An in situ Raman spectroscopic study of electrochemical processes in mercury–solution interphases

✍ Scribed by Alexandre G. Brolo; Marek Odziemkowski; Donald E. Irish

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 299 KB
• Volume: 29
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199808)29:8<713::aid-jrs296>3.0.co;2-j

✦ Synopsis

Electrochemical processes in the mercury-solution interphase were probed by in situ spectroelectrochemical micro-Raman spectroscopy. This is the Ðrst report of the in situ characterization of electrochemical processes for a pure mercury electrode by Raman spectroscopy. Mercury was oxidized in 0.1 M solution, in the presence and KClO 4 absence of pyridine. Raman spectra, at several applied potentials, of the soluble oxidation products present in the mercury/solution interphase were recorded. The aquated [ mercury(I) ] cation was the only product observed Hg 2 2' for mercury oxidation in the absence of pyridine. This cation was characterized by the Hg-Hg stretch band at ca. 175 cm-1. An precipitate was formed on the electrode surface at very anodic potentials. The oxida-Hg 2 2'-ClO 4 tion of mercury in the presence of pyridine resulted in the formation of soluble mercury(II)-pyridine complexes in the interphase. Characteristic Raman bands of these complexes were observed at ca. 1023 and 1048 cm-1. Solution Raman experiments demonstrated that a mixture of mercury(II)-pyridine complexes [ of general formula where 1 AE n AE 4] was produced in the interphase. 1998 John Wiley & Sons, Ltd. Hg(py) n 2',