Quantum yield study of the photodegradation of hydrophobic dyes in the presence of acetone sensitizer

S. M. Tsui, Wei Chu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

31 Citations (Scopus)

Abstract

The photodegradation of hydrophobic disperse dyes with different chromophores in the presence of acetone (ACE) was investigated. In this study, the photodecay of dyes was carried out in the Rayonet™ RPR-200 merry-go-round photoreactor, with 253.7 nm monochromatic ultraviolet (UV) lamps. A typical azo disperse dye (CI disperse yellow 7-DY7) and an anthraquinone disperse dye (CI disperse orange - DO11) were used as the probe compounds. The results demonstrate that the addition of acetone increases the solubility of hydrophobic disperse dyes and enhances the photosensitization reaction simultaneously. More than ten times of quantum yield enhancement is observed in the presence of ACE photosensitizer than in water alone. The photodegradation of DY7 and DO11 is dominated by photoreduction, which follows pseudo first-order decay, and the rate constants strongly depend on the solvent system (i.e., ACE/H2O ratios) and the initial pH levels. The decay quantum yields of dyes are normally observed with the increase of the ACE/H2O ratio. The optimum quantum yields of DY7 and DO11 were determined at 0.5 (v/v) and 0.25 (v/v), respectively, in alkaline conditions. A further increase in the ACE/H2O ratio reduces the quantum yields, possibly due to light attenuation by excess acetone.
Original languageEnglish
Pages (from-to)17-22
Number of pages6
JournalChemosphere
Volume44
Issue number1
DOIs
Publication statusPublished - 23 Jun 2001

Keywords

  • Acetone
  • Anthraquinone
  • Azo
  • Disperse dye
  • Quantum yield
  • Sensitizer
  • Ultraviolet

ASJC Scopus subject areas

  • Environmental Chemistry
  • Chemistry(all)

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