| Titre : |
Elaboration et étude des propriétés physiques et chimiques de nanopoudres d’oxyde de zinc pour une application en photocatalyse hétérogène. |
| Type de document : |
texte imprimé |
| Auteurs : |
Sofiane Harouni, Auteur ; Noura Boulares, Directeur de thèse |
| Mention d'édition : |
01/03/2020 |
| Editeur : |
جامعة الإخوة منتوري قسنطينة |
| Année de publication : |
2020 |
| Importance : |
158 f. |
| Format : |
30 cm. |
| Note générale : |
1 copies imprimées disponibles
|
| Langues : |
Français (fre) |
| Catégories : |
Français - Anglais
Physique
|
| Tags : |
Sciences des matériaux: Semiconducteur ZnO Nanopoudres Sol-gel SPVD DRX RAMAN UV-visible Photocatalyse Adsorption Dégradation Photocatalytique Colorant Nanopowders Photocatalysis Photocatalytic degradation Dye أكسيد الزنك سول -جل التسامي-التكثيف نانوبلوري انحراف الاشعة السينسة الامتزازالتحفيز ضوئي المحفز صبغة |
| Index. décimale : |
530 Physique |
| Résumé : |
a physical method which is the Sublimation-Condensation ZnO-SPVD; and secondly, the result study aim to compare and correlate the photocatalytic efficiencies with the physicochemical properties of the catalysts synthesized with the aim of defining new efficient catalysts. The optimization of the preparation conditions for ZnO nanopowders by the sol-gel method was carried out by varying several parameters: the concentration of the precursor, the time and the temperature of the gelation. Structural and morphological characterizations were obtained using X-ray spectra, Raman spectroscopy and scanning electron microscopy (SEM). The XRD results indicate that the powders obtained from the two techniques have a hexagonal ""würtzite"" structure, a nanometric particle size. The UV-Visible spectroscopy measurements reveal that all the studied ZnO powders exhibit the absorption edge in the UV region, this result suggests that the photocatalytic activity could be better under irradiation with UV light. The obtained results indicate that the photocatalytic activity was correlated to the particle sizes of catalysts. The catalyst prepared by the physical method (ZnO-SPVD) exhibits a higher photoactivity to degrade GV dye than the catalyst prepared by the chemical method (ZnO-SG). The experiments were carried out in the presence of each of ZnO-SPVD or ZnO-SG to investigate the factors that influence the photocatalytic degradation of GV, such as the adsorption amount, pH of dye solution, electron acceptors (H2O2), and the presence of inorganic species commonly present in real wastewaters (HCO3-). The experimental results showed that the adsorption on the surface of both samples was an important parameter controlling the photocatalytic activity. For both catalysts, the degradation rate in alkaline medium was higher than in natural and acid medium. The presence of the H2O2 and HCO3- ions increased the effectiveness of the photodegradation. |
| Note de contenu : |
Annexes. |
| Diplôme : |
Doctorat en sciences |
| En ligne : |
../theses/physique/HAR7625.pdf |
| Format de la ressource électronique : |
pdf |
| Permalink : |
index.php?lvl=notice_display&id=11461 |
Elaboration et étude des propriétés physiques et chimiques de nanopoudres d’oxyde de zinc pour une application en photocatalyse hétérogène. [texte imprimé] / Sofiane Harouni, Auteur ; Noura Boulares, Directeur de thèse . - 01/03/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 158 f. ; 30 cm. 1 copies imprimées disponibles
Langues : Français ( fre)
| Catégories : |
Français - Anglais
Physique
|
| Tags : |
Sciences des matériaux: Semiconducteur ZnO Nanopoudres Sol-gel SPVD DRX RAMAN UV-visible Photocatalyse Adsorption Dégradation Photocatalytique Colorant Nanopowders Photocatalysis Photocatalytic degradation Dye أكسيد الزنك سول -جل التسامي-التكثيف نانوبلوري انحراف الاشعة السينسة الامتزازالتحفيز ضوئي المحفز صبغة |
| Index. décimale : |
530 Physique |
| Résumé : |
a physical method which is the Sublimation-Condensation ZnO-SPVD; and secondly, the result study aim to compare and correlate the photocatalytic efficiencies with the physicochemical properties of the catalysts synthesized with the aim of defining new efficient catalysts. The optimization of the preparation conditions for ZnO nanopowders by the sol-gel method was carried out by varying several parameters: the concentration of the precursor, the time and the temperature of the gelation. Structural and morphological characterizations were obtained using X-ray spectra, Raman spectroscopy and scanning electron microscopy (SEM). The XRD results indicate that the powders obtained from the two techniques have a hexagonal ""würtzite"" structure, a nanometric particle size. The UV-Visible spectroscopy measurements reveal that all the studied ZnO powders exhibit the absorption edge in the UV region, this result suggests that the photocatalytic activity could be better under irradiation with UV light. The obtained results indicate that the photocatalytic activity was correlated to the particle sizes of catalysts. The catalyst prepared by the physical method (ZnO-SPVD) exhibits a higher photoactivity to degrade GV dye than the catalyst prepared by the chemical method (ZnO-SG). The experiments were carried out in the presence of each of ZnO-SPVD or ZnO-SG to investigate the factors that influence the photocatalytic degradation of GV, such as the adsorption amount, pH of dye solution, electron acceptors (H2O2), and the presence of inorganic species commonly present in real wastewaters (HCO3-). The experimental results showed that the adsorption on the surface of both samples was an important parameter controlling the photocatalytic activity. For both catalysts, the degradation rate in alkaline medium was higher than in natural and acid medium. The presence of the H2O2 and HCO3- ions increased the effectiveness of the photodegradation. |
| Note de contenu : |
Annexes. |
| Diplôme : |
Doctorat en sciences |
| En ligne : |
../theses/physique/HAR7625.pdf |
| Format de la ressource électronique : |
pdf |
| Permalink : |
index.php?lvl=notice_display&id=11461 |
|
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