CORRELATIONS BETWEEN ACTIVATED CARBON PROPERTIES AND PHOTOCATALYTIC ACTIVITY OF TiO_2 IN 4-CHLOROPHENOL DEGRADATION

摘要

This work shows correlations between some physicochemical properties of activated carbon (AC) with photocatalytic activity of TiO_2 in 4-chlorophenol (4CP) photodegradation under UV-irradiation. Carbons were prepared from Tabebuia Pentaphyla wood by physical and chemical activation. Results indicate that photoactivity of TiO_2 is clearly influence by AC characteristics. Kinetic results of 4CP photodegradation indicate that most of TiO_2-AC photocatalysts showed a synergistic effect between both solids estimated from the apparent first-order constant rate with a maximum of photoactivity of about 3 times higher than that detected on TiO_2 alone. Not only higher surface areas but also an increase in electron density of AC enhanced Titania's photoactivity for 4-chlorophenol degradation. A scheme for the interaction between both solids is proposed and it permits to explain the improved photoactivity of TiO_2 in presence of AC.