Synthesis, characterization, and applications of a novel poly(4-[pyrrol-1-yl methyl]benzoic acid)–silver composite

Vinitha M., Velraj G.

Polypyrrole (PPy) has higher conductivity than other conducting polymers. As the cost is lower than carbon-based electrodes, PPy is the commonly used polymer. Synthesized pure PPy and doped n-Ag2OPPy were characterized by instrumentation techniques such as Fourier Transform-Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) with Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UltraViolet Visible spectroscopy (UV–Vis). Further, electrical properties were determined from A.C. Electrical conductivity measurements by two-probe methods. FT-IR spectra confirm the presence of the nano silver oxide-doped polypyrrole. Polypyrrole composite shows a crystalline structure identified by XRD analysis with a crystalline size of 46.15 nm. EDX analysis confirms the presence of Ag & O in n-Ag2OPPy and SEM studies show the non-uniform distribution of Ag in n-Ag2OPPy. The optical property was studied by UV–Vis Spectroscopy. A.C Electrical conductivity of nano silver oxide-doped PPy was enhanced by two orders than pure PPy. The increase in A.C electrical conductivity is due to the additional effect of conductivity from the interfacial capacitive region. The specific capacitance for n-Ag2OPPy was calculated by Cyclic voltammetry (CV) which is found to be 293 Fg−1.

Lv J., Liu Z., Zhang L., Li K., Zhang S., Xu H., Mao Z., Zhang H., Chen J., Pan G.

• A multifunctional e-textile based on PPy@KCSF and PPy/Ag@KCSF is constructed. • PPy/Ag@KCSF-based sensor effectively balances the operating range and sensitivity. • PPy@KCSF-based supercapacitor shows prominent energy density and power density. • The multifunctional e-textile exhibits broad prospects in wearable domain. Textile-based wearable devices have attracted much attention as they can improve the wearing comfort and safety of electronic products. This paper proposes a fabrication strategy for a multifunctional e-textile based on polypyrrole (PPy) and rose-like silver flower-decorated knitted cotton/spandex fabric (KCSF). The rose-like silver flower grown on the PPy surface by electrodeposition can further improve the surface roughness and pressure sensitivity of the fabric. PPy and rose-like silver flower-decorated KCSF can be used to construct a multi-layer pressure/strain sensor. The as-obtained sensor not only exhibits an ultra-wide working pressure range (0–900 kPa), but also achieves a high sensitivity (17.41 kPa −1 for low-pressure areas), which effectively balances the operating range and sensitivity. More importantly, the sensor can be used to accurately monitor different physiological signals, including the levels of swallowing, breathing rate, voice recognition, and sleep quality. In addition, an all-solid-state supercapacitor is fabricated using PPy-coated fabric electrodes, demonstrating a high areal capacitance of 978.9 mF cm −2 at 1 mA cm −2 , an energy density of 80.3 µWh cm −2 , and power density of 0.38 mW cm −2 . The multifunctional e-textile with excellent sensing and energy storage behaviors is simple and easy to manufacture, with potential application prospects in the broad field of wearable technology.

Wang S., Zhang J., Gharbi O., Vivier V., Gao M., Orazem M.E.

Electrochemical impedance spectroscopy (EIS) is a powerful tool to investigate properties of materials and electrode reactions. This Primer provides a guide to the use of EIS and a comparison with other electrochemical techniques. The analysis of impedance data for reduction of ferricyanide in a KCl supporting electrolyte is used to demonstrate the error structure for impedance measurements, the use of measurement and process models, and the sensitivity of impedance to the evolution of electrode properties. This Primer provides guidelines for experimental design, discusses the relevance of accuracy contour plots to wiring and instrumentation selection, and emphasizes the importance of the Kramers–Kronig relations to data validation and analysis. Applications of EIS to battery performance, metal and alloy corrosion, and electrochemical biosensors are highlighted. Electrochemical impedance measurements depend on both the mechanism under investigation and extrinsic parameters, such as the electrode geometry. Experimental complications are discussed, including the influence of non-stationary behaviour at low frequencies and the need for reference electrodes. Finally, emerging trends in experimental and interpretation approaches are also described. This Primer on electrochemical impedance spectroscopy (EIS) provides an experimental design guide to measure impedance and how these data are analysed. The range of applications that require EIS, from measuring battery performance to electrochemical biosensors, is highlighted. Limitations of the method along with emerging trends in experimental optimizations and data interpretation are also described.

Shimoga G., Palem R.R., Choi D., Shin E., Ganesh P., Saratale G.D., Saratale R.G., Lee S., Kim S.

Metallic nanostructures (MNs) and metal-organic frameworks (MOFs) play a pivotal role by articulating their significance in high-performance supercapacitors along with conducting polymers (CPs). The interaction and synergistic pseudocapacitive effect of MNs with CPs have contributed to enhance the specific capacitance and cyclic stability. Among various conjugated heterocyclic CPs, polypyrrole (PPy) (prevalently knows as “synthetic metal”) is exclusively studied because of its excellent physicochemical properties, ease of preparation, flexibility in surface modifications, and unique molecular structure–property relationships. Numerous researchers attempted to improve the low electronic conductivity of MNs and MOFs, by incorporating conducting PPy and/or used decoration strategy. This was succeeded by fine-tuning this objective, which managed to get outstanding supercapacitive performances. This brief technical note epitomizes various PPy-based metallic hybrid materials with different nano-architectures, emphasizing its technical implications in fabricating high-performance electrode material for supercapacitor applications.

Babel V., Hiran B.L.

Polyaniline (PANI) is one of the most studied intrinsically conducting polymers. Polyaniline inclusion with different porous materials is a very attractive research area. In this review, the preparation, properties, and applications of PANI composites have been summarized. PANI was found to be promising among the other conducting polymers and incorporated with different materials like graphene, graphene oxide, metal oxide, carbon, carbon nanotube, silica, silicon dioxide, biomolecules, and metal organic frameworks to enhance the area of application. Metal organic framework (MOF) itself has a vast area of application so incorporation of PANI with MOF can open up tremendous possibilities. An attempt has been made to draw attention to the recent spotlight research area that is, PANI-MOF composites.

Pang A.L., Arsad A., Ahmadipour M.

Polypyrrole (PPy) has unique features such as easy synthesis, environmental stability, and high electrical conductivity (approximately 105 S/cm and even >380 S/cm) for bulk and thin-film materials. Thus, PPy is applied in numerous well-established applications, such as in sensors, supercapacitors, and resonators. These applications take advantage of the unique properties achieved through the structure and properties of PPy. This article comprehensively elaborates the methods used to synthesize conductive PPy, along with the important factors affecting its conductivity. Emphasis is given to versatile and basic approaches that enable control of the microstructural features that eventually determine PPy conductivity. Despite the intensive research in this area, no previous study has presented all possible relevant information about PPy fabrication and the important factors influencing its electrical conductivity.

Gor’kov K.V., Talagaeva N.V., Kleinikova S.A., Dremova N.N., Vorotyntsev M.A., Zolotukhina E.V.

Palladium-polypyrrole (Pd-PPy) composites synthesized via one-step and one-pot redox procedure have been tested as electrocatalysts for formaldehyde oxidation in aqueous solution under both inert and oxygen atmospheres. It has clearly been shown that inert electrode coated by the Pd-PPy composites demonstrates a high catalytic activity. Electrochemical response of Pd-PPy modified electrodes depends on the anodic potential range, pH and concentration of formaldehyde in solution as well as on the presence of oxygen in reaction atmosphere. It has been found that Pd-PPy composites are prospective materials for amperometric detection of formaldehyde in aqueous solution, even under oxygen atmosphere, as well as in the presence of methanol or/and formate-anions.

Hakimi N., Zouaoui A., Satour F.Z., Sahari A., Zegadi A.

We report on the synthesis and characterization of cobalt microparticles insertion into the composite material poly [4-(pyrrol-1-yl methyl) benzoic acid]. These were deposited on indium tin oxide (ITO) coated glass substrates. Poly [4-(pyrrol-1-yl methyl) benzoic acid] films, 2.3 µm thick, were prepared by electrochemical oxidation of [4-(pyrrol-1-yl methyl) benzoic acid] monomer in an acetonitrile medium. The insertion of cobalt particles was carried out by immersing the modified electrode (ITO/polymer) in a cobalt metal salt solution in order to complex the Co2+ cations with the COO− carboxylic groups present in the polymer film, followed by an electrochemical reduction of the polymer–cobalt complex to precipitate cobalt in the form of metal microparticles in the polymer film. The electrochemical study by cyclic voltammetry indicated the insertion of cobalt into the polymer films by complexation and electroreduction. The characterization of the composite material by electrochemical impedance spectroscopy, scanning electron microscopy, X-ray fluorescence and X-ray diffraction spectroscopies confirmed the presence of approximately 2 µm sized cobalt aggregates dispersed in the polymer film. The study of the magnetic behavior of the composite material showed an improvement with the cobalt charge increase.

Inagaki C.S., Oliveira M.M., Bergamini M.F., Marcolino-Junior L.H., Zarbin A.J.

A simple and versatile route to synthesize nanocomposite thin films containing polythiophene, gold nanoparticles and carbon nanotubes is demonstrated. The strategy is based on a liquid-liquid interfacial reaction, in which polythiophene and gold nanoparticles are concomitantly synthesized through a reaction between an aqueous solution of tetrachloroauric acid and a n-hexane solution of thiophene containing carbon nanotubes previously dispersed. The three-component nanocomposite is obtained directly as a thin and homogeneous film, self-assembled at the liquid-liquid interface, and easily transferable to ordinary substrates. Different reaction times were investigated, and the materials were characterized by several techniques, such as SEM, TEM, profilometry and EDS to inform about the morphology and the elementary composition, FTIR, Raman, TGA, UV–Vis and DRX about the structure of the materials and the electrochemical properties were investigated by cyclic voltammetry. The presence of carbon nanotubes accelerates the reaction, yielding greater amount of product when compared to similar reactions conducted without the carbon nanotubes. The proportion between the components, amount of products and film thickness can be controlled by the reaction time. It is observed that the amount of both polythiophene and gold nanoparticles increases with the increasing reaction time, inducing the formation of polymer agglomerates over de carbon nanotubes and the anisotropic growth of gold nanoparticles. The presence of CNT increases the electrochemical stability of the films when compared to similar ones without CNT. The potentiality of the prepared nanocomposite as electrochemical sensor was evaluated for voltammetric determination of dopamine. Best results were found for a PT/Au/CNT film prepared after 4.5 h of reaction, with a limit of detection of 0.69 μmol L−1.

Kiani G., Nourizad A., Nosrati R.

Two different types of polypyrrole/Ag nanocomposites were prepared by the use of in-situ chemical polymerization of pyrrole monomers in the presence of silver nitrate. Template-free and template-assisted methods were used to the preparation of polypyrrole nanosphere/Ag nanocomposite and polypyrrole fiber/Ag nanocomposite, respectively by the use of ammonium persulfate as oxidant and lithium perchlorate (LiClO4) as dopant agent. The materials were characterized using SEM imaging and EDS analysis. Thin films of prepared nanocomposites were spin coated on interdigitated electrodes to study the ammonia gas sensing property. It was found that ammonia gas sensing performance including sensitivity, response time, and recovery time of polypyrrole fiber/Ag nanocomposite sensor is better than that of polypyrrole nanosphere/Ag nanocomposite sensor. It was also revealed that polypyrrole fiber/Ag nanocomposite sensor was not saturated even in the presence of 250 ppm ammonia gas whereas polypyrrole nanosphere/Ag nanocomposite was saturated with 100 ppm ammonia gas concentration.

Kaloni T.P., Giesbrecht P.K., Schreckenbach G., Freund M.S.

The field of organic electronics has been heavily impacted by the discovery and development of π-conjugated conducting polymers. These polymers show great potential for integration into future optical and electronic devices due to their capacity to transition between semiconducting and conducting states as well as the ability to alter mechanical properties by controlled doping, chemical modification, and stacking or creating composites with other materials. Among π-conjugated polymers, polythiophene and its derivatives has been one of the most extensively studied and is widely investigated computationally and experimentally for use in electronic devices such as light-emitting diodes, water purification devices, hydrogen storage, and biosensors. Various theoretical modeling studies of polythiophene ranging from an oligothiophene approach to infinite chain lengths (periodic boundary conditions) have been undertaken to study a variety of electronic and structural properties of these polymers. In this review,...

Poletti Papi M.A., Caetano F.R., Bergamini M.F., Marcolino-Junior L.H.

The present work describes the synthesis of a new conductive nanocomposite based on polypyrrole (PPy) and silver nanoparticles (PPy-AgNP) based on a facile reverse microemulsion method and its application as a non-enzymatic electrochemical sensor for glucose detection. Focusing on the best sensor performance, all experimental parameters used in the synthesis of nanocomposite were optimized based on its electrochemical response for glucose. Characterization of the optimized material by FT-IR, cyclic voltammetry, and DRX measurements and TEM images showed good monodispersion of semispherical Ag nanoparticles capped by PPy structure, with size average of 12±5nm. Under the best analytical conditions, the proposed sensor exhibited glucose response in linear dynamic range of 25 to 2500μmolL-1, with limit of detection of 3.6μmolL-1. Recovery studies with human saliva samples varying from 99 to 105% revealed the accuracy and feasibility of a non-enzymatic electrochemical sensor for glucose determination by easy construction and low-cost.

Singu B.S., Yoon K.R.

We report the simple one-step synthesis of a reduced graphene oxide–manganese oxide (rGO-MnO2) nanocomposite using graphene oxide (GO) and KMnO4 in the presence of sulfuric acid. The crystal structure, morphology, thermal, pore size, and other physical properties of the rGO-MnO2 nanocomposite were systematically analyzed by X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller analysis. XPS analysis confirmed the synthesis of exfoliated GO and rGO-MnO2 nanocomposite. The rGO-MnO2 nanocomposite exhibited a maximum specific capacitance, energy, and power density of 290 F g−1, 25.7 Wh kg−1, and 8008.7 W kg−1, respectively, in a 1M Na2SO4 electrolyte, and a high retention (87.5%) of capacitance after 5000 cycles. The enhanced electrochemical properties are caused by good contact between MnO2 nanorods and graphene nanosheets, and the higher conductive and capacitive behavior of graphene.

Elsherif O.S., Muftah G.E., Abubaker O., Dharmadasa I.M.

Fluorine doped tin oxide (FTO) thin films with adequate properties to be used as transparent electrical contact for PV solar cells were synthesised using the spray pyrolysis technique, which provides a low cost operation. The deposition temperature and the fluorine doping have been optimized for achieving a minimum resistivity and maximum optical transmittance. No post-deposition annealing treatments were carried out. The X-ray diffraction study showed that all the FTO films were polycrystalline with a tetragonal crystal structure and preferentially oriented along the (200) direction. The grain size ameliorates with the increase in substrate temperature. The samples deposited with the substrate temperature at 440 °C and fluorine content of 20 wt % exhibited the lowest electrical resistivity (1.8 × 10−4 Ω cm), as measured by four-point probe. Room-temperature Hall measurements revealed that the 20 wt% films are degenerate and exhibit n-type electrical conductivity with carrier concentration of ~4.6 × 1020 cm−3, sheet resistance of 6.6 Ω/□ and a mobility of ~25 cm2 V−1 s−1. In addition, the optimized growth conditions resulted in thin films (~500 nm thickness) with average visible transmittance of 89 % and optical band-gap of 3.90 eV. The electrical and optical characteristics of the deposited films revealed their excellent quality as a TCO material.

Bonyani M., Mirzaei A., Leonardi S.G., Neri G.

AgNPs/PMA hybrid nanocomposite materials with different Ag loadings have been synthesized using a simple chemical route assisted by UV irradiation. The hybrid composites were characterized by means of SEM and TEM, UV–vis spectroscopy and XPS. The as synthesized hybrid samples, composed of small Ag nanoparticles (AgNPs) embedded within the PMA (poly-methacrylic-acid) matrix, have been used to modify the working electrode of disposable screen printed carbon electrodes (SPCEs). It has been observed that hybrid composite with the lowest Ag loading forms dendritic silver structures on the surface of working electrode, whereas at higher loadings massive structures were formed. The electrocatalytic properties of the AgNPs/PMA/SPCEs were investigated toward the reduction of nitrate at neutral pH. Based on these modified electrodes, both voltammetric and amperometric sensors were developed for the electrochemical sensing of nitrate. Voltammetric sensor showed a wide linear range (0–20 mM) and high sensitivity (130 μA mM −1  cm −2 ).