles synthesized by the chosen sol-gel route, reaching the Or-II degradation photoactivity of the commercial TiO₂ P25. On the other hand, the water/alcoxide ratio and alcohol type have a marked effect on the photoactivity of the hydrothermal synthesized TiO₂, whereas the alcohol/alcoxide ratio does not have a relevant effect on the Or-II degradation photoactivity.

Palavras-chave : TiO₂; photocatalytic oxidation; sol-gel; hydrothermal synthesis; orange II.

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