Direct evidence of clay-mediated charge transfer

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Abstract

The charge transfer (CT) from montmorillonite K10 (iron-containing clay) was studied by monitoring the reaction of halides (Cl-, Br-, and I-) with the intercalated photosensitizer, 10-methylacridinium (AcH+). The electrodes, which were fabricated by the AcH+-intercalated clays (denoted clay/AcH+), showed no current responses to bromide and chloride. However, there was a significant current response corresponding to the reduction of iodine and this response was enhanced by light irradiation. These differences in the electrochemical behavior suggested the electron transfer on the clay/AcH+ surface was regulated by the electrochemically active iron species in the clay. The lifetime of AcH+ is ca. 36 ns, whereas for AcH+(clay), it is as fast as the instrumental response (<10 ns), indicating the clay can efficiently quench the excited acridinium, AcH+*. Moreover, a long-lived species, attributed to I2-., was recorded in KI solutions (pH 4) containing either AcH+ or clay/AcH+. In contrast, the transient species, presumed to be Br2-., was only observed in the solutions containing free AcH+. Both electrochemical and laser spectroscopic results indicated that the electron transfer between AcH+* and I- is mediated by the iron species in montmorillonite K10.

Original languageEnglish
Pages (from-to)10386-10389
Number of pages4
JournalJournal of Physical Chemistry B
Volume101
Issue number49
Publication statusPublished - 1997 Dec 4

Fingerprint

clays
Charge transfer
Clay
charge transfer
Bentonite
Iron
montmorillonite
Clay minerals
iron
electron transfer
Electrons
Photosensitizing Agents
Photosensitizers
clay
Iodine
Bromides
iodine
halides
Chlorides
bromides

ASJC Scopus subject areas

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

Cite this

Direct evidence of clay-mediated charge transfer. / Teng, Ya Wen; Chang, I-Jy; Wang, Chong Mou.

In: Journal of Physical Chemistry B, Vol. 101, No. 49, 04.12.1997, p. 10386-10389.

Research output: Contribution to journalArticle

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