Rapid preparation of 伪-FeOOH and 伪-Fe₂O₃ nanostructures by microwave heating and their application in electrochemical sensors

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• 作者：J.Z. Marinho ; R.H.O. Montes ; A.P. de Moura ; E. Longo ; J.A. Varela ; R.A.A. Munoz ; R.C. Lima
• 关键词：A. Oxides ; B. Chemical synthesis ; C. X-ray diffraction ; C. Electron microscopy ; D. Electrochemical properties
• 刊名：Materials Research Bulletin
• 出版年：January, 2014
• 年：2014
• 卷：49
• 期：Complete
• 页码：572-576
• 全文大小：1048 K

文摘

伪-FeOOH (goethite) and 伪-Fe₂O₃ (hematite) nanostructures have been successfully synthesized using the microwave-assisted hydrothermal (MAH) method and by the rapid burning in a microwave oven of the as-prepared goethite, respectively. The orthorhombic 伪-FeOOH to rhombohedral伪-Fe₂O₃ structural transformation was observed by X-ray diffraction (XRD) and Raman spectroscopy results. Plates-like 伪-FeOOH prepared in 2 min and rounded and quasi-octahedral shaped 伪-Fe₂O₃ particles obtained in 10 min were observed using field emission gun scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The use of microwave heating allowed iron oxides to be prepared with shorter reaction times when compared to other synthesis methods. 伪-FeOOH nanoplates were incorporated into graphite-composite electrodes, which presented electrocatalytic properties towards the electrochemical oxidation of ascorbic acid in comparison with unmodified electrodes. This result demonstrates that such 伪-FeOOH nanostructures are very promising chemical modifiers for the development of improved electrochemical sensors.