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A solid polymer electrolyte with a polyvinyl alcohol (PVA) matrix and a mixture of ethylene glycol (EG) and phosphoric acid as proton conductor has been developed. These complexes have been studied by X-ray diffraction (XRD), infrared Fourier transform spectrometry (FTIR) and electrochemical impedance spectrometry (EIS). The optimum ionic conductivity value of the ternary PVA-EG(45 wt%)-H3PO4(5 wt%) complex film has been achieved to be 5.2 10−3 S cm−1 at RH = 100% with adequate mechanical properties (especially flexibility) and with a low activation energy of 9 kJ mol−1. Due to its good electrical and mechanical properties, this material has been successfully used as solid state proton electrolyte in Zn/MnO2 cell delivering a capacity of 220 Ah kg−1 and an energy density of up to 286 Wh kg−1.

Organobentonite adsorbents were prepared by treating raw bentonite (RB) with three different cetyltrimethylammonium bromide concentrations (0.5, 1 and 2CEC). The prepared adsorbents were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Thermogravimetric analysis (TGA) and Specific surface area (BET). The adsorbents were then tested for their ability to remove diclofenac (DIC) and ibuprofen (IBU) from aqueous solution at different conditions (pH, adsorbent dosage, initial drug concentration, and contact time) in order to determine the optimum conditions for adsorption. The kinetics in single drug solution follows pseudo-second order kinetic model. The adsorption isotherms of the two drugs obeyed both the Langmuir and Freundlich isotherm models with the saturation adsorption amount onto 2CECRB of 600.6 and 194.9 mg/g for DIC and IBU, respectively. In adsorption from mixed drug solutions, DIC and IBU show competitive adsorption. Hydrophobic interactions play an important role during the sorption process. In addition, 2CECRB could be regenerated and reused after four cycles.

In this paper, we report on the electrochemical behavior of zinc (Zn) anode in Zn–MnO2 battery tested in aqueous NH4Cl electrolyte with a concentration ranging from 0.01 to 1 M without any additives. The Zn electrode shows the lowest corrosion behavior for the 0.1 M concentration. Such corrosion decrease was attributed to a shielding effect due to the formation of a corrosion layer expressed by a higher charge transfer resistance (Rct) of 270 Ω. The X-ray diffraction (XRD) analysis shows that it constitutes by ZnO, Zn(OH)2 and Zn(NH3)2Cl2. The Zn was successfully assembled with MnO2 to form a Zn/MnO2 cell using 0.1 M NH4Cl electrolyte. Two types of MnO2 powders were experimented as cathode namely nanostructured MnO2 (NMD) and commercial MnO2 (EMD). It was found that NMD gives the best performance in terms of output voltage and specific energy. Indeed, the Zn/NMD cell has a voltage of 1.743 V which is higher than that of Zn/EMD (1.674 V) at a current of 1 mA. It was found that the cells voltage decreased after 4 h of continuous discharge to 1.712 V and 1.660 V, respectively. Moreover, the Zn/NMD cell can reach a highest specific energy of 228.30 mWh/g. Therefore, our Zn/NMD cell can be used for a high-performance primary battery and take over Zn/MnO2 battery market.

A Nickel Schiff base complex, insoluble in water, was synthesized and used as modifier. A Nickel Schiff base modified carbon paste electrode MCPE was build. The electrodes were characterized by scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDXS), cyclic voltammetry and chronoamperometry. The modifier is elctroactive, a well defined redox couple of Ni/Ni in alkaline medium was made in evidence. It presents a quasi-reversible system with electron transfer coefficient (0.38) and electron transfer rate of 4.5 s. The electrogenerated Ni species on the surface of the electrode act as an excellent catalyst toward thiosulfate oxidation reaction with a chemical rate constant K equal to 23,6 Ms. The different techniques involved in this study qualify our modified electrode as sensitive, reliable and very stable for thiosulfate analysis., We gratefully aknowledge the ‘‘Direction Ge´ne´rale de Recherche (DGR)” for the financial support. The authors would like also to thank Professor Ali Ourari, from Faculte´ de Technologie, Universite´ Ferhat Abbas-Se´ tif-1, Laboratoire d’Electrochimie, d’Inge´nierie Mole´culaire et de Catalyse Redox (LEIMCR), Se´ tif 19000, Algeria, for his help.

The nanostructured MnO2 powder was successfully synthesized by electrodeposition on stainless steel (SS) substrate from hot 0.3 M MnSO4·H2O aqueous solution with pH value adjusted to 2. The electrochemical behavior of synthesized MnO2 was compared to that of the commercial electrolytic manganese dioxide (EMD). The investigation was conducted using a new cell which is manufactured in our laboratory. This gave us the possibility to present a new contribution and an improvement in the study of MnO2 electrochemical behavior. The analysis of the synthesized MnO2 and EMD powders by different techniques: FEG-SEM, EDS, TEM, XRD, and BET revealed the presence of electrodeposited nanostructured γ-MnO2 with high specific surface area of 139.59 m2 g−1 for the nanostructured MnO2 and 46.60 m2 g−1 for EMD. The electrochemical study of these powders conducted by linear voltammetry, electrochemical impedance spectroscopy (EIS) measurements, and Zn/MnO2 battery tests in 0.1 M NH4Cl electrolyte showed that the performance of the synthesized nanostructured MnO2 powder was higher than that of the commercial EMD powder.

In this work, manganese metal and its nanostructured dioxide (MnO2) were applied as electrodes for the development of a new Mn/MnO2 battery. The MnO2 was deposited onto platinum substrate using electrodeposition technique and collected as powder cathode in the new battery. The influences of temperature and precursor pH on the MnO2 film properties were investigated. Scanning electron microscopy, X-ray diffraction (XRD), energy dispersive X-ray analysis and transmission electron microscopy (TEM) were used to characterize the MnO2 deposit. The XRD and TEM demonstrate that the MnO2 was deposited in its γ-MnO2 phase with a particle size less than 15 nm. In addition, the pH solution plays a key role in the electrochemical performance of the MnO2 as a cathode. Indeed, the γ-MnO2 deposited at pH = 2 provides a high discharge performance in KOH and NH4Cl aqueous electrolytes. This led to a new Mn/MnO2 cell with better performance compared to the classical Zn/MnO2 cell in terms of discharge in NH4Cl electrolyte. During the discharge process, co-insertion of Mn2+ and H+ promotes the transformation of MnO2 into MnxMnO4, MnOOH, and Mn2O3. In addition, the Mn/MnO2 cells exhibits a high output voltage >2 V in NH4Cl. It reach a high voltage at around 1.89 V after 3 h of continuous discharge. The cells can achieve a discharge capacity of 1000 mA h.g−1 at a current density of 330 mA g−1 with the highest specific energy of 1890 mWh.g−1. Moreover, Mn/MnO2 cells are more stable in NH4Cl electrolyte which exhibits a voltage drop of 6% after 3 h of continuous discharge. Such results demonstrate that the assembled Mn/MnO2 battery can occupy an important place in the energy storage field as a low cost and high performance device.

To obtain new materials, we modified Algerian halloysite by thermal activation (HalC), acid activation (HalA), combined thermal-acid activation (HalCA) and acid-thermal activation. X-ray diffraction, Fourier Transform infrared and BET textural analysis were used to characterize changes. After the HalC of halloysite at 600°C, no XRD peaks were shown and a total disappearance of the absorption bands ranging from 3,700 to 3,600 cm−1. The treatment of halloysite by sulphuric acid increases the surface area from 185.4 to 321.0 m2/g. Halloysite is first calcined and then activated by acid, its surface area increases from 74.3 to 538.6 m2/g. The effect of initial pH, adsorbent dose, contact time and temperature on the removal of 2,4,5-trichlorophenol (TCP) by modified halloysite samples was investigated. Equilibrium data were fitted to the Langmuir, Freundlich and Toth models. The best fit of the cited models was the Freundlich model, which suggested infinite adsorption onto heterogeneous surface. The ps...