Browsing by Author "Bououdina, M."

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Cu2O addition and sintering temperature dependence of structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics
(Elsevier, 2020) Djafar, Rabah; Boumchedda, K.; Chaouchi, A.; Fasquelle, D.; Sedda, K.; Brahimi, S.; Khalfaoui, K.; Bououdina, M.
This study is aimed in the replacement of commonly used (CuO) by Cu2O in the synthesis of perovskite CaCu3Ti4O12 (CCTO) phase by the solid-state reaction method. The XRD analysis of powder calcined at 1100 °C and ceramics sintered at different temperatures show that the CCTO phase was well crystallized with the presence of small quantities of additional phases. The SEM/EDS analysis of prepared pellets show that the formation of Cu2O/CuO phase occurs above 950 °C, resulting in enhanced densification at 1050 °C (>96%). However, it is found that the Cu2O-based CCTO begins to degrade around 1090 °C. The densification after sintering at 1050 °C reaches 96%, meanwhile dielectric constant and loss tangent values are optimum in the low frequency range (<103 Hz); i.e. 13378 and 0.177, respectively. This favors the use of Cu2O instead of CuO in CCTO ceramics for applications at low frequencies
Dielectric properties of nanocrystalline CaCu3Ti4O12 (CCTO) ceramics fabricated from Algerian limestone raw material
(Elsevier, 2023) Djafar, Rabah; Boumchedda, K.; Fasquelle, D.; Chaouchi, A.; Sedda, K.; Bououdina, M.; Bellucci, S.; Bánhegyi, G.
Algerian natural limestone was used to fabricate the perovskite CaCu3Ti4O12 phase (CCTO) to replace commercial calcium carbonate (CaCO3) powder by a solid-state method. X-ray diffraction analysis of CCTO ceramics sintered at 1010 °C manifested the formation of well-crystallized pure (CCTO) phase with narrow crystallite size (43–99 nm) without any additional phases after sintering beyond 4 h. Thermal analysis by DSC indicated that CCTO phase is stable up to 1151 °C, afterwards it decomposes into CaTiO3 and TiO2 and accompanied by the segregation of the CuO/Cu2O phase. Scanning electron microscopy observations of the ceramics sintered at 1010 °C showed that most of the grains have an average particle size in the narrow range of 1–2 μm. The sintered pellet at 1010 C° for 14 h showed the optimum density (>94%). This study highlights the importance of using natural calcium carbonates (extracted from Guelma limestone in Algeria) as potential replacement to commercial counterpart for the fabrication of dense well-crystallized perovskite-type ceramics with controlled particle size distribution as promising candidates for electronic applications
Effect of acid nature in the starting solution on surface and photocatalytic properties of TiO2 thin films
(Elsevier, 2014) Bensouici, F.; Souier, Tewfik; Iratni, A.; Dakhel, A.A.; Tala-Ighil, Razika; Bououdina, M.
Effect of Er doping on the microstructural, optical, and photocatalytic activity of TiO2 thin films
(Iop science, 2018) Abdelali, Aouina; Bensouici, F.; Bououdina, M.; Tala-Ighil, Razika
anostructured Er³⁺ doped TiO2 thin films are deposited onto glass substrate via sol-gel dip-coating followed by calcination at 450 °C for 1 h. X-ray diffraction analysis confirms that the films crystallized within single tetragonal anatase phase. Atomic force microscopy observations reveal that the surface of pure TiO2 is characterized by ninepins then becomes smooth and porous for Er-doped TiO2 thin films, while the roughness decreases drastically from 17.2 to 2.6 nm with increasing Er³⁺ percentage. Wettability tests show a super-hydrophilicity character of 0.2 and 0.3%Er doped TiO2 thin films. UV–vis analysis reveals high transmittance above 85% with the presence of interferences indicating the high quality of films. Meanwhile, the energy band gap decreases slightly from 3.31 eV for un-doped to 3.26 eV for 0.4%Er, with a red-shift in the optical absorption edge. High photocatalytic activity using methylene blue indicator has been achieved for 0.2% Er³⁺–TiO2 thin film, reaching 95% for 3 h.
Nanostructured oxide materials for photodegradation of dyes
(2017) Bensouici, F.; Tala-Ighil, Razika; Bououdina, M.
Optical, structural and photocatalysis properties of Cu-doped TiO2 thin films
(Elsevier, 2017) Bensouici, F.; Bououdina, M.; Dakhel, A.A.; Tala-Ighil, Razika; Tounane, M.; Iratni, A.; Souier, T.; Liu, S.; Cai, W.
Pure and Cu+2 doped TiO2 thin films have been successfully deposited onto glass substrate by sol–gel dip-coating. The films were annealed at 450 °C for 1 h and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), UV–vis spectrophotometer and photocatalytic degradation of methylene blue. XRD confirmed the presence of two phases at higher Cu concentration; TiO2 anatase and CuO. AFM analysis showed that the surface roughness increases within increasing Cu content as well as the presence of large aggregates at higher Cu content. SEM observations confirmed the granular structure of the films, and EDX analysis revealed a low solubility limit (effective doping) of Cu into TiO2 lattice. It was found that the optical band gap energy decreases with increasing Cu content. At constant irradiation time, the photo-degradation of methylene blue rate decreased with increasing concentration of Cu+2
Sol concentration effect on ZnO nanofibers photocatalytic activity synthesized by sol–gel dip coating method
(IOP Publishing, 2017) Toubane, Mahdia; Tala-Ighil, Razika; Bensouici, F.; Bououdina, M.; Souier, M.; Liu, S.; Cai, W.; Iratni, A.
Surface, structural and optical properties dependence of Fe-doped TiO 2 films deposited onto soda–lime–glass
(Elsevier, 2020) Benyakhlef, M.; Bensouici, F.; Bououdina, M.; Dakhel, A.A.; Tala-Ighil, Razika; Toubanea, M.
In this study, pure and Fe doped TiO2 thin films have been prepared via sol-gel method using the tetraethyl-orthotitanate as source of Ti and Fe(III) nitrate as a source of Fe3+ doping. XRD patterns exhibit typical peaks of TiO2 anatase phase. SEM observations confirm the nanometer grain size (below 10 nm) without a defined shape. Optical measurements indicate a transparency in the range 80–100%, it increases with Fe doping level while the energy band gap slightly decreases; 3.36 – 3.28 eV. Wettability test shows a super-hydrophilicity of Fe3+ doped TiO2 thin films and the low contact angle is founded for 0.6%Fe. However, no enhancement in photocatalytic activity of Fe doped TiO2 thin films have been achieved. This may be attributed to sodium diffusion from the substrate. The as-prepared nanostructured Fe-doped TiO2 thin films can be used as potential candidate for self-cleaning due to the super-hydrophilicity character in the visible light
Synergistic effect of Rutile-Anatase Fe-doped TiO2 as efficient nanocatalyst for the degradation of azucryl red
(IOP Publishing, 2019) Kerrami, Ahmed; Mahtout, Laila; Bensouici, F.; Bououdina, M.; Rabhi, S.; Sakher, E.; Belkacemi, H.
The aim of this work is to reduce the impact on the environment of a basic textile dye (azucryl red) using a semiconductor TiO2 and Fe doped TiO2 powders calcined at 600 °C as catalysts. The refinements based on the Rietveld method of x-ray diffraction patterns indicate the formation of Rutile phase for un-doped TiO2, while a phase transformation into Anatase phase occurs upon Fe doping. Scanning electron microscopy analysis reveals the formation of spherical-like particles at the nanoscale that agglomerate into aggregates, meanwhile the chemical composition checked by EDX spectroscopy is close to the stoichiometry. FTIR analysis reveals the presence of OH groups that favor the photocatalytic reaction, while EPR analysis confirms the existence of Fe3+ resulting in the creation of oxygen vacancies. Excellent photocatalytic degradation of azucryl red is obtained by 0.2% Fe doped TiO2, the removal of 100% of dye is achieved within a very short time of 10 min
Synthesis, characterization and photocatalytic behavior of Ag doped TiO2 thin film
(Elsevier, 2015) Bensouici, F.; Souier, T.; Dakhel, A.A.; Iratni, A.; Tala-Ighil, Razika; Bououdina, M.
In this study, structure, microstructure, optical properties and photocatalytic degradation of Rhodamine B (RhB) have been investigated in an aqueous heterogeneous media containing pure and Ag doped TiO2 nanostructures thin films which were prepared by a simple sol–gel route. Thermal analysis demonstrated that Ag content decreased the temperature of anatase-to-rutile phase transformation. X-ray diffraction analysis confirmed that the prepared nanostructures crystallize within anatase-type structure and that the dopant Ag ions were not fully incorporated within TiO2 host lattice, meanwhile both the refractive index and optical band gap were affected by Ag concentration. The photodegradation of Rhodamine B under UV-C radiation by using pure and Ag-doped TiO2 nanostructures showed that Ag played an important role in a significant improvement of the photodegradation efficiency and that the optimum content of Ag ions was found to be 0.5% molar ratio
Tuning the dielectric properties of CaCu3Ti4O12 ceramic by Cu2O addition and microstructural modifications
(Elsevier, 2023) Djafar, Rabah; Boumchedda, K.; Fasquelle, D.; Chaouchi, A.; Sedda, K.; Bououdina, M.; Bellucci, S.
Cuprous (I) oxide (Cu2O) was used instead of Cupric (II) oxide (CuO) for the synthesis of CCTO ceramic by solid-state reaction. The impact of sintering time on the structure stability, grain size, and dielectric performance of Cu2O-based CCTO ceramics was discussed. XRD analysis indicates that the CaCu3Ti4O12 cubic phase was successfully synthetized. The studied samples manifested high permittivity and quite low dielectric loss values in the frequency range (20–106 Hz); with optimum values of 15,423 and 0.083 respectively achieved after sintering at 1050 °C for 14 h while for longer sintering times of 19 h and 24 h resulted in higher values of permittivity of 19,943 and 21,392 respectively were obtained and associated with an improved loss tangent of ∼0.114 and 0.127, respectively. It was found that a longer sintering time of Cu2O-based CCTO ceramics resulted in an important improvement of the dielectric properties
Tuning the optical properties and photocatalytic activity of Ti0.96 Nd0.02 O2 by Cd/Fe co-doping
(Springer, 2022) Mustafa, A.; Bensouici, F.; Bououdina, M.; Al-Najar, B.; Souier, T.; Belache, B.
This research work aims to investigate Fe/Nd and Cd/Nd co-doped TiO 2 thin films prepared by sol–gel and deposited by dip-coating onto soda-lime glass and the impact of these dopants on the photocatalytic properties. The structural, optical, morphological, and photocatalytic properties of all the prepared sam- ples have been characterized by X-ray diffraction, atomic force microscope, UV– Vis spectroscopy (UV–Vis), and photoluminescence spectroscopy. Rietveld analysis of XRD patterns indicates that TiO 2 co-doping by Fe/Nd and Cd/Nd deteriorates the crystallinity of the pure anatase phase whereas the crystallite size seems not affected, i.e., 13 nm. The morphology of the surface has been affected; the roughness increases from 0.91 nm for pure TiO 2 to 2.73 nm for Cd/ Nd co-doped TiO 2 . UV–vis spectroscopy and photoluminescence analyses indicate that the band-gap energy decreases with co-doping from 3.33 eV for TiO 2 up to 3.26 eV for Fe-Nd/TiO 2 . The degradation of methyl blue tests manifests that pure TiO 2 exhibits higher efficiency of 89% dye in three hours only. Significant decrease in the photocatalytic activity upon co-doping has been observed and a mechanism based on the combined effect of doping, annealing, and substrate effect is proposed to explain the photodegradation behavior