Pristine PANI Research Articles

Synergistic effect of gold nanoparticles decorated functionalized carbon nanotubes nanohybrids on the thermal, dielectric, and sensing properties of polyaniline ternary nanocomposites

AbstractThe synthesis of gold nanoparticles reinforced functionalized single‐walled/multi‐walled carbon nanotubes nanohybrid based polyaniline nanocomposites were carried out using in situ polymerization. The chemical interaction and nanostructured morphology of the synthesized nanocomposites are studied using ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, x‐ray diffraction analysis, x‐ray photoelectron spectroscopy, and field emission scanning electron microscopy. Thermal stability of synthesized PANI/Au@f‐SWNTs is boosted by a magnitude of 30°C as compared with the pristine PANI matrix, which is attributed to a strong barrier effect because of the development of tortuous path that resulted from a uniform distribution of Au@f‐CNTs throughout the PANI matrix. For PANI/Au@f‐SWNTs, the AC conductivity and dielectric permittivity are improved by a value of 83.58 S/cm and 1.35 × 10−5 as well as the dielectric loss is reduced by a factor of 0.11 in comparison with the pure PANI matrix at an applied frequency of 106 Hz. PANI/Au@f‐SWNTs and PANI/Au@f‐MWNTs ternary nanocomposites exhibited excellent selectivity toward the hazardous Cr(VI) heavy metal ions in an aqueous medium with a limit of detection of 0.74 and 0.89 μM with a binding constant of 1.028 × 105 and 3.46 × 104 M−1, respectively, that can be selective and sensitive for the detection of Cr(VI) metal ions in water at trace level.

Adsorptive capacity of PANI/Bi2O3 composite through isotherm and kinetics studies on alizarin red

Adsorption offers numerous advantages for eliminating organic pollutants such as dyes, making it a valuable method for water treatment. Polyaniline/Bi2O3 (PANI/Bi2O3) nanocomposite is synthesized from aniline by the chemical oxidative polymerization method. The sample shows a high positive surface charge density as seen from zeta potential analysis. X-ray Diffraction analysis, FTIR analysis, UV–vis spectroscopy technique, thermogravimetric analysis, BET N2 Adsorption-desorption analysis, DLS, and zeta potential analysis are the tools employed to characterize the PANI/Bi2O3 nanocomposite. The impact of PANI/Bi2O3 on the outcome of adsorption is confirmed by comparing the composite with pristine Bi2O3 and PANI. The effect of various factors like time, temperature, initial dye concentration, and varying pH on the adsorption efficiency is studied. A maximum adsorption efficiency of 95 % is observed when 100 mg of PANI/Bi2O3 nanocomposite is utilized for a duration of 100 min. The adsorption efficiency increases at higher temperatures, and a maximum adsorption efficiency is observed at a pH of 11.4. The adsorption isotherms proposed by Freundlich and Langmuir are examined to confirm the adsorption mechanism, which entails the creation of a single layer of dye molecules on the adsorbent's surface. Analysis of kinetic parameters indicates that the reaction follows pseudo-second-order adsorption kinetics. The composite produced demonstrates effectiveness as an adsorbent for removing harmful organic pollutants from water sources.

Room Temperature NH3 Selective Gas Sensors Based on Double-Shell Hierarchical SnO2@polyaniline Composites.

Morphology and structure play a crucial role in influencing the performance of gas sensors. Hollow structures, in particular, not only increase the specific surface area of the material but also enhance the collision frequency of gases within the shell, and have been studied in depth in the field of gas sensing. Taking SnO2 as an illustrative example, a dual-shell structure SnO2 (D-SnO2) was prepared. D-SnO2@Polyaniline (PANI) (DSPx, x represents D-SnO2 molar content) composites were synthesized via the in situ oxidative polymerization method, and simultaneously deposited onto a polyethylene terephthalate (PET) substrate to fabricate an electrode-free, flexible sensor. The impact of the SnO2 content on the sensing performance of the DSPx-based sensor for NH3 detection at room temperature was discussed. The results showed that the response of a 20 mol% D-SnO2@PANI (DSP20) sensor to 100 ppm NH3 at room temperature is 37.92, which is 5.1 times higher than that of a pristine PANI sensor. Moreover, the DSP20 sensor demonstrated a rapid response and recovery rate at the concentration of 10 ppm NH3, with response and recovery times of 182 s and 86 s.

Exploring the potential of polyaniline-calcium titanate (PANI-CaTiO3) nanocomposites in supercapacitors: Synthesis and electrochemical investigation

This work presents the simple approach for the synthesis of CaTiO3 incorporated polyaniline nanocomposites (PANI- CaTiO3) by facile in-situ oxidative polymerization route, to be used as electrode materials for supercapacitors (SCs). The developed samples were evaluated using several analytical methods viz. X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller analysis (BET). The electrochemical performance of the prepared nanocomposites for energy storage application was evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 3 M of KOH as an electrolyte. In comparison to pristine PANI, which demonstrated a specific capacitance of 257 Fg−1, and pure CaTiO3, which exhibited a specific capacitance of 142 Fg−1, the results of cyclic voltammetry (CV) for PANI-35 % CaTiO3 nanocomposites revealed a higher specific capacitance of 966 Fg−1 at 10 mV/s sweep rate. The highest energy density and power density for the PANI-35 % CaTiO3 nanocomposites were shown by galvanostatic charge-discharge (GCD) measurements to be 58.14 Whkg−1 and 3.2 kWkg−1, respectively, at a higher specific capacitance value of 984.21 Fg−1 at 6.86 Ag−1 current density. Additionally, the straight line in low frequency Nyquist plots was linked to the low electrolyte diffusion (Warburg) resistance within the electrode and ions diffusion into the electrode surface, confirming the CV results. Moreover, this study proposes an innovative research concept for the fabrication of electrode materials specifically designed for supercapacitors.

In situ growth of CaMoO4 on electropolymerized PANI as a hybrid electrocatalyst for enhanced oxygen evolution.

Electrochemical water splitting stands as a promising avenue for sustainable hydrogen production, with the oxygen evolution reaction (OER) playing a pivotal role. Efficient and durable electrocatalysts are crucial for expediting the sluggish kinetics of OER. In this work, we investigate the synthesis and performance of a novel CaMoO4/polyaniline (CaMoO4/PANI) composite catalyst for OER. In situ growth of CaMoO4 has been done after the electropolymerization of polyaniline on nickel foam (NF), offering advantages such as improved structural integrity, increased surface area, and enhanced electroconductivity. Electrochemical characterization reveals that CaMoO4/PANI exhibits superior catalytic activity, with an overpotential of 233 mV at 10 mA cm-2, outperforming pristine CaMoO4, PANI, and certain current similar non-noble-metal electrocatalysts. Electrochemical studies reveal that the exceptional activity can be attributed to reduced charge transfer resistance, underscoring the catalyst's enhanced efficiency. Furthermore, multistep chronopotentiometry confirms excellent robustness of the catalyst electrode as well as its excellent mass transportation. This work highlights the potential of inorganic oxide/conductive polymer composites as efficient catalysts for OER, offering insights for future developments in sustainable energy technologies.

Solution processed PANI-rGO-SiO2 nanocomposite with inflated electron injection and transport capabilities as ETL for OLED applications

PANI-rGO-SiO2 nanocomposite as an ETL with varying concentrations of SiO2 was synthesized via oxidative in-situ polymerization process. Their structural and optical properties were investigated by XRD, FESEM, FTIR, Photoluminescence and UV–Vis. Spectroscopy. The PANI depicted a nanofiber-like structure with uniform distribution. The optical band gap of the optimized PGS1 nanocomposite was estimated ∼ 3.01 eV in the visible region of electromagnetic spectrum. TGA results revealed lesser weight loss ∼ 12 % in case of PGS1 nanocomposite than PANI. The light absorption was found at 481 nm in blue region due to charge transfer of SiO2 and PANI-rGO matrix. The current density of PGS1 nanocomposite was observed 76 % greater than pristine PANI using J-V characteristics which showed greater capacities to transfer electron from cathode into emissive layer. These results elucidate that the optimized PGS1 nanocomposite is a compatible candidate for an electron transport layer (ETL) in OLED applications.

Fabrication of binder-free mixed sulphide/PANI nanocomposite based electrode for supercapacitor application

In a pursuit to satisfy the rising energy demand, researchers to create novel, environmentally safe electrode materials for several energy storage devices. The electrochemical performance could be compromised as a result of the polymer binders employed in the electrode coating procedure. Binder-free electrode materials accelerate electron transport pathways by providing enough room to accommodate the active material's large volume changes during charging and discharging. Lower electronegativity of sulphur compared to oxygen provides increased flexibility in the structure of transition metal sulphides which makes them stand out as the promising candidates in the search for innovative electrode materials. Likewise, although PANI possess high conductivity and specific capacitance, it's ineffective to be used in the purest form for practical applications owing to its inability to retain the capacitance when it undergoes multiple charging/discharging cycles. In this work, we describe the development of binder-free Cu-Mn mixed sulphide and its nanocomposite with PANI on carbon fibre paper (CP) substrates. Characterization techniques such as XPS, FE-SEM along with elemental mapping helped in understanding the successful formation of the nanocomposite. In contrast to pure PANI and Cu-Mn mixed sulphide at the same current density in a neutral 1 M Na2SO4 electrolyte, the composite of Cu-Mn mixed sulphide and PANI demonstrated an enhanced areal capacitance of 550.95 mF cm−2 at 1 mA cm−2. Incorporating PANI with Cu-Mn mixed sulphides has not only improved their capacitance but also reduced the rate at which pristine PANI's capacitance degrades when subjected to a greater number of charge/discharge cycles which is reflected in the enhanced capacity retention property of the nanocomposite, wherein the composite maintained 99.02% of its original capacitance at a current density of 10 mA cm−2 than of pure PANI on CP substrates.

Dielectric and Humidity Sensing Properties in Iron Nanoparticle Substituted Polyaniline Composite

The existence of graphene-based Polyaniline nanocomposite has been demonstrated to be exceptional host matrices for entrapping nano-sized particles, and its composites are widely used in a variety of applications such as transducers, sensors, electrodes, microwave absorption, and thermoelectric applications. The purpose of this study is to investigate the dielectric properties and humidity sensing response of a Fe doped PANI/Graphene (PAFG) composite synthesized in-situ polymerization using adhathoda vasica plant extract. The FT-IR, XRD, and SEM-EDX techniques were used to characterize the sample. The dielectric measurements were performed at 298K over a wide frequency range 5x101 to 5x106 Hz. Humidity response studies were performed at room temperature. Iron nanoparticles distributed homogeneously in the PANI matrix were ascertained from IR spectral data. At room temperature, the dielectric properties of the synthesized DS-4 powder outperform those of the synthesized pristine PANI and Fe nanoparticles, with superior dielectric constant and high dielectric loss. When the synthesized iron decorated composite was exposed between 10% and 97% RH, the electrical resistance decreased, which is attributed to the polarization process affecting electrical conductivity within these materials. The PAFG-40% composite exhibited high sensitivity at low humidity levels ranging from 30% to 70% RH.

Polyaniline/Ti3C2Tx functionalized mask sensors for monitoring of CO2 and human respiration rate

Flexible and wearable gas-sensing devices have become increasingly crucial for monitoring air quality and human health. Disposable masks, mainly composed of polypropylene (PP) fibers, can serve as a potential flexible substrate for sensing devices yet have been largely overlooked during the COVID-19 pandemic. In the present work, flexible Ti3C2Tx/PANI-PP composite gas sensors were fabricated by spray-coating delaminated Ti3C2Tx MXene and in-situ polymerization of aniline on a disposable mask substrate. The resulting hybrid gas sensor displayed a wide detection range (25–1500 ppm), reliable reproducibility, long-term stability, and excellent flexibility and selectivity, a remarkable response (15.2%) towards 500 ppm CO2 gas, which is 6.5 times higher than pristine Ti3C2Tx and 2.4 times higher than pristine PANI. The enhanced sensing performance of the composite sensor is mainly attributed to the synergistic effects of the heterojunctions between Ti3C2Tx and PANI, the improved conductivity, and the enlarged specific surface area. We further investigated the influence of various parameters, including humidity, temperature, bending angles, and folding times on the sensing performance of the composite gas sensor. Finally, a wearable wireless Bluetooth sensing device was fabricated for human exhaled breath monitoring at room temperature, demonstrating the potential application of this Ti3C2Tx/PANI-PP composite sensor for respiratory disease diagnosis.

Twistable and tailorable Cu-doped SnO2@PANI textile for wearable ammonia sensing

Herein, a twistable and tailorable NH3 sensor utilizing hollow porous Cu-doped SnO2@PANI (PCS) composite was assembled on a flexible non-woven fabric substrate by in-situ polymerization technique and its gas sensing performance was tested at room temperature (∼25 °C). The results indicated that the well-designed PCS sensor to 50 ppm NH3 exhibited six times higher response (25.4) than the pristine PANI sensor (4.5). The PCS flexible sensor still possessed a response (1.53) for 10 ppb NH3, and the detection limit could reach 5.2 ppb for NH3. Meanwhile, the PCS flexible sensor demonstrated excellent flexibility with response decreases of only 1.97 % after 1000 times bending (120°), and 2.11 % after 100 times folding (150°) and long-term stability through 42 days of monitoring (maintaining 98.4 % response). Furthermore, the PCS sensor displayed insensitivity to relative humidity (20 % − 75 % RH), and the low sensing temperature could reach − 15 °C. The enhanced sensing performance of the PCS sensor was attributed to the synergistic effect of the vital role of abundant oxygen vacancy and − OH groups, as well as the hollow porous interconnected structure and the p-n heterojunction between Cu-doped SnO2 and PANI. This work provides more opportunities to design smart wearable devices for detecting ppb-level NH3 at room temperature.

A non-invasive wearable sweat biosensor with a flexible N-GQDs/PANI nanocomposite layer for glucose monitoring

Understanding the levels change in biomarkers over time, especially glucose, is crucial for diabetics to inform early therapy. Recently, wearable sweat biosensors which operate in a non-invasive way have raised attention, providing continuous monitoring of the severity level. Nevertheless, the key challenges are that multiplexed motions may result in undesirable metal cracking by the rigid electrocatalytic layer, leading to decreased sensitivity and stability. In this work, we designed an N-GQDs anchored PANI matrix to realize flexible wearable biosensors with high detection accuracy. Upon the enhanced electron transfer by N-GQDs, N-GQDs/PANI nanocomposite offers greater sensitivity in H2O2 detection compared to pristine PANI, resulting in a sensitivity of 68.1 ± 1.11 and 44.06 ± 2.1 μA mM−1 cm−2, respectively. Moreover, after the glucose oxidase (GOx) immobilization, GOx/N-GQDs/PANI-based biosensors had shown excellent performance for glucose detection in artificial sweat. Precise glucose detection was also maintained after integrating into a flexible electrode, the sensitivity of the GOx/N-GQDs/PANI-based biosensor had retained 93.2 % with no apparent cracks in the morphology of the nanocomposite layer, compared to GOx/Pt-based one (71.3 %) toward glucose detection after a continuous bending test. Thus, the N-GQDs/PANI nanocomposite layer can provide reliable long-term monitoring with robust electrodes for non-invasive human sweat glucose monitoring on a wearable biosensor.

Dielectric characteristics of multiwall carbon nanotube-filled polyaniline

The dielectric properties of in-situ polymerized polyaniline-multiwalled carbon nanotubes (PANI/MWCNTs) nanocomposite sample were analyzed as a function of temperature (153–353 K) and applied frequency (1 Hz–1000 KHz) over a wide range. To introduce heterogeneity in PANI, MWCNTs (4 wt%) were embedded into the PANI matrix during the polymerization, whereas, to control the electrical conductivity, the synthesized material was reduced via chemical treatment with ammonia. FTIR spectroscopy studies confirm the synthesis of PANI/MWCNTs nanocomposite in lower conducting (emeraldine base) dielectric state. X-ray diffraction (XRD) pattern of the prepared sample reveals the semi-crystalline nature. Thermogravimetric analysis (TGA) investigation indicates that synthesized sample is more stable even at 800 °C. The dielectric studies reveal that the static dielectric constant of the prepared sample enhances with the enhancement in temperature and found to decrease with applied frequency. The enhancement in dielectric constant with temperature may be associated with the enhancement in mobility of the electric dipoles in the conducting polymer. The dielectric constant for the reduced PANI/MWCNTs composite (i.e. ∼1170) is high as compared to reduced pristine PANI (i.e. ∼538). The value of dc electrical conductivity has been decreased from 77 S/cm to 7.81x10−10 S/cm due to reduction of PANI/MWCNTs nanocomposite which indicates the enhancement in dielectric properties. The ac electrical conductivity of synthesized nanocomposite was also found to enhance with an increase in operating temperature, which may be endorsed to the enhancement in activated trapped charge carriers’ concentration.

Polyaniline/Graphene-Functionalized Flexible Waste Mask Sensors for Ammonia and Volatile Sulfur Compound Monitoring.

A flexible resistive-type polyaniline-based gas sensor was fabricated by simple dip-coating of graphene combined with in situ polymerization of aniline on a flexible waste mask substrate. The prepared polypropylene/graphene/polyaniline (PP/G/PANI) hybrid sensor demonstrated a fast response (114 s) and recovery time (23 s), ppb-level detection limit (100 ppb), high response value (250% toward 50 ppm NH3, which is over four times greater than that of the pristine PANI sensor), acceptable flexibility, excellent selectivity, and long-term stability at room temperature. The morphological and structural properties of the composite sensor materials were characterized by scanning electron microscopy and energy-dispersive spectroscopy characterization, and the surface chemistry of the hybrid sensors was analyzed by Fourier transform infrared spectroscopy. The excellent sensing performance was mainly ascribed to the larger specific surface area and efficient conducting paths of the porous PP/G/PANI network. Moreover, the PP/G/PANI hybrid gas sensor exhibited excellent sensing capability on volatile sulfur compounds contained in human breath, indicating that the hybrid sensor can be applied to breath analysis and kidney disease diagnosis.

MnO2 integrated emeraldine polyaniline (PANI- MnO2) nanocomposites with inflated opto-electricaltraitsas ETLs for OLED applications

Herein, we report a preparation method of a new hybrid nanocomposite based on polyaniline nanofibers and manganese dioxidenanorods (PANI-MnO2) via in-situ chemical oxidative polymerization of aniline with the addition of varying MnO2 content by using ammonium peroxydisulphide (APS) as an oxidant. The synthesized PANI-MnO2 nanocomposites were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM), which confirmed their formation. FESEM images revealed that PANI nanofibers coated the MnO2 nanorods. Fourier Transform Infrared Spectroscopy (FTIR) was employed to investigate the interaction between PANI and MnO2 nanoparticles. Optical properties of PANI-MnO2 nanocomposites were examined by UV–Vis. Spectroscopy and the reduced band gap was observed about 1.76 eV for the optimized PMN2 nanocomposite. Blue, violet and green bands were observed in the photoluminescence spectrum for PANI-MnO2 nanocomposites. The color purity of 39% was obtained from CIE software in the light blue region. The conductivity of PMN2 was enhanced by 21% from pristine PANI. Also,the dielectric constant increases with temperature due to better implantation of dipoles of the conjugated polymer PANI in the direction of the electric field These resultsinferred that optimized PMN2 appeared to be a potential candidate as an effective electron transport layer for efficient OLED devices for lighting and display purposes.

Potential Impacts of Prunus domestica Based Natural Gum on Physicochemical Properties of Polyaniline for Corrosion Inhibition of Mild and Stainless Steel.

The lack of an eco-friendly approach towards application of polyaniline as a coating material has been one of the most challenging tasks. Herein, the synthesis of green Prunus domestica gum grafted polyaniline (PDG-g-PANI) composite is reported by a cost-effective emulsion polymerization for application as an efficient anti-corrosion material for mild steel (MS) and stainless steel (SS) in a strong corroding environment. The composite formation was confirmed by Ultraviolet Visible (UV-Visible) and Fourier Transformed Infrared (FTIR) spectroscopies. X-ray diffraction data revealed the amorphous nature of the PDG-g-PANI. Scanning Electron Microscopic (SEM) images showed a bi-layered structure having a parent porous layer of PANI coated with afibrous layer of PDG. The solubility test confirmed the dissolution of PDG-g-PANI in common organic solvents such as acetone, ethanol, propanol, butanol, chloroform, N-Methyl-2-pyrrolidone, dimethyl sulfoxide, and the mixture of propanol and chloroform. The polarization curve, open circuit potential, electrochemical impendence spectroscopy (EIS), and gravimetric analysis were applied to investigate the corrosion protection behavior of the composite on MS and SS in 3.5% NaCl and 1 M H2SO4 solution. The PDG-g-PANI-coated MS exhibited 96% corrosion inhibition efficiency as compared to 86% and 43% for pristine PANI and PDG in 3.5% NaCl solution while PDG-g-PANI-coated SS showed 98% corrosion inhibition efficiency. Moreover, 99% and 96.6% corrosion protection was observed for PDG-g-PANI-coated MS and SS in 1 M H2SO4 solution. Gravimetric studies revealed that PDG-g-PANI coating can protect MS up to 93% for 14 days in salt solution while 97% corrosion inhibition efficiency was retained for 2 months in open air.

Corrosion-protective performance of magnetic CoFe2O4/polyaniline nanocomposite within epoxy coatings

BackgroundOnly a small amount of polyaniline will possibly form passive layers on the surface of the metallic substrate in well-dispersed epoxy coatings. Therefore, introducing the majority of polyaniline additive to the surface of steel can optimize the anti-corrosion performance. MethodsIn this study, novel magnetic CoFe2O4-polyaniline nanocomposite additives are synthesized via oleic acid as a dispersion agent. The morphology of CoFe2O4-oleic acid-polyaniline (CoFe2O4-OA-PANI) is characterized by TEM, SEM-EDS, FTIR spectroscopy, and X-ray diffraction, respectively. Significant findingsThe corrosion protective efficiency of CoFe2O4-OA-PANI on carbon steel is 2.46 times higher than that of pristine PANI after 30 days of immersion in 0.1 M HCl solution experiment. The 3D-optical microscopy (3D-OM) images show that the carbon steel substrate with the CoFe2O4-OA-PANI/epoxy coating has the least corrosion depth among others because a denser protective passive layer is formed well on the contact surface between CoFe2O4-OA-PANI/epoxy coating and carbon steel. Finally, the results of 100-day immersion electrochemical impedance spectroscopy under acidic (9.47 × 1010 Ω) or saline (4.81 × 1010 Ω) conditions reveal that the CoFe2O4-OA-PANI within the epoxy coating has the highest coating resistance, indicating that the CoFe2O4-OA-PANI is a high-efficiency and highly promising anticorrosive agent for commercial applications.

Synthesis, electrical, and dielectric properties of novel polyaniline/strontium di‐nitrate composites

AbstractPolyaniline (PANI) and polyaniline/strontium di‐nitrate [Sr(NO3)2] composites were synthesized by in‐situ chemical oxidative polymerization. The composites with different weight percentages of Sr(NO3)2 were synthesized for the study of the charge transport mechanism. Interaction between Sr(NO3)2 and the PANI was confirmed from the observed peak shift to a lower wavelength in the FTIR spectra. DC conductivity of composites decreased with an increase in the concentrations of Sr(NO3)2. The exponent values, 0.64 < s < 0.75, calculated from Jonscher universal power‐law using AC conductivity forecasts the hopping conduction mechanism. The complex impedance studies showed two semicircles in the Nyquist plot and simulated to an equivalent circuit by constant‐phase element (CPE). The relaxation time for pristine PANI was 2.28 μs, whereas a higher relaxation time of 18.5 μs was observed with 40 wt% Sr(NO3)2, doped composite. The values of dielectric constant, and dielectric loss decreased with increasing frequency and increasing Sr(NO3)2 wt%. Therefore, the results obtained for Sr(NO3)2 doped PANI composites are of scientific and technological interest.

Development of PANI based ternary nanocomposite with enhanced capacity retention for high performance supercapacitor application

The increasing demand for the development of high-performance supercapacitors led researchers to synthesize and develop new electrode materials by optimizing various parameters. In this respect, we have developed ternary nanocomposites using graphene, CuCr2O4 and polyaniline as potent electrode material. We have used simple sonication-assisted mechanical mixing of pre-synthesized N-doped graphene, CuCr2O4 and polyaniline at varied proportions. The prepared composites have been analyzed by different characterization techniques to comprehend the successful formation of the composite. The electrochemical characterizations revealed that the nanocomposite shows the specific capacitance of 443.4 F g−1 at a current density of 1 A g−1 with excellent capacity retention of 92% even after 10,000 GCD cycles, thereby validating the fact that N-doped graphene and CuCr2O4 have enhanced the stability of pristine PANI. [Display omitted]

Cobalt selenide decorated polyaniline composite nanofibers as a newer counter electrode for dye‐sensitized solar cell

AbstractThe cobalt selenide nanoparticles (CoSe NPs) were prepared by a simple hydrothermal method, and polyaniline nanofibers (PANI NFs) were prepared by a chemical oxidative polymerization and its composite NFs were prepared by incorporating CoSe onto PANI at the optimized wt% 1:1 by ultrasonication to use as a newer photocathode for dye‐sensitized solar cells (DSSCs). The physio‐chemical properties of the prepared CoSe NPs/PANI NFs composite NFs were investigated by field emission scanning electron microscope, X‐ray diffractometer, and Raman spectroscopy. The results revealed that the phase pure CoSe NPs were decorated onto the PANI NFs without affecting their physio‐chemical nature. The electrochemical characteristics of CoSe NPs/PANI NFs composite NFs as photocathode were investigated by electrochemical AC‐impedance, cyclic voltammetry, and Tafel polarization studies. The CoSe decorated PANI composite NFs displayed excellent electrocatalytic behavior toward the tri‐iodide reduction. Further, DSSC fabricated with CoSe/PANI composite NFs as the photocathode exhibited the highest photoconversion efficiency of 9.14% than that of the pristine CoSe NPs and PANI NFs‐based counter electrodes (CEs). This is attributed to the synergistic electrocatalytic ability of CoSe NPs and the multiple interfacial charge transferability of PANI NFs. These results suggest that CoSe decorated PANI composite NFs could be used as a promising CE to fabricate high‐performance DSSC.

Composites of polyanine/CdTe for corrosion protection of mild steel XC 70 in a 3.5% NaCl solution

In this work a novel composite of polyaniline and cadmium telluride was electrochemically synthesized on transparent indium thin oxide plates from an aqueous disulfuric acid solution 0.5 M. The aqueous disulfuric acid solution contained LiClO4 as a supporting electrolyte, aniline 0.01 M as a monomer and CdTe as a semi-conductor doping agent. Extensive experimental characterization results have shown the superior anticorrosion properties of such a material. The authors provide a review of all experimental data. As well, they quantify the above mentioned anticorrosion properties when applied to a mild stainless steel (XC 70). The electrochemical properties of the composites were evaluated by cyclic voltamperometry and electrochemical impedance spectroscopy and confirmed the notably enhanced anticorrosive properties of the synthesized composite material: This improved anti-corrosion performance was correlated to the exhibited large resistance and the greater double layer capacitance compared to those seen in pure PAni coatings. Anticorrosion behavior of the composite Polyaniline/CdTe compared with pure polyaniline coating on mild steel is investigated in a 3.5% NaCl solution of pH 1.73, using the electrochemical impedance spectroscopy (EIS) and polarization curves (Tafel) methods. It was found that the pristine PAni film improved the corrosion protection efficiency of mild steel when it was used as only a film without any additives. However, the composite PAni/CdTe coating was shown to significantly improve the protection of mild steel against corrosion due to the efficient anticorrosive properties of this composite. This result indicates that the use of the novel PAni/CdTe composite is rather a promising approach for protecting mild steel substrate from corrosion and that it may be used in other fields of interest.