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Élaboration de nanostructures d’oxydes métalliques par post-décharge micro-ondes pour la photolyse de l’eau

Abstract : In this manuscript, metallic oxide nanostructures were synthesized by the oxidation of iron, iron-copper and copper-zinc thin films by means of a plasma afterglow. Thin films were deposited by magnetron sputtering. The use of plasma afterglows allows a lowering of the temperature compared with the thermal oxidation conditions, given that molecular oxygen is excited or dissociated, which provides more reactive species such as singlet oxygen or atomic oxygen. This oxidation at moderate temperature promotes anisotropic crystal growth. The oxidation of iron–copper thin films leads to the synthesis of Fe2O3 nanoblades and CuO nanowalls, nanotowers and nanowires. The surface distribution of these nanostructures depends on the oxidation temperature, the concentration of the reactive species and the initial composition of the thin layers. The oxidation of copper-zinc thin films leads to the synthesis of ultra-thin ZnO nanowires in which quantum confinement could occur. As-grown nanostructures were characterized by various techniques (electron microscopy, X-ray diffraction and secondary ion mass spectrometry). The growth mechanisms described for these nanostructures relies on the role of stress, temperature, reactive species concentration and on the effect of underlying grain size. As-synthesized nanostructures will serve as photocatalysts to produce hydrogen by water splitting. In addition, ultra-thin ZnO nanowires will also serve as photocatalysts for water purification
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https://tel.archives-ouvertes.fr/tel-01834604
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Submitted on : Tuesday, July 10, 2018 - 5:05:06 PM
Last modification on : Monday, April 6, 2020 - 2:44:04 PM
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DDOC_T_2017_0312_IMAM.pdf
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  • HAL Id : tel-01834604, version 1

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Abdallah Imam. Élaboration de nanostructures d’oxydes métalliques par post-décharge micro-ondes pour la photolyse de l’eau. Matériaux. Université de Lorraine, 2017. Français. ⟨NNT : 2017LORR0312⟩. ⟨tel-01834604⟩

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