UV-A Activated ZnO Mediated Photocatalytic Decolorization of Nigrosine (Acid Black 2) Dye in Aqueous Solution

Abstract

The present study deals with studied the essential requirements for photo-decoulorization of nigrosine dye with suspension solution of photocatalyst (ZnO), under 250 Watt UV-A light (Io = 1.47 10-7 ensien s-1). A kinetics study of photo-decolourization for this dye was obeyed to pseudo-first order. The best initial pH of decolorization at 25 mg/L of dye solution with 300 mg of ZnO was given a fast reaction at 8.17. The calculated activation energy for this photoreaction was found to be 31.549 kJ·mol-1. Thermodynamically, the reaction is exothermic and spontaneously. The efficiency of decolorizatio E% was 97.077 at 15 min that decreased with addition oxidant reagents such as H2O2, Fe2+ and mixture from them.