Semiconductor mediated photocatalysed degradation of an anthraquinone dye, Remazol Brilliant Blue R under sunlight and artificial light source

Abstract

Semiconductor mediated photocatalysed degradation of an anthraquinone dye Remazol Brilliant Blue R under sunlight and artificial light source has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in absorption intensity as a function of irradiation time under a variety of conditions. The degradation kinetics were studied under different conditions such as pH, catalyst concentration, substrate concentration, different types of TiO 2 and in the presence of electron acceptors such as hydrogen peroxide (H 2O 2), potassium bromate (KBrO 3) and ammonium persulphate (NH 4) 2S 2O 8 besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient under UV light, whereas Hombikat UV100 was better under sunlight as compared with other photocatalysts. The degradation products were analysed by GC–MS technique and probable pathways for the formation of products are proposed.