Electrochemistry of iron oxides: an in-situ Mössbauer study

C. FIERRO; R. E. CARBONIO; D. SCHERSON; E. YEAGER

AMER CHEMICAL SOC

Lugar: Washington; Año: 1987 vol. 91 p. 6579 - 6579

p style="TEXT-ALIGN: justify; LINE-HEIGHT: normal; MARGIN: 0cm 0cm 0pt; TEXT-AUTOSPACE: ; mso-layout-grid-align: none" class="MsoNormal">The electrochemical properties of Fe(OH)2 dispersed on high-area carbon in strongly alkaline media have been studied in situ by Mossbauer spectroscopy. The oxidation of this material was found to yield either an ensemble of small magnetite particles of different sizes or a mixture of superparamagnetic and bulklike magnetite crystals depending on whether the process was carried out by stepping or sweeping the potential to -0.3 V vs Hg/HgO,OH-, respectively. This provides clear evidence that the morphological characteristics of the resulting material are determined by the rate at which the oxidation reaction is performed. Further cathodic polarization to -1.2 V gave rise to the ir