Ahmed Madani - Academia.edu (original) (raw)

Papers by Ahmed Madani

Bulletin of Materials Science

This work focuses on the electrochemical synthesis of polymer-inorganic semiconductor hybrid cons... more This work focuses on the electrochemical synthesis of polymer-inorganic semiconductor hybrid consisting of poly(3-hexylthiophene) (P3HT) and titania nanoparticles (TiO2). The P3HT–TiO2 hybrid was prepared by electropolymerization of the 3HT monomer in a dichloromethane-tetrabutylammonium perchlorate (CH2Cl2/TBAP) solution containing titania nanoparticles (TiO2). The hybrid material was electrodeposited on indium-tin oxide (ITO) substrates via cyclic voltammetry method. It was illustrated from scanning electron microscope observation that the incorporation of TiO2 nanoparticle within P3HT matrix created an interconnected network structure, which has improved interfacial transport charges. Furthermore, the potentiodynamic results revealed that the electropolymerization process of P3HT in the presence of TiO2 was easier and occurred at an early value of 1 V (vs. Ag/AgCl) with a noticeable increase in current density. The impedance results showed lower charge-transfer resistance and higher capacitance values for the P3HT–TiO2 hybrid (Rct = 7 Ω cm−2, CPE = 5.196 μF cm–2) compared to pure P3HT (Rct = 37 Ω cm−2, CPE = 1.959 μF cm–2), demonstrating the better conductivity and charge storage capacity for the P3HT–TiO2 hybrid.

Synthetic Metals, 2021

Abstract This work reports on the use of the sodium hexametaphosphate (SHMP) surfactant for the d... more Abstract This work reports on the use of the sodium hexametaphosphate (SHMP) surfactant for the dispersion of ZnO nanoparticles in the PPy polymer matrix for the production of the composite PPy-ZnO as an anticorrosive coating on mild steel. The coatings of PPy, PPy-ZnO and PPy-ZnO-SHMP were electrodeposited by cyclic voltammetry (CV) method. The anticorrosion behavior of all the coatings was studied in a 3.5% NaCl solution medium at room temperature. The performance of all the coatings was evaluated using polarization measurements, electrochemical impedance spectroscopy (EIS) and chronopotentiometry at open circuit potential (OCP). It was found that the presence of SHMP during synthesis resulted in a more homogeneous and compact coating in which the ZnO nanoparticles were more evenly distributed among the PPy particles. Furthermore the coating PPy-ZnO-SHMP exhibited higher corrosion resistance and provided better barrier properties compared to pure PPy and PPy-ZnO coatings.

IEEE Sensors Journal, 2019

104 MHz surface acoustic wave sensors, functionalized with two polypyrrole (PPy) imprinted polyme... more 104 MHz surface acoustic wave sensors, functionalized with two polypyrrole (PPy) imprinted polymers, were designed for lead ion detection in liquid media. The main difference between the two ionic imprinted polymers (IIP) is related to the nature of the chelating agent: L-Cysteine (L-Cys) for the former and acrylic acid (AA) for the latter. Performances of the IIPs based sensors were compared in terms of sensitivity, limits of detection (LOD), dissociation constants and selectivity. The gravimetric results indicated that both designed sensors can detect picomolar concentrations of lead ions. These values are, in fact, significantly inferior to the World Health Organization (WHO) maximum accepted limit in drinking water, and among the lowest LODs ever reported in the literature. The relevant dissociation constants, calculated from the most appropriate fits of the calibration curves, were estimated at: Kd<inline-formula> <tex-math notation="LaTeX">$_{\textsf {1}} = (\textsf {1.1} \pm \textsf {0.4})\times \textsf {10}^{-\textsf {10}}$ </tex-math></inline-formula> M and Kd<inline-formula> <tex-math notation="LaTeX">$_{\textsf {2}}= (\textsf {1.1} \pm \textsf {0.8})\times \textsf {10}^{-\textsf {5}}$ </tex-math></inline-formula> M for L-Cys-IIP/Pb<sup>2+</sup> and Kd<inline-formula> <tex-math notation="LaTeX">$_{\textsf {1}}= (\textsf {1.1} \pm \textsf {0.3})\times \textsf {10}^{-\textsf {13}}$ </tex-math></inline-formula> M and Kd<inline-formula> <tex-math notation="LaTeX">$_{\textsf {2}}= (\textsf {5.9} \pm \textsf {1.8}) \times \textsf {10}^{-\textsf {10}}$ </tex-math></inline-formula> M for AA-PPy-IIP/ Pb<sup>2+</sup>, thus confirming the strong binding between the designed IIPs and lead ions. Selectivity tests were investigated with mercury, cadmium, copper, zinc, and nickel divalent ions, which largely coexist with lead ions in soils, rivers, and wastewaters.

Ionics, 2015

ABSTRACT Poly(3-methylthiophene)-cadmium selenide (PMeT-CdSe)-modified electrode was galvanostati... more ABSTRACT Poly(3-methylthiophene)-cadmium selenide (PMeT-CdSe)-modified electrode was galvanostatically prepared in CH3CN/LiClO4 in the presence of 3-methylthiophene and nanoparticles of CdSe. The synthesized composites were characterized by the UV-vis spectroscopy, scanning electronic microscopy, Fourier Transform infrared spectroscopy (FTIR) and energy-dispersive X-ray (EDX) techniques. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behaviour of the resulting materials. This study showed that the presence of CdSe nanoparticles in the poly(3-methylthiophene) film improves the optical properties of PMeT via a simple preparation method and shows that these films could be used in photoelectrochemical applications such as the photovoltaic cells.

Thin Solid Films, 2011

A polyterthiophene-titanium oxide (P3T + TiO 2) composite material was electrochemically synthesi... more A polyterthiophene-titanium oxide (P3T + TiO 2) composite material was electrochemically synthesized in dichloromethane-tetrabutylammonium perchlorate CH 2 Cl 2 / TBAP containing a monomer (terthiophene) and semiconductor (TiO 2) nanoparticles. The obtained material was characterized using electrochemical methods (cyclic voltammetry and electrochemical impedance spectroscopy) and spectrometry analysis [scanning electron microscopy (SEM), spectrophotometer ultraviolet (UV)-visible, energy dispersive X-ray spectroscopy (EDX) and force atomic microscopy (AFM)]. The effect of TiO 2 nanoparticles on the photoelectrochemical and optical characteristics of P3T composite films was also studied. The results confirmed the presence of TiO 2 nanoparticles in the polyterthiophene matrix. The surface morphology of the (P3T + TiO 2) composite films revealed that adding TiO 2 nanoparticles increase the film's roughness values. The addition of TiO 2 nanoparticles improve the absorbance of P3T composite films. Moreover, the photocurrent of the composite increased with the TiO 2 nanoparticles concentration and showed that this composite material could be used in photoelectrochemical applications such as photovoltaic cells.

Surface and Interface Analysis, 2010