Browsing by Author "Hamidouche, Fahim"

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Catalytic Activity of Phenol Oxidation over Iron and Cooper-Exchanged Pillared Bentonite
(Springer Nature, 2024) Chellal, Khalida; Hamidouche, Fahim; Boudieb, Naima; Meguellati, Zineb; Trari, Mohamed
Al, mixed Al–Fe and Al–Cu pillared clays were prepared by the conventional method in a diluted medium with two additional parameters for the synthesis; the first one is the cooling of the clay suspension and the second is the exchange between the clay and metal solutions before pillaring with the polymeric mixed solution. The solids were characterized by X-ray diffraction (XRD), N2 adsorption and H2-TPR. The effects of the atomic ratio (M/Al + M) and hydrolysis molar ratio (OH/M), on the basal spacing and/or the specific surface were examined. The exchange does not seem to fix more Cu as in the case of Fe. The dispersion of the cold clay suspension, before pillaring, leads to a greater basal spacing of the solid at room temperature. In the case of mixed Al–Fe exchanged and/or pillared clays calcined at 350 °C, the cold dispersion of the clay suspension increases the basal spacing from 15.89 to 17.44 Å and from 15.32 to 16.07 Å for MR-AlFe (10) and Fe/MR-AlFe (10) respectively. Catalytic Wet Peroxide Oxidation (CWPO) of phenol under mild conditions (25 °C, 1 atm) was carried out without correction of pH. Mixed Al–Fe and Al–Cu pillared clays have comparable performances, although they showed some differences in the H2O2 decomposition kinetics. A total conversion of H2O2 is obtained without the complete phenol conversion over mixed Al–Fe pillared clays suggesting the presence of active species in these catalysts. In a slight excess of H2O2, the activity increases for all Fe-based clays catalysts with increasing the Fe content. A total conversion of phenol was obtained within 15 h of reaction over Fe/MR-AlFe (10) and after extending the reaction time to 30 h in the presence of Fe/MR-Al. On the contrary, MR-AlFe (10) only converted 57.12% under the same conditions. MR-AlFe (10) has the greater basal space (17.44 Å) and is more active for H2O2 decomposition than Fe/MR-Al, which certainly allowed greater accessibility of the reactant to the Fe-species. Fe exchanged and post-pillared clay with mixed (Al–Fe) solution containing 10% Fe expressed as molar percentage {Fe/MR-AlFe (10)} was the most efficient for this reaction combining good catalytic activity with high stability against iron leaching (0.02%). It showed a total phenol degradation, the highest H2O2 decomposition (85.7%) and more than 80% of TOC removal after 15 h of reaction.
Effect of Hematite on the Energy Storage Performance of Polyaniline/Zeolite HY/α-Fe2O3 Nanocomposite Supercapacitor Electrode
(Springer, 2020) Ghebache, Zohra; Zitouni, Safidine; Hamidouche, Fahim; Boudieb, Naima; Benaboura, Ahmed; Trari, Mohamed
The main goal of the present work is the elaboration of new nanocomposite conducting poly(aniline) with α-Fe2O3 nanoparticles in the presence of zeolite HY acid in aqueous electrolyte by chemical oxidative polymerization. Various formulations of the polymer were synthesized (5, 10, and 20% of α-Fe2O3) and the nanocomposites poly(aniline)/HY/α-Fe2O3 have been characterized by X-ray diffraction (XRD), SEM analysis, and FT-IR spectroscopy. The electrical conductivity and the UV–visible spectroscopy of the nanocomposites were also investigated. In addition, the electrochemical properties were studied by cyclic voltammetry. (CV) and electrochemical impedance spectroscopy. The optimal ratio between α-Fe2O3 and poly(aniline)/HY was found to be 5 wt%. The specific capacitances of poly(aniline)/HY and nanocomposite were found to be be 630, and 1000 F g−1 respectively at a scan rate of 5 mV/s. Besides, the material possesses a high energy density of 88.88 Wh kg−1 and a maximum power density of 1632.3 W kg−1. These electrochemical results indicate that the PANI/HY/α-Fe2O3 nanocomposites is an attractive candidate for the application in the high-performance energy storage systems.
Elaboration des couches minces et études des propriétés structurelles et électro-optiques des composites SiC/Polymère/Si
(2019) Belhaouri, Ibtissem; Hamidouche, Fahim
L’objectif principal de ce présent travail était d’élaborer des couches minces composites à base de nanoparticules de carbure de silicium incorporées dans une matrice organique, en utilisant un polymère qui est le polyvinyle alcool (PVA). L’utilisation des nanoparticules de carbure de silicium a un effet très important dans la conversion d’ondes comme étant des nanoparticules luminescentes. Bien évidemment le dépôt de ces couches composites sur les substrats en silicium joue le rôle d’une couche antireflet de descendent luminescent (LDS), d’une part et de l’autre part la texturisation des substrats nanofils et nanopyramides réduit aussi la réflectance des rayons solaires et par conséquence une amélioration de rendement de ce type de cellules solaires est très remarquable. Afin de confirmer cette propriété plusieurs techniques de caractérisation structurelles et électro-optiques ont été effectuées que se soient sur les matériaux de basse (PVA,SiC) ou bien sur les couches composites élaborés et même sur une cellule solaire avec et sont dépôt de la matrice SiC /PVA. Vu les résultats obtenus l’utilisation de la matrice SiC/PVA comme couche de conversion d’onde dans le domaine de photovoltaïque est considéré très bénéfiques.
Elaboration et caracterisations des nanocomposites conducteurs a base de (PPY(CL)/ZEOLITHE HY/TIO2)
(2013) Hamidouche, Fahim
Ce travail de recherche est basé sur l'étude de la polymérisation chimique des nanocomposites conducteurs à base de PPy(Cl) comme matrice, la Zéolithe HY et le TiO2 de type Anatase comme renforts, à la température ambiante et pression atmosphérique, en utilisant FeCl3 comme initiateur de la réaction et dopant en même temps. Après la caractérisation des produits de base, nous avons procédés en premier lieu sur la polymérisation du pyrrole avec déférents rapports molaires de [FeCl3]/[Pyrrole] dans un milieu aqueux , suivi par une série de caractérisations pour les polymères obtenus. Le bon rapport remporté a été utilisé pour la préparation des nanocomposites à base de PPy(Cl)/ Zéolithe HY et PPy(Cl)/TiO2, qui sont optimisés à leurs tours pour avoir un meilleur nanocomposite à base de PPy(Cl)/Zéolithe HY/TiO2. Après chaque synthèse, le produit élaboré est caractérisé par: IRTF, ATD, DSC, ATG, MEB, UV-Visible, DRX, potentiel Zêta et mesure de la conductivité électrique pour confirmer le bon déroulement du processus de synthèse et d'étudier leur propriétés afin d'envisagé des applications spécifiques
Enhancing the Supercapacitive and Conductivity Properties of Polypyrrole via In-situ Polymerization with HY Zeolite Nanoparticles
(Springer link, 2020) Hamidouche, Fahim; Ghebache, Zohra; Boudieb, Naima; Sanad, Moustafa M. S.; Djelali, Nacer-Eddine
Highly stable zeolite HY/polypyrrole composite material was successfully fabricated by applying in-situ chemical polymerization approach. The functional properties of the prepared zeolite HY particles/polypyrrole were systematically inspected using XRD and FT-IR characterization techniques. Thermal stability and optical properties were consistently studied using TGA and UV–Vis spectroscopy techniques. The value of band gap energy (Eg) of the produced zeolite HY/polypyrrole nanocomposite was lower than the values of its individual components. Cyclic voltammetry studies concluded that HY/polypyrrole electrode material with mass ratio ~ 0.4 prepared at cold polymerization conditions ~ 0 °C exhibited the highest values of specific capacitance ~ 310 F g−1 and ionic conductivity ~ 1.7 S cm−1. The fabricated zeolite HY/polypyrrole composite material at 0 °C revealed a capacitance retention ~ 93.4%, while the other composite prepared at 25 °C possessed a capacitance retention ~ 72.4% after 500 charge/discharge cycles. The electrochemical impedance spectroscopy (EIS) measurement for the optimized composite electrode materials confirmed the cyclic stability after long term cycling of about 5000 cycles as a result of higher ionic conductivity between active material and ionic species than that value before cycling
Etude de l'influence du dopage sur les polymères conducteurs utilisés comme matrices dans les nanocomposites multifonctionnels
(2018) Hamidouche, Fahim
Dans le cadre de l'utilisation des complexes de coordination comme électrodes dans les batteries au lithium, nous avons pu démontrer que le potentiel de fonctionnement de ces matériaux est ajustable selon la nature du métal coordonné. Partant de cette sélection, des matériaux complexes polymère de coordination bipyridinique de fer ont été élaborés. Plusieurs stratégies ont été employées se distinguant sur la procédure de fabrication de ce polymère. Les meilleurs complexes ont été ceux obtenus par une polymérisation chimique d'un dérivé du complexe tris-bipyridinique présentant trois unités vinyle polymérisables. La seconde partie s'intéresse à la formulation et la caractérisation de nouveaux types d'électrodes pour super-condensateurs. Dans le cas de NPC à base de MMT/PPy(Cl), des capacités relativement élevées ont été obtenues en milieu aqueux, rivalisant avec les résultats de la littérature i .e. 410 F.g-1. Ces capacités ont été " optimisées " en contrôlant la température, le rapport montmorillonite/pyrrole, le pH de la solution durant l'élaboration du matériau nanocomposite. Ces résultats sont en partie expliqués par l'impact de ces paramètres sur la conductivité du nanocomposite. Les mêmes phénomènes sont observés dans le cas des NPCs à base de PPy(Cl) avec la ZHY et la Z4A, où des valeurs de 310 F.g-1 / 1,7 S.cm-1 et 380 F.g-1 / 6,6 S.cm-1 sont respectivement observé. Les propriétés optimales dans le cas de NPC à base de ?Fe2O3/PPy(Cl) sont obtenues avec un rapport massique de 0,3 à basse température, ou une conductivité de 9 S.cm-1 et une capacité spécifique de 345 F.g-1 sont enregistrée en milieu aqueux. L'étude préliminaire que nous avons menée sur ces NPC a donnée des renseignements d'ordre qualitatif, et la compréhension d'un mélange de deux constituants nécessite une étude plus approfondie
Montmorillonite/Poly(Pyrrole) for Low-Cost Supercapacitor Electrode Hybrid Materials
(MDPI, 2024) Hamidouche, Fahim; Ghebache, Zohra; Lepretre, Jean-Claude; Djelali, Nacer-Eddine
Conductive polymers such as polypyrrole have been widely used as pseudo-capacitive electrodes for supercapacitors. This work demonstrates a simple method to improve the performance of conductive polymer electrodes by adding montmorillonite in order to perform capacitive behavior. Conductive composite polymers (CCPs) based on montmorillonite/polypyrrole (MMT/PPy(Cl)) have been synthesized by polymerization using FeCl3 as an oxidizing agent. During the preparation of CCP, the effect of MMT/pyrrole mass ratio and the influence of the amount of added H+ and temperature of the synthesis medium on the electrochemical performance of the composite have been investigated. The investigation associated with conductivity measurement allowed us to determine the best conditions to reach a high specific capacitance of 465 F gr−1 measured by cyclic voltammetry with respect to the CCP synthesized at ambient temperature (220 F gr−1) and a 35% increase in capacity compared to its homologue synthesized in neutral conditions at a low temperature. These performances have been advantageously correlated both to the edge acidity of the host material and to the evolution of its conductivity according to the preparation conditions. The galvanostatic charge/discharge tests also confirm the stability of the obtained composite, and a capacitance of 325 F g−1 for the best CCP is recorded with a regime of 1 A g−1. In addition, the durability of the device shows that the proposed material has a relatively good stability during cycling.
Study of the Influence of Metal Surface Quality on the Performance of an Epoxy Coating
(Elsevier, 2023) Boudieb, Naima; Bounoughaz, Moussa; Hamidouche, Fahim; Ghebache, Zohra
In the present work, an EC used for steel corrosion protection was characterized by Ec techniques. This study aimed to describe the effect of the steel roughness surface on the performance of EC, through EIS and other methods. The studied metal was a low-strength CS immersed in a 3.5% NaCl solution. The CS surface was obtained by polishing it (metal electrodes) with an abrasive paper of 120, 600 and 1200 mesh. Then, the electrodes were painted with an anti-corrosive EC, which contained Zn3 (PO4)2 as an anti-corrosion agent. The study of the influence of the CS surface Ra and its corrosion behaviour and of the evolution of the protective capacity systems on the EC performance was made by stationary (Ecorr and Tafel plot) and no-stationary Ec techniques (EIS and CA). In order to confirm the detachment and blistering on the coating, the coated CS samples were analyzed by a salt spray in a 7.69 % NaCl solution, with an IT of 15 days. The obtained results showed that the CS surface state directly influenced the coating performance and the Ec parameter values variation, as a function of IT in the NaCl solution. EIS was the most valid Ec method for the studied coatings.
Synthesis and characterization of HY Zeolite-doped poly(aniline) by chemical oxidation method
(2016) Ghebache, Zohra; Djelali, Nacer-Eddine; Zitouni, Safidine; Hamidouche, Fahim
Synthesis of nanocomposites based semiconductors of PPy(Cl)/Zeolite HY
(Syscom 18 SRL, 2015) Hamidouche, Fahim; Djelali, Nacer-Eddine
Zeolite 4a coating by polypyrrole doped with chlorine
(Materiale plastice, 2016) Hamidouche, Fahim; Djelali, Nacer-Eddine; Ghabache, Zohra
An organic–inorganic conductor’s Polypyrrole(Cl)/Zeolite 4A (PPy(Cl)/Z4A) was successfully synthesized by chemical oxidative polymerization at low and room temperature, using FeCl3 as initiator the reaction and dopant at the same time. After characterization, commodity we methods primarily on the polymerization of pyrrole with different molar ratios of [FeCl3]/[Pyrrole] in an aqueous medium, followed by a series of characterizations for the polymers obtained. The right ratio was used for the preparation of nanocomposites PPy(Cl)/Z4A. After each synthesis, the developed product is characterized by FTIR, SEM-EDX, XRD, electrical conductivity and cyclic voltammetry, in order to confirm the success of the process of synthesis and study their properties to specific applications envisaged