Study of special cases where the enhanced photocatalytic activities of Pt/TiO2 vanish under low light intensity

Hyunwoong Park, Jaesang Lee, Wonyong Choi

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Surface platinized TiO2 (Pt/TiO2) has been widely used and investigated but their properties are yet to be understood fully. Although it is known that the Pt effects depend on many experimental parameters and the kind of substrates, this study newly finds that the Pt effects could be also influenced by the light intensity. As for the photocatalytic degradation of trichloroethylene (TCE), the Pt effect was positive at high light intensity but was negative at low light intensity. A similar behavior was also observed in the photocurrent collection in the Pt/TiO2 suspension with polyoxometalate (POM: PW12O40 3-) used as an electron shuttle. The photocurrent collection in the Pt/TiO2 suspension was less efficient than in TiO2 suspension when the light intensity was low. Such abnormal light intensity-dependent behaviors were not observed in the photocatalytic degradation of dichloroacetate on Pt/TiO 2 and the Fe3+-mediated photocurrent collection in the Pt/TiO2 suspension. It is proposed that the photochemical interactions between the Pt surface and reactive intermediates (TCE radical anions and reduced POM anions) induce a null reaction favorably at low light intensity condition.

Original languageEnglish
Pages (from-to)259-265
Number of pages7
JournalCatalysis Today
Volume111
Issue number3-4
DOIs
Publication statusPublished - 2006 Feb 15
Externally publishedYes

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Keywords

  • Light intensity effect
  • Photocatalyst
  • Photocurrent
  • Polyoxometalate
  • Surface platinization
  • TiO

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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