Electrodeposition Of Polypyrrole Research Articles

A novel cleanroom-free technique for simultaneous electrodeposition of polypyrrole onto array of IDuEs: Towards low-cost, stable and accurate point-of-care TBI diagnosis without trained manpower

Drop-casted polypyrrole (PPY) nanomaterial-based point-of-care Traumatic Brain Injury (TBI) immunosensing platforms reported previously demand trained manpower at field-test, due to poor adhesion between nanomaterial and electrode surface, limiting the point-of-care purpose. The usage of conventional clean-room-based physical and chemical vapor deposition techniques in creating strong adhesion is limited on account of cost and process complexity. Addressing this technical gap, we report a novel low-cost clean-room-free technique that can effectively electrodeposit the PPY simultaneously onto the working areas of array of Interdigitated microelectrodes (IDμEs) from the precursor solution. Through optimization of deposition cycles and molar concentration ratio of monomer and oxidizing agents, a high-quality nanomaterial was electrodeposited on IDμEs' surface. Further, by using the electrodeposited PPY as a bioelectrical transducer, the TBI-specific UCHL1 and GFAP target analytes were simultaneously detected in terms of variation of DC-Resistance and AC-Capacitance parameters, recorded through chemiresistive I-V and chemicapacitive C-F responses of bioelectrodes, respectively. Such simultaneous multianalyte-detection in terms of multiple parameters increases the diversity of decision-making parameters by several folds, inherently aids in enhancing the diagnostic accuracy of TBI test kit. Here, the efficiency of the electrodeposited PPY-based chemiresistive and chemicapacitive immunosensing platforms in detecting TBI-specific target analytes simultaneously in real-time human-plasma samples was analyzed in terms of sensitivity, resolution, LoD, RoD, long-term stability (30 weeks), and the same is compared with drop-cast PPY-based immunosensing platform. Notably, the electrodeposited PPY sensing platforms showed superior performance in terms of sensitivity, LoD, device variability and long-term stability without demanding any trained manpower in the field.

Electrodeposition nanofabrication of carboxylated carbon nanotubes/α-MnO2 nanorods/ polypyrrole composites as high hybrid capacitance electrodes for efficient U(VI) electrosorption

The uranium-containing wastewater resourced from the nuclear fuel cycle presents serious harm to human health and ecological environment. Herein, carboxylated carbon nanotubes/α-MnO2 nanorods/polypyrrole (CMP) composite as high hybrid capacitance (EDL and pseudocapacitance) electrodes with good electrosorption performance for U(VI) were nanofabricated by the electrodeposition of polypyrrole (PPy) on the surface of carboxylated carbon nanotubes/α-MnO2 nanorods composites using potentiostatic method. The morphology and structure characteristics, electrochemical properties and electrosorption U(VI) properties of the CNT/α-MnO2/PPy composites were systematically investigated. The results show that among the CMP composites obtained at different pyrrole concentrations, CMP-0.10 has the highest specific capacitance (366.97F/g), and its electrosorption performance is also the best, which is due to its well balanced porous structure and high hybrid capacitance which favors U(VI) ions transfer and storage. Cyclic voltammetry (CV) curves with obvious redox peaks were observed at low sweep speeds, indicating its hybrid capacitance behavior of CMP composites in which the capacitance contribution can be quantified. The electrosorption experiments were performed in a capacitive deionaiztion (CDI) system in which different factors (voltage, pH, U(VI) concentration and contact time, etc.) on the electrosorption of U(VI) were investigated, which shows that high U(VI) removal could be achieved at a wide pH range. The theoretical simulation using different models shows the best fit of the Langmuir model for the electrosorption isotherms and PFO model for the kinetics. The U(VI) electrosorption capacity reaches 339.45 mg/g at 0.9 V and pH 4.5 for CMP-0.10, which is much higher that achieved at 0.0 V. The facile fabrication, excellent electrochemical and electrosorption performance as well as good cycling stability for the CMP composites highlight their potential application in radioactive wastewater treatment.

Flexible All-Solid-State Asymmetric Supercapacitors Based on PPy-Decorated SrFeO3-δ Perovskites on Carbon Cloth.

The defective structure and high oxygen vacancy concentration of SrFeO3-δ perovskite enable fast ion-electron transport, but its low conductivity still hinders the high electrochemical performance. Herein, to enhance the conductivity of SrFeO3-δ-based electrodes, polypyrrole-modified SrFeO3-δ perovskite on carbon cloth (PPy@SFO@CC) has been successfully fabricated by electrodeposition of polypyrrole (PPy) on the surface of SFO@CC. The optimal PPy700@SFO@CC electrode exhibits a specific capacitance of 421 F g-1 at 1 A g-1. It was found that the outside PPy layer not only accelerates the electron transport and ion diffusion but also creates more oxygen vacancies in SrFeO3-δ, enhancing the charge storage performance significantly. Moreover, the NiCo2O4@CC//PPy700@SFO@CC device maintains a specific capacitance of 63.6% after 3000 cycles, which is ascribed to the weak adhesion forces between the active materials and carbon cloth. Finally, the all-solid-state flexible supercapacitor NiCo2O4@CC//PPy700@SFO@CC is constructed with PVA-KOH as the solid electrolyte, delivering an energy density of 16.9 W h kg-1 at a power density of 984 W kg-1. The flexible supercapacitor retains 69% of its specific capacitance after 1000 bending and folding times, demonstrating a certain degree of foldability. The present study opens new avenues for perovskite oxide-based flexible all-solid-state supercapacitors.

A polyester/spandex blend fabrics-based e-textile for strain sensor, joule heater and energy storage applications

Electronic textiles (e-textiles), as a new class of wearable electronics, have shown diverse applications in modern technologies. However, the development of multi-functional e-textiles with both high strength and elasticity to satisfy different working conditions remains challenge. Herein, the e-textiles based on polyester/spandex blend (PSB) fabrics have been fabricated and their applications in strain sensors, heaters and supercapacitors have been systematically studied. The carbon nanotubes (CNTs) are coated on PSB fabrics via polydopamine (PDA) adhesion. As a strain sensor, the air-permeable PSB-CNT e-textiles show a gauge factor of 18.9 at high strain with a fast response time of 114 ms. The PSB-CNT strain sensor can work better than the cotton-based sensor even at high temperature of 100 °C due to the high heat resistance of polyester, securing its application in severe environment. As a joule heater, the PSB-CNT e-textiles can raise up to 110 °C at 12 V. Further electrodeposition of polypyrrole (PPy) on PSB-CNT can obtain the e-textile electrodes for micro-supercapacitor (MSC). The all-solid-state MSC using PSB-CNT-PPy delivers high specific capacitance of 550 mF cm−2 at 1 mA cm−2. This work offers a simple route for e-textile fabrications and promises potential applications in wearable sensors, heaters, and power sources.

Electrodeposition of polypyrrole as binder-free and high mass-loading electrodes for flexible supercapacitors

Flexible or bendable energy storage devices have drawn great attention recently due to the great demand for the development of soft portable equipment. Conducting polymers (polypyrrole, polyaniline, polythiophene) are particularly interesting powder form candidates for active materials in such devices. A traditional slurry-based technology with low mass loadings (1 mg/cm2) is usually used. However, poor interparticle or particle-substrate connections influence the performance of devices during bending. Furthermore, increasing the mass loading (10 mg/cm2) of commercial-level electrode materials often has the problems of poor electrical and ionic conductivity, which will hinder their practical applications. The electrodeposition process of conducting polymers provides an alternate useful method to synthesize uniform and binder-free electrodes with high mass loadings. Here, electrochemically synthesized polypyrrole is proposed and investigated to increase the energy storage performance with high mass loadings. The electrodeposition polypyrrole electrode with a mass loading of 10 mg/cm2 demonstrates a competitive gravimetric capacitance of 265 F/g at a current density of 1 A/g. In the case of a symmetrical supercapacitor with E-PPy, the differences in the capacitance obtained with different electrode masses are insignificant (59.1 F/g for 2.4 mg/cm2 and 54.9 F/g for 10 mg/cm2). The assembled supercapacitor also possesses outstanding flexibility (as high as 96.3% capacitance retention at 2 A/g) upon bending to 140° for 10 cycles.

Convenient construction of porous dendritic Cu-doped Ni@PPy/stainless steel mesh electrode for oxidation of methanol and urea

In multifunctional catalysts, Ni-based alloys and compounds can be used for methanol oxidation reaction (MOR) and urea oxidation reaction (UOR). Herein, the porous dendritic NiCu@PPy/316L stainless steel mesh (SSM) electrode is prepared by dynamic hydrogen bubble template electrodeposition, followed by cyclic voltammetry electrodeposition of polypyrrole (PPy) conductive polymer on the electrode surface. Among them, dynamic hydrogen bubbles successfully assisted the formation of porous structures in the Ni-based deposition layer. In addition, the morphology of the resulting Ni-based layer further evolves from particle stacking to dendritic with high specific surface area with Cu doping. Eventually, 2-NiCu/SSM achieves current densities of 294.5 mA·cm−2 (MOR) and 278.6 mA·cm−2 (UOR) at 0.8 V, respectively. The PPy coating prevents the agglomeration of NiCu particles in the catalytic layer and further improves the persistence of the electrochemical performance. After 2000 cycles, the current densities of 2-NiCu @PPy/SSM in the new electrolyte are maintained at 89.1% (MOR) and 94.8% (UOR) of the original value, with a 10% increase for MOR and a 7% increase for UOR compared to the sample without PPy coating (2-NiCu /SSM).

Electrodeposition of polypyrrole for high-performance zinc ion battery

Electrodeposition of polypyrrole for high-performance zinc ion battery

Polypyrrole Modified Carbon Nanotube/Polyimide Electrode Materials for Supercapacitors and Lithium-ion Batteries

Lithium-ion batteries have evolved and transcended in recent years to power every device across the spectrum, from watches to electrical vehicles and beyond. However, the lithium-ion battery requires the use of heavy and expensive transition metal oxides that have limited life cycles. Conductive polymer nanocomposites have been shown to possess good electrochemical and thermomechanical properties and are considered to be effective alternatives to transition metal oxides. The fabrication and properties of polyimide matrix-single wall carbon nanotube, SWCNT composite electrode materials, modified by the electrodeposition of polypyrrole, PPy was successfully carried out. The doping of PPy with p-Toluene sulfonic acid, T resulted in a dramatic transformation of the morphology and specific capacitance of the electrode material. Electrochemical impedance spectroscopy, EIS, cyclic voltammetry, CV, and galvanic charge–discharge tests were used to measure the electrode’s specific capacitance and specific capacity. Maximum specific capacitance values of up to 84.88 F/g and 127.13 F/g were obtained by CV and charge–discharge tests, respectively. A capacitance retention of over 80% was obtained after over 500 cycles of testing. The insertion of doped PPy into the electrode material by electrochemical polymerization was shown to positively correlate to the improved electrochemical performance of the nanocomposite. An increase in the porosity of about 34.68% over the non-doped polypyrrole was obtained from EIS measurement and supported by the optical microscope pictures. Increasing the process parameters, such as pyrrole, Py concentration and the amount of dopants, lead to a dramatic increase in the specific capacitance and capacity of the composite electrodes.

The synergetic effect of tannic acid as adhesion promoter in electrodeposition of polypyrrole on copper for corrosion protection

The corrosion protection behavior of polypyrrole (PPy) coating on copper (Cu) surface was studied by electrochemical techniques. Prior to the electrochemical deposition of PPy, the passivation ability of oxalic acid and sodium salicylate was investigated to select the optimized condition. The passivation results showed that both oxalic acid and sodium salicylate can form passive layers before deposition of PPy on Cu. In addition, tannic acid was utilized as an adhesion promoter for improving the binding strength between the Cu surface and the PPy coating. The anti-corrosion performance of the coating was examined by Tafel plot and electrochemical impedance spectroscopy. Compared to oxalic acid system, higher corrosion protection efficiency (90%) is obtained for sodium salicylate doped PPy coating, without the addition of tannic acid. However, after introducing tannic acid into the electrodepositing process, the corrosion protection efficiency for oxalic acid system is increased to 94%. In addition, the adhesion performance had been improved from 0 B to 3 B, with 85% of the coating remained on the substrate after peeling the testing tape.

Multiplying Energy Storage Capacity: In Situ Polypyrrole Electrodeposition for Laser-Induced Graphene Electrodes

Scalability and automation are two cornerstones for advanced manufacturing where laser-induced graphene (LIG) can play a key role. However, it is well known that LIG, employed as an electrode material for electrochemical storage devices, has a severely limited energy storage capability, thus presenting a major roadblock to mass commercial adoption. Herein, a technique based on the in situ electrodeposition of polypyrrole (PPy) onto three-dimensional (3D) porous LIG (LIG@PPy) is proposed for overcoming the inherent charge storage limit of LIG. For demonstration, zinc-ion hybrid microsupercapacitors (ZHMSCs) have been realized by integrating LIG@PPy cathodes with Zn anodes. As a key advantage, the conformal deposition of PPy with high specific capacity significantly enhances the charge storage capacity of the LIG skeleton and improves conductivity while maintaining the structural integrity of the porous structure to ensure fast charge diffusion kinetics. Further benefiting from the use of multivalent ions and asymmetrical electrodes, the prototyped ZHMSC exhibits a wide voltage window (1.7 V) and a remarkable areal capacitance/energy density (149 mF cm–2/54 μWh cm–2), which represents a 200× enhancement from the pristine LIG counterpart. This work provides a simple strategy for unlocking the full energy storage potential of LIG without sacrificing any of its existing advantages, overcoming a major bottleneck that had plagued LIG as a practical cathode material for microsupercapacitors and other energy storage devices.

Simultaneously Embedding Indomethacin and Electrodeposition of Polypyrrole on Various CoCr Alloys from Ionic Liquids.

The aim of the present investigation is the electrochemical deposition of polypyrrole films from choline chloride-based ionic liquids at various potential, period times and simultaneously an indomethacin embedding and release. The electrodeposition films were performed on CoCr commercial type Wirobond C (WBC) and, Heraenium CE (Hera) using as electroprocedures for deposition cyclic voltammetry and chronoamperometry. The morphology of obtained films was investigated using scanning electron microscopy (SEM). An FT-IR investigation of CoCr alloys before and after electrodeposition was able to identify the presence of polymer and drug. The research included an evaluation of the hydrophilic character of all studied samples and their electrochemical characterization in Tanni Zuchi artificial saliva. In the electrochemical study, the following methods have been used: open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization. Indomethacin release from the polymeric film was determined using UV-VIS spectra. Based on Fick’s law of diffusion and indomethacin release profile, a kinetic law for release was established and discussed.

Electrodeposition of polypyrrole coatings doped by benzenesulfonic acid-modified graphene oxide on metallic bipolar plates

Benzenesulfonic acid (BSA)-modified graphene oxide (GO) reinforced polypyrrole (PPY) coatings were electrodeposited on metallic bipolar plates for corrosion protection. The ionization of BSA groups drove the parallel stacking of graphene oxide during the anodic deposition. Meanwhile, the doping effect of BSA groups favored the electro-polymerization of pyrrole and the π-electron delocalization of PPY. The doping level of PPY in the composite coatings increased from 15.6 % to 35.2 % when the concentration of BSA-modified GO (SGO) was increased from 1.5 mg٠mL−1 to 3 mg٠mL−1, while the surface roughness of the coatings decreased from 34.3 nm to 19.3 nm. The corrosion current density under the potentiodynamic polarization test reached 0.18 μA٠cm−2, which was an order of magnitude lower than that of the GO/PPY composite coatings. The interfacial contact resistance of the SGO/PPY coatings was 85 % lower than that of GO/PPY coatings, when the electrical conductivity was increased from 6.72 × 10−3 S٠cm−1 to 13.7 S٠cm−1. The improved performance of composite coatings was attributed to the barrier effect of parallelly stacked graphene sheets, the doping effect of BSA groups grafted on GO, and the two-dimensional template effect of SGO on PPY deposition.

Designing New Material Based on Functionalized Multi-Walled Carbon Nanotubes and Cu(OH)2-Cu2O/Polypyrrole Catalyst for Ethanol Oxidation in Alkaline Medium.

In this work, copper(II) hydroxide (Cu(OH)2) and copper oxide (Cu2O) nanostructures are deposited on functionalized multi-walled carbon nanotubes/polypyrrole to report an efficient electrocatalyst for ethanol oxidation in alkaline medium. In the first step, the deposition of functionalized multi-walled nanotubes of carbon (F-MWCNTs) on the electrode surface was carried out using drop casting mode followed by the electrodeposition of polypyrrole (PPy) and copper nanoparticles (Cu-Nps) using galvanostatic mode. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed in order to study the morphology and the structure of the elaborated catalysts. Electrochemical characterization conducted by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed that the introduction of functionalized multi-walled carbon nanotubes enhances the electric properties of the nanocomposites and offers a large active surface area. The prepared electrocatalyst was then tested in a solution of 0.1 M NaOH containing 0.2 M of ethanol showing high performance (7 mA cm−2 at 0.85 V vs Ag/AgCl) and good stability (over 1800 s) toward ethanol oxidation.

Uniform polypyrrole electrodeposition triggered by phytic acid-guided interface engineering for high energy density flexible supercapacitor

Unevenly distributed polypyrrole (PPy) films/coatings with extensive “dead volumes” via electrodeposition have emerged as a main challenge for high energy density flexible supercapacitor. In this work, we have fabricated a phytic acid-guided graphite carbon felt/polypyrrole (GF@PA@PPy) 3D porous composite with less “dead volumes” via electrodeposition. After the activation of phytic acid (PA), the quantity and content of defects and oxygen-containing groups on the surface of carbon felt (GF) have increased. First, these functional groups improve the hydrophilicity of the surface of GF, resulting in the preferential uniform distribution of pyrrole monomer (Py). While significantly, the synergistic effects between the defects and oxygen-containing groups boost the attraction of pyrrole ring, and thus promotes the formation of perfect PPy films with less “dead volume” on GF. Finally, the supercapacitor assembled from the GF@PA@PPy-40 displays a high areal energy density of 0.0732 mWh cm−2, exceeding the previously reported PPy-based electrodes values. The deeper understanding of the role for the defects and oxygen-containing groups in the synthesis of PPy/carbon materials offers a new strategy to construct advanced PPy-based supercapacitors.

Carbon nitride/polypyrrole composite supercapacitor: Boosting performance and stability

In this work, one-step electrochemical synthesis of a supercapacitor with high performance and stability based on carbon nitride and polypyrrole is described. The new composite was easily obtained through the electrodeposition of polypyrrole on the surface of carbon nitride using an aqueous suspension. This material was fully characterized using both theoretical studies and experimental techniques. The sample showed a capacitance value of 810 F g−1 (at 0.2 A g−1), retaining 92% of its initial value after 6000 charge-discharge cycles at 6.0 A g−1. Furthermore, the composite material has a capacitance value of 610 F g−1 at 9.0 A g−1. To explain these results, it was used impedance spectroscopy and DFT calculations. The computational calculations showed the formation of hydrogen bonds between the NH of the polypyrrole and the π-system of the carbon nitride which stabilized the structures. Besides, a planarization effect could also be observed over the polypyrrole chains. Both results are supported by the experimental data collected from the impedance experiments.

Electrochemical Synthesis of Polypyrrole and Polypyrrole-Indomethacin Coatings on NiCr Alloys Involving Deep Eutectic Solvents

There is an increased interest in the use of the deep eutectic solvents (DESs) as electrolytic media for electrochemical synthesis of conducting polymers, which could influence their characteristics. Moreover, the polypyrrole layers represent an attractive route for pharmaceutical drug release. The paper presents several experimental results regarding the electrodeposition of polypyrrole and of polypyrrole-indomethacin coatings on nickel-chromium NiCr alloy substrates widely used in dentistry, involving DES-based electrolytes, namely eutectic mixtures of choline chloride and malonic acid. This type of electrolyte also allowed an enhanced dissolution of indomethacin as compared to aqueous ones. The electropolymerization process has been investigated by cyclic voltammetry and chronoamperometry. The obtained indomethacin containing polymeric coatings have been thoroughly characterized involving scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, contact angle measurements in simulated body fluid (SBF) and indomethacin release studies. Adherent and uniform polypyrrole-indomethacin layers have been obtained on NiCr alloy substrates. The release tests showed that the polypyrrole coatings containing indomethacin may deliver the drug molecules for longer periods of at least 17 days. The maximum released amount was around 99.6% suggesting these layers may act as an active reservoir for indomethacin. Kinetics analysis based on the Korsmeyer–Peppas model suggested the diffusion of the drug out of the polymer layer as the most probable mechanism governing the release.

Novel porous carbon felt cathode modified by cyclic voltammetric electrodeposited polypyrrole and anthraquinone 2-sulfonate for an efficient electro-Fenton process

A novelty two-step synthesized porous carbon felt (PCF) cathode modified by cyclic voltammetric (CV) electrodeposited polypyrrole (Ppy) and anthraquinone 2-sulfonate (AQS) (PCF/Ppy/AQS) for an efficient electro-Fenton process has been investigated. Brunauer Emmett Teller (BET) and scanning electron microscope (SEM) measurements verified the three-dimensional porous structure of the PCF, revealing that the specific surface area was approximately 2.5 times higher than that of the bare carbon felt (CF), which ensured more active sites available for oxygen reduction reaction (ORR). In addition, the electrodeposited Ppy decreases the charge transfer resistance (Rct) of the PCF cathode. AQS, a type of anthraquinone that can serve as an oxygen reduction catalyzer, could accelerate the ORR process and subsequently improve the performance of the electro-Fenton system. Rotating disk electrode (RDE) analysis confirmed that the ORR catalyzed by AQS was a double-electron reduction process, which contributed to hydrogen peroxide (H2O2) generation. The removal efficiency of total organic carbon (TOC) from Rhodamine B (RhB) could reach 51% within 1 h in the electro-Fenton system equipped with the PCF/Ppy/AQS, resulting in an improvement of approximately 24% compared with the bare CF cathode without porous treatment. The cycle experiment showed a good stability of the PCF/Ppy/AQS cathode. Additionally, the possible mechanism of degradation process in the electro-Fenton equipped with the PCF/Ppy/AQS cathode was proposed based on the electron paramagnetic resonance (EPR) analysis and quenching experiment. The novel fabricated PCF/Ppy/AQS provides an alternative as a high-efficiency cathode, yielding energy savings in the electro-Fenton system.

Ultrathin polypyrrole films on self‐assembled monolayers as an efficient ultramicroelectrode assay

AbstractIn this work, we investigated the effect of electrodeposition of polypyrrole (PPy) films on two different self‐assembled monolayers (SAMs) modified gold electrode for the electrochemical construction of ultramicroelectrode (UME). In order to obtain SAM modified surfaces, 4‐mercapto‐1‐butanol and 11‐mercaptoundecanoic acid were used. The effect of these two chains on pyrrole electropolymerization was compared. Electropolymerization of pyrrole on SAM modified Au electrode was carried out by using cyclic voltammetry (CV) and constant potential electrolysis. To investigate the UME formation, the obtained surfaces were tested in Fe(CN)63−/4− redox system. UMEs were characterized using scanning electron microscopy energy‐dispersive X‐ray spectroscopy, attenuated total reflectance fourier transform infrared spectroscopy and electrochemical impedance spectroscopy. The designed UME was applied as an immobilization matrix to entrap a redox protein, Hemoglobin (Hb), as a model. Direct electron transfer between this protein and the fabricated thiol modified PPy based UME was achieved, which is very challenging on bare electrode surfaces. With this study, a simple, low‐cost and reproducible UME production way has been successfully accomplished and Hb modified UME is promising for different bioanalytical applications, for instance; cellular hydrogen peroxide or nitrite sensing.

Improving Electrochemical Properties of Polypyrrole Coatings by Graphene Oxide and Carbon Nanotubes.

Nanostructured polypyrrole coating was applied on carbon paper via simple dip-coating and electrochemical approach. Hybridization with nanocarbon materials (graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs)) and their effect as an anchoring hybrid layer for the growth of polypyrrole towards improving electrochemical properties are studied. The loading of each component and their w/w ratio were evaluated. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and Raman spectroscopy were employed to characterize the properties of the coatings. The electrochemical properties were investigated by cyclic voltammetry. The results indicated the electrodeposition of polypyrrole is enhanced by the addition of MWCNTs to the GO layer due to the formation of a hierarchical network. The electrochemical performance of the modified electrode was shown to be highly dependent on the employed w/w ratio, reaching a capacitance value of about 40 mF cm−2 for a carbon paper substrate modified with GO:MWCNT in a w/w ratio of 1:2.5 and PPy layer deposited by cyclic voltammetry for 30 cycles. The contribution to total stored charge was found to be primary from the inner capacitance component of about 95.5% contribution.

Effect of carbon nanotubes and finely-dispersed graphite particles on electrodeposition of polypyrrole

The paper investigates the possibility of electrodeposition of composite coatings based on polypyrrole with non-functionalized carbon nanotubes or finely dispersed graphite particles from aqueous solutions of pyrrole with contained suspensions of the corresponding carbon materials stabilized by sodium dodecyl sulfate. The carbon particles/nanotubes suspension added to the electrolyte has been shown to significantly accelerate the electropolymerization of pyrrole and make for the formation of porous composites with an extended surface. Varying the suspension concentration it is possible to prepare composites in various polymer/carbon filler ratios. FTIR and Raman studies show that the chemical structure of the polymer depends on the nature of the doping anion, but not on the carbon particles and nanotubes incorporated in the polymer structure. Doping of the polymer with SDS leads to a relatively low electrochemical activity of the composites, which nevertheless increases significantly under cyclic polarization in sulfuric acid solution (0−700 mV vs. Ag/AgCl) due to saturation of the structure with movable bisulfate ions. The as-formed structure exhibits high stability of its electrochemical parameters.