Homogenous photocatalytic degradation of a disperse dye and its dye bath analogue by silicadodecatungstic acid

Arslan-Alaton I.

DYES AND PIGMENTS, vol.60, no.2, pp.167-176, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 60 Issue: 2
  • Publication Date: 2004
  • Doi Number: 10.1016/j.dyepig.2003.07.004
  • Journal Name: DYES AND PIGMENTS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.167-176
  • Istanbul Technical University Affiliated: No


A new method for disperse dye decolourization using the photochemically active silicadodecatungstic acid (H4SiW12O40) + isopropanol (electron donor) redox system has been described. Results of a series of control experiments have indicated that the one-electron reduced form of the silicadodecatungstic acid, SiW12O405-, was responsible for reductive cleavage of disperse dye as evidenced by photochemical heteropoly blue generation upon H4SiW12O40 + isopropanol UV-illumination. A threshold (0.09 mM) and an optimum (0.5 mM) heteropoly acid dose existed for minimum and maximum decolourization rates, respectively. It was also evident that decolourization kinetics were first-order with respect to dye concentration for concentrations up to 75 mg/l, and the photochemical degradation rate became UV-light penetration limited (zero order) above 100 mg/l dye concentration. (C) 2003 Elsevier Ltd. All rights reserved.