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Item Electrochemical Deposition of PANI/PEDOT:PSA. A. S Composite Polymer for Supercapacitors Application(Springer Nature, 2024) Loucif Seiad, M.; Meziane, L.; Boudieb, N.; Kahlouche, K.; Nait Bouda, A.; Ratni, I.; Benammane, I.Supercapacitors have attracted a great deal of interest in energy storage due to their high power density and exceptionally long cycle life. Conductive polymers, such as polyaniline (PANI) and poly (3,4-ehtylenedioxythiophene) (PEDOT), are among the most studied electroactive materials due to their excellent properties. In the present study, PANI and PANI/PEDOT:PSS composites were synthesized electrochemically for supercapacitor applications. Characterization techniques, such as X-ray diffraction, indicate the amorphous nature of PANI and PANI/PEDOT:PSS composites. UV-Vis spectroscopy was used to analyze the optical properties of PANI and PANI/PEDOT:PSS composite. The morphology of the PANI/PEDOT:PSS composite observed by scanning electron microscopy (SEM) shows the morphology of the porous structure, which enhances charge transport in the supercapacitor. The electrochemical performance of both materials was obtained in a 0.5 M H2SO4 electrolyte. The cyclic voltammetry study of the PANI/PEDOT:PSS composite showed the highest specific capacitance of 1265.38 F/g at a scan rate of 20 mV compared with PANI, which recorded a value of 1020 F/g at 10 mV/s. Electrochemical impedance spectroscopy with an appropriate equivalent circuit model was employed to explore the internal resistance and capacity observed for PANI and PANI/PEDOT:PSS. Electrochemical and physicochemical characterization tests showed that the composite exhibited superior electrical and structural performance, making it a suitable material for energy storage applications.Item Physical properties of the perovskite SrTiO3−δ synthetized by chemical route(Springer, 2023) Merrad, S.; Abbas, M.; Brahimi, R.; Bellal, B.; Trari, M.The perovskite SrTiO3−δ elaborated by chemical route was characterised by physical and electrochemical methods. The oxide crystallizes in a cubic structure with a lattice parameter of 3.907(5) Å and a crystallite dimension of 71 nm. The morphology visualized by the SEM-EDX analysis shows spherical grains with a mean size of 0.2 μm, formed by agglomeration of crystallites. The diffuse reflectance gave a gap (Eg) of 3.21 eV, ascribed to the charge transfer O2−: 2p → Ti4+: 3d. The thermal variation of the conductivity (σ) obeys an exponential law {σ = σoexp-0.27 eV/T} assigned to low hopping polarons. The electrochemical characterization was undertaken in Na2SO4 solution (10− 1 M) and the n-type character demonstrated from the capacitance measurement and cyclic voltammetry under UV-irradiation, is due to oxygen deficiency. A flat band potential (Efb) of − 0.31 VSCE was determined with a depletion width extended up to ~ 4 μm, advantageous for the formation of electron / hole (e− / h+) pairs. The electrochemical stability against photocorrosion was also shown from the semi-logarithmic plot (log J–E). As application, the Congo Red a diazo dye (CR) is successfully oxidized under UV light on SrTiO3−δ; an abatement of 63% was reached. According to the scavengers mechanism, hydroxyl •OH is the main specie responsible for the CR oxidation. The discoloration follows a pseudo-first-order kinetic with a half-life of 189 minItem Chlorophytum rhizosphere, a suitable environment for electroactive biofilm development(Springer, 2020) Tou, Insaf; Azri, Mounia; Sadi, Meriem; Zitouni, D.; Merad3, A. S.; Laichouchi, A.; Drouiche, N.; Lounici, H.; Gana-Kebbouche, S.The electroactivity of Chlorophytum rhizospheric soil using imposed potential chronoamperometry and a characteristic cyclic voltammetry was demonstrated in the present work. Five different polarizations were tested: − 0.3, − 0.155, 0, + 0.155, and + 0.3 V/SCE. The current density had stabilized around − 0.0068 mA/m2 and − 0.03 mA/m2 at − 0.155 and − 0.3 V/SCE, respectively. However, at 0, + 0.155, and + 0.3 V/SCE, a current density had reached respectively 1.46 A/m2, 1.48 A/m2, and 0.6 A/m2. The potential + 0.155 V/SCE seemed to better stimulate the electrogenic bacteria activity of the Chlorophytum rhizosphere. Different bacterial strains had formed electroactive biofilms in response to different electrode polarizations. The Chlorophytum rhizosphere electroactivity has depended on strict anaerobes as well as facultative anaerobic bacteria under anaerobic conditions. Furthermore, the Chlorophytum rhizosphere soil had closed almost equal proportions of Firmicutes and Proteobacteria whose electroactivity seemed to depend on the Proteobacetria more than the Firmicutes and had could be thereby a suitable environment for electroactive biofilm developmentItem Synthesis, DFT/TD-DFT theoretical studies, experimental characterization, electrochemical and antioxidant activity of Fe(III) complexes of bis (dimethylglyoximato) guanine(Elsevier, 2019) Abane-Merzouk, Lamia; Adkhis, Ahmed; Terrachet-Bouaziz, Souhila; Makhloufi-Chebli, MalikaA new series of Iron (III) complexes of general formula [Fe(Hdmg) 2 (Gua)X]nH 2 O where (Hdmg = dimethylglyoximato monoanion, Gua = Guanine, X = Cl, Br or I) have been prepared and characterized by elemental analysis, conductivity, infrared spectra and electronic spectra. The molar conductance data confirm that all the complexes are no electrolytic. The mode of bonding and geometry of the Fe(III) complexes have been inferred spectral data, an octahedral geometry is ascribed for all the Fe(III) complexes. In these compounds, two dimethylglyoximato monoanions bond to the metal in the equatorial plan have been formed. The two axial sites being occupied by the guanine and the halogen moieties. The thermal properties of the Fe(III) complexes were investigated using TG and TDA. The thermal behavior of the compounds illustrates the general decomposition patterns of the complexes. The voltammetry experiments have been performed on the complexes to evaluate the redox process of Fe(III)/Fe(II) couple. These compounds were screened for their in-vitro antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) free radical scavenging. The results obtained show that these complexes have a good antioxidant activity in comparison with ascorbic acid as positive controlItem 1,4-Dimethoxybutadienediyl-Bridged diiron compounds in three oxidation states : evaluation of delocalization effects(American Chemical Society, 2019) Sahnoune, Hiba; Mahias, Virginie; Halet, Jean-François; Lapinte, ClaudeThe binuclear iron complexes [Cp∗(PMe3)(CO)Fe-C(OCH3)=CH-CH=C(OCH3)-Fe(PMe3)(CO)Cp∗] (1meso and 1dl) were prepared by double deprotonation of their known parents [Cp∗(PMe3)(CO)Fe=C(OCH3)CH2-CH2-C(OCH3)=Fe(PMe3)(CO)Cp∗](PF6)2 (5meso and 5dl) and were isolated in good yield (90%). These complexes were characterized by ESI-mass spectrometry, IR and multinuclear NMR spectroscopy, and cyclic voltammetry. The singly and doubly oxidized forms 1meso(PF6)n and 1dl(PF6)n (n = 1, 2) were prepared by oxidation of the parent neutral complexes with 1 and 2 equiv of ferrocenium salt (93-100% yield). The related complex [Cp∗(dppe)Fe-C(OCH3)=CH-CH=C(OCH3)-Fe(dppe)Cp∗](PF6) (2(PF6)) was obtained by reduction of the known dicationic derivative [Cp∗(dppe)Fe-C(OCH3)=CH-CH=C(OCH3)-Fe(dppe)Cp∗](PF6) (2(PF6)2) with 1 equiv of cobaltocene (100% yield). Multinuclear NMR spectroscopy allowed us to establish the diiron(II) conjugated μ-bis(carbene) structure for 1meso(PF6)2 and 1dl(PF6)2. In the case of the meso derivative, 1H NMR revealed the presence of E and Z isomers in a 4:1 ratio, confirming the presence of a C=C double bond in the middle of the bridge. The three radicals 1meso(PF6), 1dl(PF6), and 2(PF6), which are thermally stable, were analyzed by IR, Mössbauer, ESR, UV-vis, and NIR spectroscopy. Experimental data, discussed with the support of quantum chemistry calculations performed at the DFT level of theory, indicate that these radical cations exhibit characteristics of oxidation on the butadienediyl bridge rather than on the metal centers