An-Najah Staff

Widely spread chemically industry produces many types of water pollutants (e.g dyes,  herbicides, pesticides, insecticides, drugs, and others). Most of such pollutants reach our  drinking water resources. Different strategies have been followed to purify contaminated  water, one low-cost technology involves semiconductors as catalysts for photo-degradation  of organic contaminants. TiO2 is widely studied for water treatment. However, the wide  band gab TiO2 limits its use in the UV range, which is less than 4% of our reaching-in  solar spectrum. Therefore, sensitization of TiO2 has been studied in order to activate the  photo-degradation processes by the visible light.  In earlier work we used CdS (~2.3 eV) to sensitize TiO2. The prepared TiO2/CdS catalyst  showed relatively high catalytic efficiency in visible light in photo-degradation of organic  water contaminants (Methyl Orange & Phenazopyridine). During the photo-degradation  process the CdS decomposed producing Cd+2  ions in the treated water.  In this work, a safe, economic, nontoxic natural dye (anthocyanin) is being used to  sensitize TiO2 nano-particles, the produced catalysts TiO2/anth and AC/TiO2/anth were  tested for photo-degradation of both methyl orange and phenazopyridine. Under visible  light, the prepared catalysts showed observable efficiencies. The efficient degradation was  observed in photo-degradation methyl orange using AC/TiO2/anth under acidic condition.  Complete mineralization of contaminants was confirmed by the potential increasing of  menial ions like NO-3 , SO4 -2  and S2O3 -2 . Effect of different reaction parameters, together  with reaction kinetics, will be presented.