Research Center in Analytical Chemistry and Physics

Algiers, Algeria

Research Center in Analytical Chemistry and Physics

Algiers, Algeria
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Bouhamidi Y.,University of Science and Technology Houari Boumediene | Kaouah F.,University of Science and Technology Houari Boumediene | Nouri L.,University of Science and Technology Houari Boumediene | Nouri L.,Research Center in Analytical Chemistry and Physics | And 2 more authors.
International Journal of Environmental Science and Technology | Year: 2017

The adsorption behavior study of diethyl and dibutyl phthalates was investigated onto a new activated carbon prepared from an abundant biomass “Albizia julibrissin pods,” treated chemically by H3PO4. A series of experiments were conducted in a batch system to estimate the effect of operating conditions such as the adsorbent nature, the dose of adsorbent, the contact time, the initial concentration and the temperature on the adsorption efficiency. The optimum operating conditions were found to be 0.1 and 0.05 g of adsorbent for diethyl and dibutyl phthalates, respectively, at 30 min equilibrium time, 150 mg g−1 and 293 K. The adsorption isotherms for both phthalates were fit at different temperatures using the nonlinear regression of Langmuir, Freundlich, Dubinin–Radushkevich and Redlich–Peterson. The pseudo-first order, pseudo-second order by nonlinear regression and intraparticle diffusion models were used to describe the adsorption kinetic. The results show that the intraparticle diffusion model is not the limiting step governing the adsorption mechanism. The structural and textural characteristics of adsorbent surface were investigated. FTIR analysis of unloaded and phthalates-loaded adsorbent revealed that the aliphatic groups attached to phthalate esters are involved in adsorption mechanism. © 2016, Islamic Azad University (IAU).


Nadji N.,Annaba University | Nadji N.,Research Center in Analytical Chemistry and Physics | Belghiche R.,Annaba University | Merlet D.,University Paris - Sud
Desalination and Water Treatment | Year: 2017

An heteropolyanion compound consisting of saturated Dawson anions and trivalent iron cations, α2H3FeP2W17MoO62 has been synthesized and characterized by various spectroscopic methods, IR, UV-Vis, 31P NMR and ESI-MS. The catalytic performances of heteropolyanion were tested for degradation of aqueous Malachite Green dye under Fenton process. The degradation reaction was monitored by UV-visible and IR spectroscopy. The effects of different reaction parameters such as the initial pH of the medium, the initial hydrogen peroxide concentration, the catalyst mass, the initial MG concentration and the reaction temperature on the oxidative degradation of malachite green has been investigated. The optimal reacting conditions were found to be pH = 3, initial hydrogen peroxide was 0.31 M, and the catalyst mass was 0.03 g, for initial MG concentration of 20 mg.L-1 at 30°C. After optimizing operating parameters, the dye was demineralized after 7 h of reaction. © 2017 Desalination Publications. All rights reserved.


Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Boudjemaa A.,University of Science and Technology Houari Boumediene | Bachari K.,Research Center in Analytical Chemistry and Physics | Bachari K.,University of Science and Technology Houari Boumediene | Trari M.,University of Science and Technology Houari Boumediene
International Journal of Energy Research | Year: 2013

The iron hexagonal mesoporous silica (Fe-HMS)-n photocatalyst, where n is the molar ratio Si/Fe in the precursor gel (=50), has been successfully synthesized at an ambient temperature using hexadecylamine as template agent. The material was characterized by X-ray diffraction, N2 adsorption measurement Brunauer, Emmet, Taller (BET) and Barrett-Joyner-Halenda theory, UV-Vis spectroscopy, high-resolution transmission electron microscopy and electron spin resonance. The electrical conductivity follows an Arrhenius-type law with activation energy of 0.04eV. Fe2O3 is uniformly dispersed on the HMS surface; it works synergistically to make Fe-HMS photoelectrochemically active. The flat band potential (-0.75VSCE) is higher than the potential of hydrogen generation (-0.50VSCE at pH~7), and the material shows high efficiency for hydrogen evolution upon visible light. The photoactivity in Na2SO4 and Na2SO3 (0.1M) solution was found to be 136 and 175μmolg-1min-1, respectively under full light (29mWcm-2). The tendency to saturation, observed only in SO3 2- electrolyte, is ascribed to the competitive reduction of the end product, namely S2O6 2- with the water reduction. © 2011 John Wiley & Sons, Ltd.


Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Trari M.,University of Science and Technology Houari Boumediene | Bachari K.,Research Center in Analytical Chemistry and Physics
Environmental Progress and Sustainable Energy | Year: 2014

Iron-substituted mesoporous silica, Santa Barbara Amorphous (Fe-SBA-15) molecular sieve with Si/Fe ratio of 50 is prepared by microwave-hydrothermal method. The photoelectrochemistry reveals a metal deficiency and the oxide exhibits P type conductivity with activation energy of 20 meV. The flat band potential, determined from the capacitance measurements, is found to be -0.61 VSCE. Hence, the conduction band, made up of 3d orbital (∼4 eV), permits a good position of H2O/H2 level (-0.88 V/SCE), thus allowing a thermodynamically feasible H2 liberation under visible light. In neutral medium, the photocatalyst shows a high H2 evolution with a rate of 115 μmol g-1 min-1 in presence of SO3 2- as hole scavenger. The initial performance of the PEC system is restored when the solution is bubbled with nitrogen, a deactivation effect of <2% is observed. © 2013 American Institute of Chemical Engineers.


Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Bachari K.,Research Center in Analytical Chemistry and Physics | Trari M.,University of Science and Technology Houari Boumediene
Materials Science in Semiconductor Processing | Year: 2013

We describe in the present work the photo-electrochemical characterization of iron/folded-sheets mesoporous materials (Fe-FSM-16, Si/Fe=60) synthesized by microwave-assisted hydrothermal (M-H) method and its application for the hydrogen evolution upon visible light. The mesoporous catalyst consists of small Fe2O3 particles (∼2 nm) spread on SiO2 with specific surface area of ∼800 m2 g-1. The capacitance measurements reveal an iron deficiency and the oxide exhibit p type conductivity with activation energy of 0.07 eV. The optical gap of the hematite (α-Fe2O3) is evaluated at 3.24 eV from the diffuse reflectance spectrum. The flat band potential Vfb (-0.54 V SCE) and the holes density ND (9.56×1014 cm-3) of the hematite are obtained respectively by extrapolating the linear part to C-2=0 and the slope of the Mott Schottky plot. At pH=7, the conduction band (-0.47 VSCE) is suitably positioned with respect to the H2O/H2 level (-0.59 VSCE) leading to a spontaneous water reduction. The oxide is stabilized by hole consumption involving SO32- and S2O 32- species and spectacular improvement of the hydrogen evolution is reported with evolution rates of ∼461 and 163 μ mol respectively. © 2013 Elsevier Ltd. All rights reserved.


Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Mokrani T.,University of South Africa | Bachari K.,Research Center in Analytical Chemistry and Physics | Coville N.J.,University of Witwatersrand
Materials Science in Semiconductor Processing | Year: 2014

A noncatalytic chemical vapor deposition method was used to prepare graphitized carbon spheres (CSs) from acetylene. The CSs (diameter of 115±10 nm) with n type conductivity were found to be photo-electrochemically active with a diffuse reflectance spectrum band gap of 1.01 eV. The electrical conductivity followed an Arrhenius type law with an activation energy of 0.53 eV. From the capacitance measurements, the flat band potential (Vfb=-0.75VSCE) and the electron density (ND=3.46×1015 cm-3) were determined. © 2014 Elsevier Ltd. All rights reserved.


Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Rebahi A.,University of Witwatersrand | Terfassa B.,University of Witwatersrand | Chebout R.,Research Center in Analytical Chemistry and Physics | And 3 more authors.
Solar Energy Materials and Solar Cells | Year: 2015

A new photo-catalyst based on Fe2O3 supported on carbon spheres (CSs) to improve the charge transport property of Fe2O3 in the photo-reduction of water under light irradiation is reported. The CSs (d ~560 nm) were prepared by a non-catalytic CVD method from C2H2 and characterized by XRD, UV–visible and FTIR spectroscopy, chemical analysis and TEM. Fe (10%) was added onto the CSs using a deposition precipitation method. The Fe–CS material exhibited a band gap of 1.17 eV and a hydrogen evolution rate ~370 mol/g s in Na2SO4 electrolyte (pH ~7). This is an improved photo-activity, relative to Fe2O3 mixed with CSs (179 mol/g s), Fe2O3 (147 mol/g s) and CSs (281 mol/g s) and the enhanced activity is attributed to the light absorption behavior of the carbon spheres, the Fe2O3 as well as the intimate contact between Fe2O3 and the CSs. © 2015 Elsevier B.V.


Bouzit H.,8 May 1945 University of Guelma | Bouzit H.,Research Center in Analytical Chemistry and Physics | Stiti M.,8 May 1945 University of Guelma | Abdaoui M.,8 May 1945 University of Guelma
Journal of Inclusion Phenomena and Macrocyclic Chemistry | Year: 2016

Spectroscopic investigation supported by molecular modeling methods has been used to describe the inclusion complex of β-cyclodextrin (β-CD) with N-[(4-sulfonamidophenyl) ethyl]-5-(1,2-dithiolan-3-yl) pentanamide in solution and in solid state. By using UV–Vis absorption, the stoichiometric ratio of the complex was found to be 1:1 and the stability constant was evaluated as 1.3415.104 (mol/L)−1. Solid state characterization by FT-IR spectroscopy provided remarkable evidences of the formation of inclusion system. Moreover, semi-empirical calculations using PM3 level of theory and hybrid method ONIOM2 clearly indicate that the formed complexes are energetically favored in vacuum and in solution. From NBO analysis, the mutual interactions between β-CD and SULPA were analyzed and discussed. © 2016, Springer Science+Business Media Dordrecht.


Kebir M.,Research Center in Analytical Chemistry and Physics | Boudjemaa A.,Research Center in Analytical Chemistry and Physics | Bachari K.,Research Center in Analytical Chemistry and Physics
Materials Science in Semiconductor Processing | Year: 2015

The present work focused on the degradation of benzoic acid in aqueous solutions using the heterosystem NiCo2O4/ZnO as a semi-conductor. The material NiCo2O4 is prepared by a nitrate method and characterized by several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), reflectance diffuse (RD), electrical conductivity and the photo-electrochemical (PEC) characterizations. Under visible light, the benzoic acid degradation using a heterosystem NiCo2O4/ZnO is investigated. Several parameters are examined as the pH, the heterosystem ratio and the initial benzoic acid concentration. The results reveal that, as pH value increased from 2 to 6, the photo-degradation raised and the removal efficiencies attend the value 71%. The optimum results exhibited an enhancement photo-activity at a neutral pH and with a heterosystem ratio 50/50. The high efficiency is due to the present of unique structure constructed which increases the amount of electro-active sites and facilitates the electrolyte penetration via the electron transfer. Thus, the kinetic analysis showed that the photo-degradation rates can be approximated to be pseudo-first order, according to the Langmuir-Hinshelwood kinetics model. © 2015 Elsevier Ltd.All rights reserved.


Rouaiguia-Bouakkaz S.,8 May 1945 University of Guelma | Benayahoum A.,8 May 1945 University of Guelma | Benayahoum A.,Research Center in Analytical Chemistry and Physics
Journal of Physical Organic Chemistry | Year: 2015

In this work, the relationship between the structure and the radical scavenging activity of seven hydroxycoumarins and their sulfured analogs was investigated for the first time by density functional theory calculation in the gas phase, benzene, and water. Our investigation includes hydrogen atom transfer, single-electron transfer-proton transfer, and sequential proton loss electron transfer mechanisms. The results revealed that the bond dissociation enthalpy values of sulfured coumarins were lower than those of hydroxylated analogs. The obtained results were in a good agreement with the experimental results. The hydrogen atom transfer mechanism is dominant in both benzene and vacuum. The sequential proton loss electron transfer mechanism represents the most thermodynamically preferred reaction pathway in water. However, single-electron transfer-proton transfer mechanism is not the most preferred one in all media. Finally, this work contributes to the understanding of the pharmacological activity of the compounds studied. Copyright © 2015 John Wiley & Sons, Ltd.

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