Volume 9 Number 1 March 2023

Studies on Electrochemical Properties of Polycarbazole Prepared Via Self-Support Polymerization and Self-Doping

Authors: S. K. Shakshooki ; F. A. El-Akari ; L. A. Abouderbala ; A. A. Alahemmer
Pages: 12-24
Mixed glassy zirconium-tin phosphate, g-Zr0.64.Sn.0.36(HPO4)2.3H2O(g-ZrSnP), nano fibrous cerium phosphate,   Ce(HPO4)2 2,9H2O(nCePf), and mixed glassy zirconium-tin phosphate / fibrous cerium phosphate nanocomposite membrane, [g-Zr0.64 Sn0.36 (HPO4)2]0.25 [Ce(HPO4)2]0.75 ..4.43H2O, were prepared and  characterized. By chemical ,  x-ray diffraction (XRD), thermogravimetric analysis (TGA), and  Fourier transform spectroscopy (FTIR), Zirconium  tin  mole ratio were estimated using (EDAX). Novel [g-Zr0.64 Sn0.36 (HPO4)2]0.25 [Ce(HPO4)2]0.75 / polycarbazole nanocomposite membrane was prepared via self-support polymerization of carbazole, which was promoted by the reduction of Ce(iv) phosphate present in the inorganic matrix.  Possible explanation is   nCePf present on the surface of the nanocomposite is attacked by carbazole, converted to cerium (III) orthophosphate(CePO4). The resultant polycarbazole was characterized by C,H,N analysis, SEM ,FT-IR.   UV-Vis and electrical conductance measurements. From elemental (C,H,N) analysis,  the amount of polycarbazole present in the  composite found to be (2.15 % in wt.). Polycarbazole is considered as one of modern material used in solar cells, furthermore it has become an important material for optoelectronic applications in recent years. The dc conductivity of polycarbazole nanocomposite membrane at 280C (using RC-Circuit) found to be equal to 3x10-5 Scm-1, range of semi-conductors. We suggest self-doping occurred on polymerization, which is due to H+ present in (O3POH)2 groups  of [g-Zr0.64 Sn0.36 (HPO4)2]0.25. The electrochemistry of resultant polycarbazole in acetonitrile solution for a range of concentrations from 1.06 x10-4 to 2.19 x 10–3 mol dm-3 was carried out using CV techniques. Investigation of its electrochemical properties affords insight into the mechanisms for their oxidation and reduction, therefore provides the basis for evaluating the stabilities of the material and for designing novel polycarbazole-derived materials with desired properties as well as new devices. That will be discussed.

Performance of Libyan Bentonite as Adsorbent for Methylene Blue Dye: Isotherms, Kinetics and Thermodynamic Studies

Authors: A. A. Jangher ; S. M. Aghila ; H. A. Jamhour,
Pages: 1-11
This study  provides an overview of natural and activated of Umm-Al- Razam, Libyan bentonite clay (north east of Libya region),  as an offered  adsorbent of anionic dye, methylene blue (MB) dye from aqueous solution; where the adsorption isotherms applied experimentally to investigate the effect of adsorbent dosage in a batch mode range from (0.1-1.2g), pH (1,3,5,7,9 and11), initial MB concentration (5,10,20,30,40 and 50ppm), temperature (25,35,45 and 55oC) and contact time range from (5 - 120min).The Characterization of natural Libyan bentonite (NLBn) and activated Libyan bentonite (ALBn)) was carried out firstly by infrared spectroscopy (FT-IR), electronic scanning microscopy(SEM) and X-ray diffraction (XRD) technique. The data analyzed by different models (Langmuir, Freundlich and Temkin) to describe the equilibrium isotherms and thermodynamic parameters such as Gibbs free energy change (ΔG) The data analyzed by different models (Langmuir, Freundlich and Temkin) to describe the equilibrium isotherms and thermodynamic parameters such as Gibbs free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) of the system were calculated. The results showed the equilibrium adsorption data of (NLBn) was fit better the Langmuir adsorption model but for (ALBn) was fit better to Temkin. The adsorption capacity for the removal of MB was 4.3 mg/g and 4.9 mg/g at different concentration on (NLBn) and (ALBn) respectively. Kinetics of dye removal was investigated and found to follow pseudo second order rate constant. The sorption and desorption capacity of MB was found to be 95% and 99% by both (NLBn and ALBn) respectively.