کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1506617 | 993802 | 2009 | 7 صفحه PDF | دانلود رایگان |
Fe-SBA-15 materials with different Si/Fe ratios (Si/Fe = 100, 60, 15) have been synthesized by hydrothermal method and characterized by several spectroscopic techniques. Electron spin resonance and Mössbauer spectroscopy, along with electron microscopy and X-ray diffraction, allowed differentiation of several iron species. These species correspond to hematite particles, very small “isolated” or oligomeric FeIII species possibly incorporated in the mesoporous silica wall, and FeIII oxide clusters either isolated or agglomerated, forming “rafts” at the surface of the silica and exhibiting ferromagnetic ordering. Because of their agglomeration, these clusters appear with a two-peak size distribution, with one peak corresponding to the isolated clusters formed in the mesopores and still embedded in them and the other corresponding to the agglomerates spread on the surface of the mesoporous silica particles.
We report in detail the characterization of Fe-SBA-15 materials by N2 adsorption measurements, X-ray diffraction, UV–vis spectroscopy, high-resolution transmission electron microscopy (HRTEM) with EDX analyses, electron spin resonance (ESR) and Mössbauer spectroscopy.Figure optionsDownload as PowerPoint slide
Journal: Solid State Sciences - Volume 11, Issue 9, September 2009, Pages 1549–1555