Photocatalytic degradation of 4-chlorophenol under visible light by using TiO2 catalysts impregnated with Co(II) and Zn(II) phthalocyanine derivatives

Mahmiani Y., SEVIM A. M. , Gül A.

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, vol.321, pp.24-32, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 321
  • Publication Date: 2016
  • Doi Number: 10.1016/j.jphotochem.2015.12.015
  • Page Numbers: pp.24-32


In order to realize the photocatalytic reactions by visible light more efficiently, the photocatalytic activity of polycrystalline TiO2 samples impregnated with carboxy functionalized Co(II) or Zn(II)-phthalocyanine as heteregoneous photocatalyst has been investigated. For this purpose, metallophthalocyanines(MPc) substituted with mercapto benzoic acid groups on each benzo moiety were incorporated into TiO2 semiconductors to prepare TiO2-MPc composites as heterogeneous catalysts. TiO2 and TiO2-MPc composites were characterized by making use of X-ray diffraction (XRD), infrared spectroscopy (FTIR) and UV-vis diffuse reflectance spectroscopy. The characterization results show that MPcs are anchored on the surface of TiO2 through CO-O-TiO2 bonds. The optimum loading of the dyes on TiO2 were 0.49 mu mol/g TiO2 for ZnPc and 0.56 mu mol/g TiO2 for CoPc, nearly independent of TiO2 used. These novel heterogeneous photocatalysts were used for the degradation of 4-chlorophenol (4-CP) in aqueous media in the presence of visible irradiation monitored by GC-MS spectroscopy. The catalysts revealed enhanced activity in visible region for the degradation of 4-CP when compared with that of pure TiO2, which is attributed to the cooperative function of the two components of the photocatalyst. The amount of remaining 4-chlorophenol residue was determined by using an internal standard (phenol) with gas chromatography-mass spectrometry and during the first 30 minutes 99% degradation of 4-chlorophenol was observed. (C) 2015 Elsevier B.V. All rights reserved.