Published online by Cambridge University Press: 09 December 2019
Nanoparticles and nanopores of iron oxide were synthesized by electrochemical anodization, in an electrolytic medium of ammonium fluoride (NH4F), deionized water and ethylene glycol. After anodization, the Fe foils were annealed at 450 °C for 2 hours. Different anodization times and two concentrations of NH4F (0.1 M and 1.2 M) were evaluated, under static conditions at room temperature. Scanning Electron Microscopy showed nanopores (0.1 M) and nanoparticles (1.2 M). Eight vibration modes characteristic of α-Fe2O3 were found with Raman spectroscopy technique. Relationship between the modes Eu(LO) and 2Eu(LO) was found, therefore, their association with the disorder in the crystalline structure can be determined and it was also found that 2Eu(LO) intensity mode at a concentration of 1.2 M is larger than 0.1 M nanostructures, the FWHM of the A1g mode at 227 cm-1 corresponding to the Fe3+ ions and the Eg at 293 cm-1 mode caused by the O2- ions was also analyzed and founded that the crystalline structure of hematite can be determined by the A1g mode at 227 cm-1.