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Title: Rapid preparation of α-FeOOH and α-Fe{sub 2}O{sub 3} nanostructures by microwave heating and their application in electrochemical sensors

Graphical abstract: - Highlights: • Simple microwave method leads to the rapid formation of the goethite and hematite. • Homogenous nucleation and growth of particles are controlled by synthesis time. • Modified electrode with α-FeOOH nanoplates improved the electrochemical response. • The sample is directly heated by microwaves and its crystallization is accelerated. • Fe{sup 3+} nanostructures are promising for development of electrochemical sensors. - Abstract: α-FeOOH (goethite) and α-Fe{sub 2}O{sub 3} (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 α-FeOOH to rhombohedralα-Fe{sub 2}O{sub 3} structural transformation was observed by X-ray diffraction (XRD) and Raman spectroscopy results. Plates-like α-FeOOH prepared in 2 min and rounded and quasi-octahedral shaped α-Fe{sub 2}O{sub 3} 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. α-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 suchmore » α-FeOOH nanostructures are very promising chemical modifiers for the development of improved electrochemical sensors.« less
Authors:
;  [1] ; ; ;  [2] ;  [1] ;  [1]
  1. Universidade Federal de Uberlândia, Instituto de Química, 38400-902 Uberlândia, MG (Brazil)
  2. Universidade Estadual Paulista, Instituto de Química, 14800-900 Araraquara, SP (Brazil)
Publication Date:
OSTI Identifier:
22341865
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 49; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CRYSTALLIZATION; FERRITES; FIELD EMISSION; GOETHITE; GRAPHITE; HEMATITE; IRON OXIDES; MICROWAVE HEATING; NANOSTRUCTURES; NUCLEATION; ORTHORHOMBIC LATTICES; OXIDATION; RAMAN SPECTROSCOPY; SCANNING ELECTRON MICROSCOPY; SYNTHESIS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION