Influence of surface properties of activated carbon on photocatalytic activity of TiO2 in 4-chlorophenol degradation.

Abstract

This work shows the influence of specific surface area (BET) and surface pH of different activated carbons on the photocatalytic activity of UV-irradiated TiO2 in the 4-chlorophenol (4CP) photodegradation. Carbons were prepared from sawdust of Tabebuia Pentaphyla wood by physical activation with CO2 and by pyrolysis under N2 flow at tempera- tures from 450 up to 1000oC during 1h Chemical activation was also performed by the impregnation of precursor with ZnCl2, H3PO4 and KOH at different concentrations, followed by activation under N2 flow at 450oC by 1h. Comparison of apparent first-order rate constants between TiO2 against TiO2-AC indicate that TiO2 photoactivity is enhanced or inhibited as a function of AC properties and correlations with surface area and pHPZC were found suggesting that surface pH of car- bons is the most important parameter that influences TiO2 activity in the 4CP photodegradation.