Characterizations of iron-rich clay modified electrodes and their applications in optical recognition

Suh Ching Shyu, Chong Mou Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Optical recognition was studied with modified electrodes based on iron-rich clays. According to energy-dispersive X-ray spectroscopy (EDX), several clay minerals including montmorillonite K10 (mont. K10) contain a lot of iron. Cyclic voltammetry suggested that electrochemically active iron species exist in most iron-rich clays and are likely to reside at different sites. The associated electrochemical activity is strongly pH-dependent and photosensitive. Under UV irradiation (λ ≤ 420 nm), these iron species were activated, and a pronounced photocurrent resulted. When these electrodes were flow-injected with 2-pyridylcarboxylic acids (λab,max = 260 nm), the originally monotonic photocurrent could be modulated into a more recognizable a.c. pattern and the 260 nm optical signal became distinguishable. The photoresponse was highly reproducible, and the response time (t90) was less than 10s.

Original languageEnglish
Pages (from-to)27-33
Number of pages7
JournalJournal of Electroanalytical Chemistry
Issue number1-2
Publication statusPublished - 1997 Dec 20


  • Characterization
  • Iron-rich clay
  • Modified electrodes
  • Optical recognition

ASJC Scopus subject areas

  • Analytical Chemistry
  • General Chemical Engineering
  • Electrochemistry


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