http://archives.univ-biskra.dz/handle/123456789/25619 2026-04-16T12:59:07Z http://archives.univ-biskra.dz/handle/123456789/31483 Titre: Elaboration et caractérisation d’un matériau composite à base de BIT Aurivillius Auteur(s): OUNIS AMINA Résumé: This research focuses on the synthesis and characterization of composite materials based on triple-layer Bi4Ti3O12 (BIT) Aurivillius doped with various cations, such as indium and tantalum, with a percentage of 8%. The main objective is to determine the effect of doping and heterojunctions on the structure, morphology and photocatalytic properties of BIT-based photocatalysts synthesized by the molten salt method. Analyses were conducted to characterize the structural, morphological and optical properties of the samples, such as X-ray diffraction, Fourier transform infrared, Raman spectroscopy, scanning electron microscopy, BET surface analysis, UV-VIS and PL photoluminescence. The obtained results indicate that cationic doping and composite materials based en triple layer Aurivillius Bi4Ti3O12 improve the photocatalytic efficiency for the decomposition of an organic pollutant such as Rhodamine B under the influence of UV irradiation, with degradation rates reaching 97.63% en 180 min, with first order reaction kinetics, making them highly efficient photocatalysts for applications such as pollutant degradation and water purification. Description: Génie des procédés de l’environnement 2025-01-01T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/31482 Titre: Elaboration et caractérisation d'un composite à base biochar et ses applications à la photocatalyse et l'adsorption des polluants Auteur(s): Hamida khadidja Résumé: Potatoes are one of the most important crops for extensive consumption. They are cultivated in large quantities, especially in the region of Oued. This big amount results a large residues of potato plant which we have exploited as raw material for preparing activated carbon. The raw potato plant (PPT) was modified with chemical activation: ZnCl2 (PPT-ZnCl2), NaOH (PPT-NaOH) and HCl (PPT-HCl) to improve its adsorption capacity for removal of rhodamine b (RhB) in aqueous solutions. The characterization of these activated carbons (adsorbents) showed that they contain a crystalline structure with a carbon content and a porous surface due to chemical activation, followed by series of surface functions that react with pollutants during the adsorption of RhB. The results showed that the adsorption efficiency of RhB reached 98.95%, 96.1%, and 86.65% for PPT-ZnCl2, PPT-NaOH, and PPT-HCl respectively. The RhB adsorption kinetics on each adsorbent is well described by the pseudo-second order model for PPT-ZnCl2 and Elovich for PPT NaOH, PPT-HCl, and the Freundlich isotherm was best suited. The maximum Langmuir adsorption capacities obtained are in the following order: 140.34 mg/g (PPT-ZnCl2)>86.58 mg/g (PPT-NaOH)>44.48 mg/g (PPT-HCl). The PPT-ZnCl2(1-x)/Bi4Ti3O12(x) composites, abbreviated to (PPT-ZnCl2(1-x)/BTO(x)), with x= 30 wt%, 50 wt% and 70 wt%, were formed using a simple ethanol technique to create the heterojunction between pure BTO and PPT-ZnCl2. This gave a product with strong optical properties for the removal of (RhB). The composite PPT-ZnCl2(0.7)/BTO(0.3) showed a better and higher visible absorption, the role of PPT-ZnCl2 in the reduction of band gap compared to pure BTO, this showed a faster degradation compared to pure BTO. PPT-ZnCl2(0.7)/BTO(0.3) showed the best photocatalytic performance with a 99.9% degradation rate after 20 min. Description: Génie chimique 2025-01-01T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/31481 Titre: etude expérimentale et modélisation de l élimination des polluants organique dans les efflents liquides industriels Auteur(s): benaoune saliha Description: génie des procèdes des matériaux 2025-01-01T00:00:00Z http://archives.univ-biskra.dz/handle/123456789/31480 Titre: Optimisation des propriétés physico-chimiques et photocatalytiques des couches minces à base d’oxyde Auteur(s): Hadjer Barkat Résumé: In this work, undoped and Ba-doped ZnO thin films were deposited on glass substrates by a simple and cost effectiveness successive ionic layer adsorption and reaction (SILAR) method. These films were investigated using various techniques. To optimize the quality of our films, we have studied the influence of dopant concentrations, deposition cycles number, and annealing temperature on film’s structural, morphological, optical, and photocatalytic properties. All samples exhibited a polycrystalline nature with wurtzite hexagonal phase. The X-ray diffraction patterns shows that the 5 wt. % Ba-doped ZnO crystallization is better than undoped samples, with a (100) preferred orientation. SEM images revealed that the films were well adherent and uniform. UV- Visible depicted that the transmittance of the films increased as increasing of Ba-doping concentrations, demonstrating improved optical transparency. The 5 wt.% Ba-doped ZnO films displayed the highest photocatalytic efficiency, achieving 95.78% degradation of MB under sunlight irradiation over 5 hours. This sample showed exceptional stability and reusability, retaining its performance over five cycles. On the other hand, 5 wt.% Ba-doped ZnO films deposited at different cycle numbers showed that an increase in deposition cycles led to better crystallinity at higher cycles. As a result, the photocatalytic efficiency improved to 93.51% at 15 cycles. Furthermore, the results showed that the process of annealing temperature at 450°C enhanced the crystallinity, the optical properties, and the photocatalytic efficiency of Ba-doped ZnO films, achieving 96.17% degradation of MB, and which gradually decreased to 94.89% after five successive cycles. Description: Génie des Matériaux 2025-01-01T00:00:00Z