Síntese e Caracterização de Compósitos Caulinita-titânio e Aplicação frente à fotodegradação de Corantes de Uso Industrial

Abstract

A purified natural kaolinite was functionalized with titanium (IV) isoproxide via the hydrolytic sol-gel route, later dry in muffle the 100°C and thermally treated at temperatures 400, 700 and 1000 °C for 24 hours and remained without heat treatment. The obtained composites were used on photodegradation of dye methylene blue and Orange II using ultraviolet radiation (λ365nm, 30W). The composites colours degraded efficiently almost entirely after 60 minutes, except the material without heat treatment. The best results were obtained by solid Treaty to 400 ºC that degraded Orange 100 II and methylene blue. Comparative studies with titanium oxide commercial P25 from Degussa were tested and the results reveal lower yields than our systems (45% AM and 15% AL II, 1 h)., taking into account the great concentration between 10 and 25mgL, time of contact of 60 minutes, photocatalyst mass between 50 and 100 mg and pH above 7. The photocatalytic activity of composites is linked primarily to funcionalization in an array because the kaolinite promotes the dispersion of TiO2 on the surface of the material, allowing a greater contact area and thus a greater degradation of dyes. This effect has been confirmed from the comparison of the results of composites with the isolated components (kaolinite and TiO2) material with higher photocatalytic activity was the Ka-TiO2, because after heat treatment there was the obtaining of anatase (Titanium more reactive phase) on the surface of the lamellar material.