Visible light-induced photosensitized decomposition of organic pollutants with polymer nanocapsules encapsulating Fe(bpy)32+ complex

Abstract

Cross-linked polymer nanocapsules (PC) encapsulating an iron tris(bipyridine) complex, Fe(bpy)32+@PC, have been synthesized by a ship-in-a-bottle method. This was used as a photosensitizer for the decomposition of organic pollutant in water under visible light irradiation with molecular oxygen. The Fe(bpy)32+@PC promotes efficient decomposition of organic pollutant, whereas noncapsulated Fe(bpy)32+ is inactive. The enhanced sensitization activity of Fe(bpy)32+ within PC is due to the interaction with the PC wall. This lengthens the lifetime of the excited state Fe(bpy)32+ and promotes efficient production of hydroxyl radicals. The sensitization activity of Fe(bpy)32+@PC depends on the thickness of the PC wall. The Fe(bpy)32+@PC with an appropriate PC wall thickness allows accumulation of pollutant within the PC and, hence, promotes efficient decomposition of pollutant.