Photochemical production of reactive oxygen species by C60 in the aqueous phase during UV irradiation

Jaesang Lee, John D. Fortner, Joseph B. Hughes, Jae Hong Kim

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128 Citations (Scopus)

Abstract

The objective of this study was to investigate photochemical production of singlet oxygen (1O2) and superoxide radical anion (O 2 •-) by C60 in water. It was demonstrated that photoexcited C60 in the aqueous phase efficiently mediated transfer of absorbed energy to oxygen and produced singlet oxygen when associated with surfactant (Triton X100 and Brij 78) or polymer (polyvinylpyrrolidone), which is consistent with previously observed behavior in organic solvents. However, when C60 was present as colloidal aggregate suspension, prepared through solvent exchange or sonication, this intrinsic character was lost. Similarly, C60 associated with surfactant mediated electron transfer from electron donor (triethylamine) to oxygen producing superoxide radical, while C60 aggregates and C 60 associated with polymer did not. These results suggest that the ability of C60 to mediate energy and electron transfer may be affected by the degree of C60 aggregation in the aqueous phase as well as characteristics of associated stabilizing molecules. Dependence of photochemical reactivity of C60 on its dispersion status in the aqueous phase is critical in assessing environmental impact and cytotoxicity of this material, as C60 associated with model natural organic matter was found to exist in aggregate form and did not produce reactive oxygen species under UV irradiation.

Original languageEnglish
Pages (from-to)2529-2535
Number of pages7
JournalEnvironmental Science and Technology
Volume41
Issue number7
DOIs
Publication statusPublished - 2007 Apr 1
Externally publishedYes

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ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Science(all)
  • Environmental Chemistry

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