Синтез, структура та електрохімічні властивості ультрадисперсного аморфного ?-FeOOH
The aim of the article is to findrelationshipsbetween synthesis conditions and phase composition, magnetic microstructure and electrochemical properties of ultrafine amorphous iron hydroxide phases obtained by iron citrate sol hydrothermal treatment. The sol of iron citrate was formed by mixing of 0...
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| Date: | 2016 |
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| Main Authors: | , , , , , |
| Format: | Article |
| Language: | Ukrainian |
| Published: |
Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2016
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| Subjects: | |
| Online Access: | https://www.cpts.com.ua/index.php/cpts/article/view/388 |
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| Journal Title: | Chemistry, Physics and Technology of Surface |
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Chemistry, Physics and Technology of Surface| Summary: | The aim of the article is to findrelationshipsbetween synthesis conditions and phase composition, magnetic microstructure and electrochemical properties of ultrafine amorphous iron hydroxide phases obtained by iron citrate sol hydrothermal treatment. The sol of iron citrate was formed by mixing of 0.3 M iron nitrate aqueous solutions with citric acid. Hydrothermal treatment of iron citrate was carried out at 120°C for 5 hours with the next annealing of precipitation at 150, 200, 250, 300 and 350°C in air for 2 hours. X-ray analysis and M?ssbauer spectroscopy were used for phase composition and magnetic microstructure control of the obtained iron hydroxides. All the synthesized materials were X-ray amorphous so the M?ssbauer spectroscopy was used for phases recognition. In has been determined that the hydrothermal treatment of iron citrate solution at 120°C for 5 hours leads to Fe(OH)3formation.The annealing in the temperature range of 150–200 °C causes the reduction of iron Fe3+ ? Fe2+as aresult of material dehydration . Under this condition the composite Fe(OH)3/ Fe(OH)2 was formed with the pentahydrate iron citrate C6H5O7Fe?5H2O and iron oxalate FeC2 O4 ·2H2 O presence . Amorphous ultrafine ? -FeOOH was obtained after Fe(OH)3annealing at 250°C for 2 hours . It has been found that after annealing at 350°Cphase transformation of ?- FeOOH??-Fe2 O3has occurred. The sizes of coherent scattering regions for ?-Fe2 O3 phase are about 15.0±1.5 nm. The electrochemical properties of ultrafine amorphous ?-FeOOH and composite ?-FeOOH/carbon nanotubes in 3.5M KOH aqueous solution were studied. The efficiency of ?-FeOOH/carbon nanotube as potential electrode material for supercapacitor was shown. |
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