Browsing by Author "Khezami, Lotfi"

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    Efficient photodegradation of azucryl red by copper-doped TiO2 nanoparticles-experimental and modeling studies
    (Springer, 2021) Kerrami, Ahmed; Khezami, Lotfi; Bououdina, Mohamed; Mahtout, Laila; Modwi, Abueliz; Rabhi, Souhila; Bensouici, Faycal; Belkacemi, Hayet
    This research aims to investigate the effect of copper doping on the photocatalysis performance of TiO2nanoparticles for disposalwastewater from organic pollutants. X-ray diffraction analysis manifests the crystallization of a rutile phase for pure and copper-doped TiO2except for 2% resulting in a rutile-to-anatase phase transformation. The crystallite size is found less affected by Cudoping, i.e., ~30 nm. BET analysis indicates a decrease in the specific surface area as the doping loading increases. Scanningelectron microscopy observations reveal spherical particles at the nanometer range for pure TiO2and then larger agglomerates ofultrafine particles with Cu doping. FTIR analysis notifies the existence of hydroxyl groups, which will promote the photocatalysisprocess. The photodegradation of azucryl red (AR) has been investigated under different conditions; i.e., Cu-loading, initialconcentration of AR, and pH. The kinetics of the photodegradation process is further found to comply with the Lagergren kineticlaw, regardless the experimental conditions. Nevertheless, the photodegradation process is not only controlled by the intra-particle diffusion mechanism, but also by mass transfer through a liquid film boundary. The maximum degradation of AR,i.e., 86%, has been achieved at pH = 5.0 during 60 min of contact time for the 2% Cu doping, with effective regeneration. TheFreundlich model exhibits a better fitting for AR dye photodegradation equilibrium data, compared to Langmuir, Temkin, andDubinin-Radushkevich
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    Synthesis, structural, and opto-electrochemical properties of cobalt aluminate type spinel and its use with ZnO for Cr(VI) photoreduction
    (Springer, 2021) Bouallouche Née Saadi, Rachida; Kebir, Mohammed; Nasrallah, Noureddine; Saib, Faouzi; El Jery, Atef; Khezami, Lotfi; Trari, Mohamed
    The discovery of the occurrence of inorganic pollutants in surface waters is identified in the system assessment quality. The most harmful elements are pesticides, persistent organic pollutants, pharmaceuticals, personal care products, and heavy metals are still dangerous to the environment due to their general uses. Chromate has the largest concentration compared to the other metals in the wastewater industries. This work evaluates the application of the spinel p-CoAl2O4 as a photocatalyst prepared by the nitrate synthesis process to reduce Cr(VI), a hazardous metal for the environment. The photocatalyst was characterized using thermal analysis (TG), X-ray diffraction, UV-diffuse reflectance spectroscopy, scanning electron microscopy, fluorescent X-ray, Fourier transform infrared spectroscopy, electrical conductivity, and photoelectrochemically. The results showed that the efficiency of optimum reduction of Cr(Vl) to Cr(IIl) photoreduction is more effective (77%) for pH = 3.6 than that at high pH values up to 8 (7%). Moreover, the effect of the hetero-system CoAl2O4/ZnO on photocatalytic efficiency was investigated. The photocatalytic activity increases up to 99% with 1 g L-1, a total catalyst dosage over the hetero-system CoAl2O4/ZnO at a ratio of 75%/25%. This data is better relative to CoAl2O4 or ZnO alone. The Cr(VI) photoreduction activity improvement was caused by the best separation and the photogeneration of electron-hole on the CoAl2O4/ZnO surfaces. Finally, the Lagergren pseudo-first-order and the Langmuir-Hinshelwood models fit well the experimental kinetics