Recent progress in nanocomposites based on conducting polymer: application as electrochemical sensors

Abstract Over the years, intensive research works have been devoted to conducting polymers due to their potential application in many fields such as fuel cell, sensors, and capacitors. To improve the properties of these compounds, several new approaches have been developed which consist in combining conducting polymers and nanoparticles. Then, this review intends to give a clear overview on nanocomposites based on conducting polymers, synthesis, characterization, and their application as electrochemical sensors. For this, the paper is divided into two parts: the first part will highlight the nanocomposites synthesized by combination of carbon nanomaterials (CNMs) and conducting polymers. The preparation of polymer/CNMs such as graphene and carbon nanotube modified electrode is presented coupled with relevant applications. The second part consists of a review of nanocomposites synthesized by combination of metal nanoparticles and conducting polymers

Proprietes electrochimiques de la polyaniline en presence d'une reaction de mediation. Etude en fonction du ph par impedances ac et ehd et microbalance a quartz.

We studied by impedance ac and ehd the oxidation of ferrocyanide on an electrode modified by polyaniline. During our study, we demonstrated a low-frequency relaxation effect of ph 2.5. The study of this phenomenon according to several experimental parameters, such as the potential, the rotation speed of the electrode, the redox substrate concentration and the thickness of the film allowed us to establish a relationship between this phenomenon and the protonation equilibrium of the imine form of emeraldine whose pk is about 3 according to the data of the literature. We have verified that this phenomenon disappears completely by replacing polyaniline with poly-n-methylaniline.Nous avons etudie par impedance ac et ehd l'oxydation du ferrocyanure sur une electrode modifiee par la polyaniline. Nous avons mis en evidence, lors de notre etude, un effet de relaxation basse frequence visible des ph 2,5. L'etude de ce phenomene en fonction de plusieurs parametres experimentaux, tels que le potentiel, la vitesse de rotation de l'electrode, la concentration en substrat redox et l'epaisseur du film nous a permis d'etablir une relation entre ce phenomene et l'equilibre de protonation de la forme imine de l'emeraldine dont le pk se trouve etre de l'ordre de 3 d'apres les donnees de la litterature. Nous avons verifie que ce phenomene disparait completement en remplacant la polyaniline par la poly-n-methylaniline

Les polymères conducteurs

Les polymères conducteurs ont ouvert grâce à leurs propriétés physico-chimiques et électrochimiques très intéressantes, de nouvelles perspectives dans le domaine des matériaux et dans celui des électrodes modifiées. Grâce à leurs propriétés mécaniques extraordinaires, leur résistance à la corrosion, leur faible coût, les polymères ont pu compléter les matériaux métalliques. Ils peuvent être synthétisés par voie chimique ou électrochimique et sont utilisés dans différents domaines de la vie quotidienne allant de l’objet le plus simple aux secteurs les plus pointus

Preparation of novel nanocomposite consisting of bismuth particles, polypyrrole and multi-walled carbon nanotubes for simultaneous voltammetric determination of cadmium(II) and lead(II)

International audienceA carbon paste electrode (CPE) modified with a nanocomposite consisting on functionalized multiwalled carbon nanotubes, polypyrrole film (PPy) and bismuth particles is described for simultaneous determination of Pb(II) and Cd(II). The structural and surface properties of the functionalized multiwalled carbon nanotubes and the nanocomposite were investigated by Fourier transform infrared spectroscopy and field-emission gun scanning electron microscopy. The electrical properties were studied by cyclic voltammetry and electrochemical impedance spectroscopy. The modified CPE was applied to the determination of Pb(II) and Cd(II) using square wave anodic stripping voltammetry. Under optimized conditions, the calibration plot is linear in the range from 0.11 to 120 μg L−1 for Pb(II) and 0.16 to 120 μg L−1 for Cd(II), the detection limits are 99 and 157 ng L−1, respectively. The sensor was applied to analysis of Pb(II) and Cd(II) in spiked real samples of tap water and gave satisfactory results

Electrochemical behaviour and voltammetric determination of p-phenylenediamine at carbon paste electrode

An electrochemical method was developed for voltammetric determination of p-phenyl-enediamine using a carbon paste electrode (CPE). The electrode exhibited the highest electrocatalytic activity toward oxidation and reduction of p-phenylenediamine in the phosphate buffer, pH 7. After optimizing the experimental conditions and square wave voltammetry parameters, a linear current response toward concentration of p-phenylenediamine was obtained in the range of 0.12–3.00 μM with detection limit of 0.071 μM. The proposed procedure was successfully applied for determination of the total p-phenylenediamine content in the takeout extract sample

Ionic liquid/carbon nanofibers/bismuth particles novel hybrid nanocomposite for voltammetric sensing of heavy metals

International audienceA novel electrochemical sensor based on a nanocomposite of ionic liquid 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [EMIM][NTf2], carbon nanofibres, and bismuth particles modified carbon paste (BiPs-CNFs/[EMIM][NTf2]/CPE) has been proposed. Though the large active surface area and good electrical conductivity, the elaborated sensor exhibited excellent electroanalytical performances for the detection of heavy metal ions. In the presence of bismuth ions deposited by in-situ modification, the sensitivity of the BiPs-CNFs/[EMIM][NTf2]/CPE for the determination of Pb2+ and Cd2+ were significantly enhanced. At a concentration ranging from 2 to 120 μg L−1 and under the optimal working conditions the limits of detection for Pb2+ and Cd2+ were 0.12 and 0.25 μg L−1, respectively. The proposed electrochemical sensor has a good repeatability, reproducibility and selectivity for detection of Pb2+ and Cd2+ even in the presence of interfering ions. The BiPs-CNFs/[EMIM][NTf2]/CPE has been successfully applied for the detection of heavy metals in a real sample of well water with satisfactory results

Synthesis of carbon nanofibers/poly(para-phenylenediamine)/nickel particles nanocomposite for enhanced methanol electrooxidation

International audienceSeveral studies have been conducted on direct methanol fuel cells (DMFCs) to resolve major issues such as the high cost of the catalyst and the poisoning of the electrode. Herein, a low-cost catalyst based on nickel particles (NiPs), carbon nanofibers (CNF) and poly(para-phenylenediamine) (PpPD) was carried out using a simple electrochemical method. The morphology and structure of the nanocomposite electrodes are characterized by field-emission gun scanning electron microscopy coupled with an energy dispersive X-ray detector, X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy. The effects of various parameters such as the PpPD film thickness and the NiPs content on the electrocatalytic performance of CPE/CNF/PpPD/NiPs are evaluated which lead to the optimized composition. The results of the methanol electrooxidation reaction at room temperature showed that the optimized CPE/CNF/PpPD/NiPs nanocomposite exhibits a high catalytic activity (Ip = 38.11 mA cm−2), good stability and durability for more than 6 h in comparison with CPE/CNF/NiPs. These findings truly highlight the synergetic effect of CNF/PpPD in enhancing the electrochemical activity and stability and the vast potential of CPE/CNF/PpPD/NiPs as low-cost catalyst and electrodes for DMFCs

Correlation between the interfacial ion dynamics and charge storage properties of poly(ortho-phenylenediamine) electrodes exhibiting high cycling stability.

International audienceAn integrated electrogravimetric study based on electrochemical quartz crystal microbalance (EQCM) unravels the interfacial ion transfer phenomena of the poly(ortho-phenylenediamine) (PoPD) thin film electrodes. Through a methodology coupling QCM with electrochemical impedance spectroscopy (ac-electrogravimetry), our work indicates that charge compensation process of PoPD in aqueous electrolytes (in acidified NaCl) occurs with the participation of multiple species, each playing a role at different temporal scales. The PoPD films are tested in a 2 electrode Swagelok cell in which Zn is used as both reference and counter electrodes and exhibit excellent stability over 8000 cycles with a relatively high specific capacitance of about 110 F g−1 at 30 C (0.63 mA cm−2) current density. The high rate capability and the excellent cycling stability of the PoPD electrodes are correlated to the electrolyte composition and the significant role of H+ to the charge compensation process is unravelled, which is made possible with coupled electrogravimetric methods of our study. By determining the interfacial flux dynamics and as well as the relative proportions of species transferred at the electrode/electrolyte interface, our results contribute to the understanding of the charge-discharge process of PoPD polymer, yet underexplored but emerging as a pseudo-capacitive electrode material