Long-time charge separation in porphyrin/KTa(Zr)O 3 as water splitting photocatalyst

Hidehisa Hagiwara, Takanori Inoue, Shintaro Ida, Tatsumi Ishihara

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21 Citations (Scopus)


Artificial photosynthesis is one of the chemists' dreams and the separation of charges with long lives is fundamental for achieving artificial photosynthesis. In actual photosynthesis, Z-scheme excitation separates electronic charge with high efficiency using solar light. Here we report that photo-excitation in Cr-tetraphenylporphyrin chroride (Cr-TPPCl)/Zr doped KTaO 3 (KTa(Zr)O 3) is analogous to the Z-scheme in photosynthesis, and that we achieve complete charge separation at room temperature. Photovoltaic decay and transient fluorescence spectra measurements showed that the photo-excited charge in KTa(Zr)O 3 transferred to the HOMO of Cr-TPPCl within a few hundred pico-seconds on charge transfer. In contrast, the reduced state of the Cr-TPPCl species that was formed by the electronic injection from KTa(Zr)O 3 was observed for more than 0.5 s at room temperature in the transient decay of the absorption spectra change after the initial excitation of KTa(Zr)O 3. The formed reduced state of Cr-TPPCl was highly stable and was detected by static ESR measurements.

Original languageEnglish
Pages (from-to)18031-18037
Number of pages7
JournalPhysical Chemistry Chemical Physics
Issue number40
Publication statusPublished - Oct 28 2011


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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