A STUDY OF THE DISCHARGE PROCESS OF MANGANESE OXIDE IN BORATE SOLUTION USING IN SI TU TECHNIQUES

B. A. LÓPEZ DE MLSHIMA; TOSHIAKI OHTSUKA; NORIO SATOF

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1993 vol. 38 p. 341 - 347

0013-4686

The change of electrodeposited manganese oxide on gold during the reduction process wasinvestigated in borate solution at pH 9.2, using in situ optical techniques. Raman spectroscopy (RS) showed five bands of manganeso dioxide at 410, 480, 520, 580 and 640 cm"1, which decreased and disappeared during the cathodic discharge process. These changes occurred reversibly during the reductionoxidation cycle. The band at 580 cm"1 can be assigned to the Mn—O stretching because of the correlation found between the XPS analyses and the Raman spectroscopy. In situ Raman spectra of thermal manganese oxide were also performed, and showed the same five Raman bands at 415, 485, 515, 585 and 635 cm"1. Electrochemically modulated infrared spectroscopy (EMIRS) is associated with the appearance of a O—H stretching band. The changes of RS, EMIRS and XPS reveal the proton-electron injection for the reduction reaction of electrolytic MnO2.