Oxyanion adsorption and competition at a gold electrode.

Journal Article · Tue Oct 31 04:00:00 EST 2000 · Electrochim. Acta

DOI:https://doi.org/10.1016/S0013-4686(00)00516-8· OSTI ID:942655

Melendres, C A; Hahn, F; Bowmaker, G A

Synchrotron Far Infrared Reflectance Spectroscopy (SFIRS) has been used to study the adsorption of oxyanions at a gold thin-film electrode. Surface-adsorbate vibrational frequencies of 240 and 255 cm{sup -1} have been measured 'in-situ' in acid solutions of 0.5 M HClO{sub 4} containing 0.05 M Na{sub 2}SO{sub 4}, and Na{sub 3}PO{sub 4}, respectively. It was observed that in the presence of Br{sup -}, competitive adsorption occurs such that phosphate is displaced from the electrode surface and the current-potential behavior of the electrode is determined by the more strongly adsorbed Br{sup -} anion. In 0.1 M NaClO{sub 4} at neutral pH, no interaction between the oxyanions and the gold surface could be observed and the intensity of Au-Cl{sup -} vibration was about 5 times weaker than in acid. Adsorption of OH was found to be the dominant interaction, inhibiting sulfate adsorption, in 0.05 M Na{sub 2}SO{sub 4}+0.1 M NaClO{sub 4} solution. The latter finding is similar to results obtained by others on the inhibition of sulfate adsorption on Ag by OH{sup -}.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE; NATO
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 942655
• Report Number(s): ANL/CMT/JA-33515
• Journal Information: Electrochim. Acta, Journal Name: Electrochim. Acta Journal Issue: 1 ; Oct 31, 2000 Vol. 46; ISSN 0013-4686; ISSN ELCAAV
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADSORPTION
BROMIDES
CHLORIDES
ELECTRODES
GOLD
HYDROXIDES
INHIBITION
INTERACTIONS
SPECTROSCOPY
SULFATES
THIN FILMS
VIBRATIONAL STATES