Oxidative degradation of organic pollutants utilizing molecular oxygen and visible light over a supported catalyst of Fe(bpy)_3~(2+) in water

摘要

This article explores a supported catalyst of Fe(bpy)_3~(2+) on a cationic exchange resin (Amberlite IRA 200) as a photocatalyst for the degradation of organic pollutants by activating molecular oxygen under visible irradiation (lambda>420nm) in water.Different from Fe(bpy)_3~92+) which is not photoactive in solution,the supported catalyst exhibits a very efficient photoactivity for the degradation of N,N-dimethylaniline and the cationic dyes of Rhodamine B (RhB) and Malachite Green (MG) in an aerated aqueous medium.TOC removal yield was 75,60 and 58%,respectively,after 700min of visible light irradiation.The photocatalytic activity of this supported Fe(bpy)_3~(2+0 remained unchanged after 22 cycles of over 100h.The photocatalyst was characterized by UV-Vis diffuse reflectance,and X-ray photoelectron spectroscopies (XPS).EPR studies suggest that the active superoxide species {Fe(bpy)_3~(3+)O_2~(·-)} are involved in the light-activated reaction.A reaction mechanism is proposed in the text.