Light-induced electron transer and photoelectrocatalysis of chlorine evolution at FeS2 electrodes

A. Ennaoui, H. Tributsch

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35 Citations (Scopus)

Abstract

Photo-induced electron transfer to FeS2 (Eg = 0.9 eV) (which can be stabilized efficiently by iodide against corrosion at high photocurrent densities (1-2 A cm-2)) was studied using rotating ring disc techniques. With decreasing efficiency I-1, Br- and Cl- compete with water and OH- ions which form photocorrosion products (iron hydroxide, sulfate). I- is very effective in stabilizing n-FeS2 against corrosion even at high photocurrent densities (100% at 1-2 A cm-2). The production efficiency for liberating chlorine (from a 3 M KCl solution at pH 0) is still 73%. Remarkably the electron transfer from Fe2+ and Mn2+ is more than one order of magnitude less efficient, suggesting that specific surface interaction between negative electron donors and iron d-states is involved. Evidently photo-induced electron transfer via a complex formation between surface transition metals and electron donating ligands has a clear advantage over the outer sphere electron transfer mechanism.

Original languageEnglish
Pages (from-to)185-195
Number of pages11
JournalJournal of Electroanalytical Chemistry
Volume204
Issue number1-2
DOIs
Publication statusPublished - 10 Jun 1986
Externally publishedYes

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ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Analytical Chemistry
  • Electrochemistry

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