Visible light photocatalytic degradation of methyl orange in aqueous suspension by using nanocrystalline TiO2 impregnated with metal-free phthalocyanine pigment

Department of Chemistry, Amirkabir University of Technology, Tehran, Iran

Department of Nanomaterials and Nanotechnology, Institute for Color Science and Technology, Tehran, Iran

E-mail : gharagozlou@icrc.ac.ir    Fa.x : 98-21-22947537

Department of Polymer and Color Engineering, Amirkabir University of Technology, Tehran, Iran

Department of Organic Colorants, Institute for Color Science and Technology, Tehran, Iran

Manuscript received online 23 April 2012, revised 18 June 2012, accepted 19 June 2012

In this paper, the visible light photocatalytic activity of nanocrystalline TiO₂ impregnated with metal-free phthalocyanine pigment (Pc) in aqueous suspension for methyl orange photodegradation has been investigated. For the preparation of the TiO₂ impregnated with phthalocyanine, TiO₂/(Pc), first TiO₂ nanoparticles was prepared by the solgel method and calcined at 400 °C. Then nanocrystalline TiO₂/(Pc) was synthesized via the chemical precipitation method and characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), Fourier transformed infrared (FTIR) and transmission electron microscopy (TEM) techniques. Results revealed that the nanocrystalline TiO₂/(Pc) possesses the anatase structure with the average particle size of about 20-25 nm. The absorption edge of the synthesized TiO₂/ (Pc) has been shifted significantly into the visible region. Our results revealed the photocatalytic activity of TiO₂/(Pc) increased efficiently than TiO₂ nanoparticles under the visible light. Therefore, synthesized nanocrystalline TiO₂/(Pc) is a suitable photocatalyst for use under visible light which make the applicability of TiO₂ photocatalysis even more versatile.