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
. Effect of different reaction parameters, together
with reaction kinetics, will be presented