Visible light active platinum-ion-doped TiO2 photocatalyst

Soonhyun Kim, Seong Ju Hwang, Wonyong Choi

Research output: Contribution to journalArticle

349 Citations (Scopus)

Abstract

Platinum-ion-doped TiO2 (Ption-TiO2) was synthesized by a sol-gel method, and its visible light photocatalytic activities were successfully demonstrated for the oxidative and reductive degradation of chlorinated organic compounds. Ption-TiO2 exhibited a yellow-brown color, and its band gap was lower than that of undoped TiO2 by about 0.2 eV. The flat band potential of Pt ion-TiO2 was positively shifted by 50 mV compared with that of undoped TiO2. X-ray absorption spectroscopy and X-ray photoelectron spectroscopy analyses showed that the Pt ions substituted in the TiO2 lattice were present mainly in the Pt(IV) state with some Pt(II) on the sample surface. Ption-TiO2 exhibited higher photocatalytic activities than undoped TiO2 under UV irradiation as well. The visible light activity of Ption-TiO2 was strongly affected by the calcination temperature and the concentration of Pt ion dopant, which were optimal at 673 K and 0.5 atom %, respectively. Under visible irradiation, Ption-TiO2 degraded dichloroacetate and 4-chlorophenol through an oxidative path and trichloroacetate via a reductive path. The activity of Ption-TiO2 was not reduced when used repeatedly under visible light. However, visible-light-illuminated Ption-TiO2 could not degrade substrates such as tetramethylammonium and trichloroethylene, which are degraded with UV-illuminated TiO2. The characteristics and reactivities of Ption-TiO2 as a new visible light photocatalyst were investigated in various ways and discussed in detail.

Original languageEnglish
Pages (from-to)24260-24267
Number of pages8
JournalJournal of Physical Chemistry B
Volume109
Issue number51
DOIs
Publication statusPublished - 2005 Dec 29

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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