Mineralization of Azo Dye Using Combined Photo-Fenton and Photocatalytic Processes under Visible Light

Abstract

Visible-light-assisted photodegradation of an azo dye, Reactive Red 180 (RR180), in the presence of nitrogen-doped TiO 2 (N-TiO 2 ) has been studied. The photodegradation of RR180 is evaluated through decolorization studies and total organic carbon analysis. The efficacy of hydrogen peroxide (H 2 O 2 ), potassium peroxomonosulfate (oxone or PMS), and potassium peroxodisulfate (PDS) in improving the photodegradation of the dye in the N-TiO 2 -RR180 system is also examined. The effect of combining photo-Fenton-like reaction with N-TiO 2 -mediated photodegradation of RR180 under visible light has been investigated. The photoactivity of N-TiO 2 -RR180-Fe 3+ /Cu 2+ -oxidant systems is compared with the individual techniques of photocatalysis and photo-Fenton-like reactions. The coupled system possesses superior photomineralization ability towards the abatement of RR180.