Facile Fabrication of Polyaniline/Pbs Nanocomposite for High-Performance Supercapacitor Application

Synthesis and characterization of polyaniline, sucrose octaacetate and chitosan blend for removal of remazol black by adsorption: Equilibrium, kinetics, and regeneration

In this work, a polymeric blend of polyaniline (PAni) and chitosan (Chi), modified with Sucrose Octaacetate (SOA), was synthesized and characterized using different techniques. The blend was used as an adsorbent to remove Remazol Black (RB) dye from aqueous solutions. The blend was synthesized using the chemical oxidation method with ammonium persulfate as the oxidizing agent. Characterization was carried out using SEM, FT-IR, UV-Vis, BET, TGA, Conductivity, and PZc techniques. The blend structure appeared as clusters, providing a favorable surface area for adsorption. The results showed that SOA improved the conductivity of the blend without altering the structure and oxidative state of PAni. The study investigated the adsorption of RB, considering the influence of adsorbent dosage, initial dye concentration, pH, and temperature. Kinetic and equilibrium studies, thermodynamic analysis, synthetic effluent testing, and adsorbent reuse tests were conducted. The optimal adsorption conditions, within the studied range, were adsorbent dosage of 0.25 g L-1, dye concentration of 60 mg L-1, pH range of 2 to 7, and temperature of 30 °C. Equilibrium results indicated that the Langmuir model was the most representative, with a maximum adsorption capacity of qmax = 285.23 mg g-1 and RL = 0.01, indicating favorable adsorption. The kinetic study revealed an equilibrium constant of Keq = 0.421 L mg-1 and a process order 0.63. The adsorption process followed a pseudo-first-order kinetics, demonstrating rapid adsorption on the adsorbent surface. The adsorption was physical, endothermic, and spontaneous, showing increased randomness with temperature. RB removal from synthetic effluent was effective within the pH range of 2-7, with the dye removal efficiency from the aqueous phase remaining above 74 % for up to 4 cycles of adsorption-desorption. The results support the hypothesis that the PAni-SOA@Chi blend is a promising alternative for removing this dye from the waste.

One pot synthesis of poly m-toluidine incorporated silver and silver oxide nanocomposite as a promising electrode for supercapacitor devices

The design and fabrication of novel electrodes with strong electrochemical responses are crucial in advanced supercapacitor technology. In this study, a poly(m-toluidine)/silver-silver oxide (PMT/Ag-Ag2O) nanocomposite was prepared using the photopolymerization method. Various characterization techniques were employed to analyze the prepared nanomaterials. The resulting structure of Ag-Ag2O minimizes ion diffusion distances, increases active sites, and accelerates redox reactions. The electrochemical response of PMT and PMT/Ag-Ag2O electrodes was evaluated in three different electrolyte solutions (Na2SO4, H2SO4, and HCl). The specific capacitance of PMT/Ag-Ag2O nanocomposite was found to be higher than that of PMT alone. Among the tested electrolytes, HCl exhibited the highest specific capacitance of 443 F g-1 at a gravimetric current density of 0.4 A g-1, surpassing H2SO4 (104 F g-1) and Na2SO4 (32 F g-1). Also, the PMT/Ag-Ag2O nanocomposite has demonstrated good cycling stability. It exhibited a high specific power density of 156 W Kg-1 and a specific energy density of 1.8 Wh Kg-1. These results highlight the potential of the prepared PMT/Ag-Ag2O nanocomposite as a nanoelectrode material for high-performance supercapacitors.

High-capacity freestanding supercapacitor electrode based on electrospun Ti3C2Tx MXene/PANI/PVDF composite

In this study, a high-capacity freestanding supercapacitor electrode was developed through electrospinning of a Ti3C2Tx MXene/Polyaniline (PANI)/Polyvinylidene fluoride (PVDF) composite. MXene/PANI composite was achieved through a facile synthesis in which Ti3C2Tx was mixed with PANI Emeraldine salt in N-Methyl-2-Pyrrolidone (NMP) solution using magnetic stirring. PVDF was added to the composite as a flexible binder to facilitate the electrospinning and produce a freestanding electrode. The specific capacitance of the freestanding MXene/PANI/PVDF electrode is 740 Fg-1 at a scan rate of 2 mVs-1, and 895 Fg-1 at a charge-discharge current density of 0.5 Ag-1, which was significantly higher than the specific capacitance of MXene (67 Fg-1) and PANI (54 Fg-1) electrospun electrodes.

Chemical synthesis and super capacitance performance of novel CuO@Cu4O3/rGO/PANI nanocomposite electrode

Copper oxide-based nanocomposites are promising electrode materials for high-performance supercapacitors due to their unique properties that aid electrolyte access and ion diffusion to the electrode surface. Herein, a facile and low-cost synthesis in situ strategy based on co-precipitation and incorporation processes of reduced graphene oxide (rGO), followed by in situ oxidative polymerization of aniline monomer has been reported. CuO@Cu4O3/rGO/PANI nanocomposite revealed the good distribution of CuO@Cu4O3 and rGO within the polymer matrix which allows improved electron transport and ion diffusion process. Galvanostatic charge-discharge (GCD) results displayed a higher specific capacitance value of 508 F g-1 for CuO@Cu4O3/rGO/PANI at 1.0 A g-1 in comparison to the pure CuO@Cu4O3 278 F g-1. CuO@Cu4O3/rGO/PANI displays an energy density of 23.95 W h kg-1 and power density of 374 W kg-1 at the current density of 1 A g-1 which is 1.8 times higher than that of CuO@Cu4O3 (13.125 W h kg-1) at the same current density. The retention of the electrode was 93% of its initial capacitance up to 5000 cycles at a scan rate of 100 mV s-1. The higher capacitance of the CuO@Cu4O3/rGO/PANI electrode was credited to the formation of a fibrous network structure and rapid ion diffusion paths through the nanocomposite matrix that resulted in enhanced surface-dependent electrochemical properties.

Nano-silica from white silica sand functionalized with PANI-SDS (SiO2/PANI-SDS) as an adsorbent for the elimination of methylene blue from aqueous media

Natural resources including sand are one of the best approaches for treating dye-polluted wastewater. The SiO2/PANI-SDS nanocomposite was synthesized by self-assembly and intermolecular interaction. The physicochemical features of the SiO2/PANI-SDS nanocomposite were explored by FT-IR, XRD, SEM, TEM, EDX, and N2 adsorption-desorption techniques to be evaluated as an adsorbent for the MB. The surface area of the SiO2/PANI-SDS is 23.317 m2/g, the pore size is 0.036 cm3/g, and the pore radius is 1.91 nm. Batch kinetic studies at different initial adsorbate, adsorbent and NaCl concentrations, and temperatures showed excellent pseudo-second-order. Several isotherm models were applied to evaluate the MB adsorption on the SiO2/PANI-SDS nanocomposite. According to R2 values the isotherm models were fitted in the following order: Langmuir > Dubinin-Radushkevich (D-R) > Freundlich. The adsorption/desorption process showed good reusability of the SiO2/PANI-SDS nanocomposite.

Ag2S-Ag2O-Ag/poly-2-aminobenzene-1-thiol Nanocomposite as a Promising Two-Electrode Symmetric Supercapacitor: Tested in Acidic and Basic Mediums

A Ag₂S-Ag₂O-Ag/poly-2-aminobenzene-1-thiol (P2ABT) nanocomposite was prepared using the photopolymerization reaction using AgNO₃ as an oxidant. The size of the nanocomposite was about 40 nm, in which the morphology was confirmed using TEM and SEM analyses. The functional groups of Ag₂S-Ag₂O-Ag/P2ABT were confirmed using FTIR; also, XRD confirmed the inorganic Ag₂S, Ag, and Ag₂O formation. This nanocomposite has great performance in supercapacitor applications, with it tested in acidic (1.0 M HCl) and basic mediums (1.0 M NaOH). This pseudo-capacitor has great performance that appeared through the charge time in an acid medium in comparison to the basic medium with values of 118 s and 103 s, correspondingly. The cyclic voltammetry (CV) analysis further confirmed the excellent performance of the supercapacitor material, as indicated by the large area under the cyclic curve. The specific capacitance (C_S) and energy density (E) values (at 0.3 A/g) were 92.5 and 44.4 F/g and 5.0 and 2.52 W·h·Kg^-1 in the acidic and basic mediums, correspondingly. The charge transfer was studied through a Nyquist plot, and the produced R_s values were 4.9 and 6.2 Ω, respectively. Building on these findings, our objective is to make a significant contribution to the progress of supercapacitor technology through a prototype design soon.

Highly Uniform Multi-Layers Reduced Graphene Oxide/Poly-2-aminobenzene-1-thiol Nanocomposite as a Promising Two Electrode Symmetric Supercapacitor under the Effect of Absence and Presence of Porous-Sphere Polypyrrole Nanomaterial

A uniform and highly porous reduced graphene oxide/poly-2-aminobenzene-1-thiol multi-layer (R-GO/P2ABT-ML) nanocomposite was synthesized and characterized. The uniform layer structure and porosity of the nanocomposite, combined with its conductivity, make it an ideal candidate for use as a pseudo supercapacitor. To enhance the capacitance behavior, a porous ball structure polypyrrole (PB-Ppy) was incorporated into the nanocomposite. When tested at 0.2 A/g, the capacitance values of the R-GO/P2ABT-ML and R-GO/P2ABT-ML/PB-Ppy were found to be 19.6 F/g and 92 F/g, respectively, indicating a significant increase in capacitance due to the addition of PB-Ppy. The energy density was also found to increase from 1.18 Wh.kg^-1 for R-GO/P2ABT-ML to 5.43 Wh.kg^-1 for R-GO/P2ABT-ML/PB-Ppy. The stability of the supercapacitor was found to be significantly enhanced by the addition of PB-Ppy. The retention coefficients at 100 and 500 charge cycles for R-GO/P2ABT-ML/PB-Ppy were 95.6% and 85.0%, respectively, compared to 89% and 71% for R-GO/P2ABT-ML without PB-Ppy. Given the low cost, mass production capability, and easy fabrication process of this pseudo capacitor, it holds great potential for commercial applications. Therefore, a prototype of this supercapacitor can be expected to be synthesized soon.

Photodetection Enhancement via Graphene Oxide Deposition on Poly 3-Methyl Aniline

A graphene oxide (GO)/poly 3-methyl aniline (P3MA) photodetector has been developed for light detection in a broad optical region: UV, Vis, and IR. The 3-methyl aniline was initially synthesized via radical polymerization using an acid medium, i.e., K₂S₂O₈ oxidant. Consequently, the GO/P3MA composite was obtained through the adsorption of GO into the surface of P3MA. The chemical structure and optical properties of the prepared materials have been illustrated via XRD, FTIR, SEM, and TEM analysis. The absorbance measurements demonstrate good optical properties in the UV, Vis, and near-IR regions, although a decrease in the bandgap from 2.4 to 1.6 eV after the composite formation was located. The current density (J_ph) varies between 0.29 and 0.68 mA·cm^-2 (at 2.0 V) under dark and light, respectively. The photodetector has been tested using on/off chopped light at a low potential, in which the produced J_ph values decrease from 0.14 to 0.04 µA·cm^-2, respectively. The GO/P3MA photodetector exhibits excellent R (and D) values of 4 and 2.7 mA·W^-1 (0.90 × 10⁹ and 0.60 × 10⁹ Jones) in the UV (340 nm) and IR (730 nm) regions, respectively. The R and D values obtained here make the prepared photodetector a promising candidate for future light detection instruments.

Surface Characterization and Electrical Properties of Low Energy Irradiated PANI/PbS Polymeric Nanocomposite Materials

In this work, nanocomposite samples of polyaniline (PANI) and lead sulfide nanoparticles (PbSNPs) were prepared, utilizing the solution preparation method, for implantation in energy storage elements. The PANI/PbS films were irradiated by different fluences of oxygen beam: 5 × 1016, 10 × 1016, and 15 × 1016 ions.cm−2. The composite was investigated by XRD, SEM, DSC, and FTIR. After ion irradiation, the Tg and Tm values decreased by 4.8 °C and 10.1 °C, respectively. The conductivities, electrical impedances, and electrical moduli of untreated and irradiated samples were examined in frequencies ranging from 102 Hz to 5 MHz. Moreover, the ion beam caused a modification in the dielectric characteristics of PANI/PbS. The dielectric constant ε′ was improved from 31 to 611, and the electrical conductivity increased from 1.45 × 10−3 S/cm to 25.9 × 10−3 S/cm by enhancing the fluence to 15 × 1016 ions.cm−2. Additionally, the potential energy barrier, Wm, decreased from 0.43 eV to 0.23 eV. The induced changes in the dielectric properties and structural characteristics of the PANI/PbS samples were determined. These modifications provide an opportunity to use irradiated PANI/PbS samples for several applications, including microelectronics, batteries, and storage of electrical energy.

Electrochemical Detection of Olivetol Based on Poly(L-Serine) Film Layered Copper Oxide Modified Carbon Paste Electrode (p-L-Serine/CuO/CPE)

Olivetol is an important polyphenol compound and intermediate in the synthesis of cannabinoids possessing many types of biological activities. A facile electrochemical sensor for olivetol was fabricated based on p-L-serine, and copper oxide (CuO) nanoparticles modified carbon paste electrode (p-L-serine/CuO/CPE). The proposed p-L-serine/CuO/CPE was applied to the electrochemical detection of olivetol by cyclic voltammetry (CV) and differential pulse voltammetric (DPV). Through the characterizations of materials and modified electrodes, the p-L-serine/CuO/CPE exhibited enhanced electrochemical signals for olivetol compared to bare CPE and CuO/CPE in both CV and DPV methods. Under the optimized conditions, the proposed p-L-serine/CuO/CPE showed a good quantitative analysis ability and a wide analysis range from 20 to 100 μmol L^-1 of olivetol with a limit of detection of 1.04 μmol L^-1. Based on the reproducibility, repeatability, and stability exhibited by this fabricated sensor and the cheap and accessible raw materials, the p-L-serine/CuO/CPE became a novel determination choice for olivetol in the electrochemical method with the advantages of being cost-effective and convenient.

Flower-Shaped CoS-Co2O3/G-C3N4 Nanocomposite for Two-Symmetric-Electrodes Supercapacitor of High Capacitance Efficiency Examined in Basic and Acidic Mediums

Graphitic carbon nitride (G-C3N4) was synthesized through the direct combustion of urea in the air. The CoS-Co₂O₃/G-C3N4 composite was synthesized via the hydrothermal method of G-C3N4 using cobalt salts. The morphological and chemical structures were determined through XRD, XPS, SEM, and TEM. XRD and XPS analyses confirmed the chemical structure, function groups, and elements percentage of the prepared nanocomposite. SEM measurements illustrated the formation of G-C3N4 sheets, as well as the flower shape of the CoS-Co₂O₃/G-C3N4 composite, evidenced through the formation of nano appendages over G-C3N4 sheets. TEM confirmed the 2D nanosheets of G-C3N4 with an average width and length of 80 nm and 170 nm, respectively. Two symmetric electrodes for the supercapacitor from the CoS-Co₂O₃/G-C3N4 composite. Electrochemical measurements were carried out to determine the charge/discharge, cyclic voltammetry, stability, and impedance of the prepared supercapacitor. The measurements were carried out under acid (0.5 M HCL) and basic (6.0 M NaOH) mediums. The charge and discharge lifetime values in the acid and base medium were 85 and 456 s, respectively. The cyclic voltammetry behavior was rectangular in a base medium for the pseudocapacitance feature. The supercapacitor had 100% stability retention up to 600 cycles; then, the stability decreased to 98.5% after 1000 cycles. The supercapacitor displayed a specific capacitance (C_S) of 361 and 92 F/g, and an energy density equal to 28.7 and 30.2 W h kg^-1 in the basic and acidic mediums, respectively. Our findings demonstrate the capabilities of supercapacitors to become an alternative solution to batteries, owing to their easy and low-cost manufacturing technique.

Alkallas F, M. Ahmed A, Rabia M. Petal-like NiS-NiO/G-C3N4 Nanocomposite for High-Performance Symmetric Supercapacitor

Graphitic carbon nitride (G-C3N4) and NiS-NiO/G-C3N4 nanocomposite have been synthesized via combustion and hydrothermal techniques, respectively. The chemical and morphological properties of these materials were confirmed using different analytical methods. SEM confirms the formation of G-C3N4 sheets containing additional petal-like shapes of NiS-NiO nanoparticles. The electrochemical testing of NiS-NiO/G-C3N4 symmetric supercapacitors is carried out from 0.6 M HCl electrolyte. Such testing includes charge/discharge, cyclic voltammetry, impedance, and supercapacitor stability. The charge/discharge time reaches 790 s at 0.3 A/g, while the cyclic voltammetry curve forms under a high surface area. The produced specific capacitance (C_S) and energy density values are 766 F/g and 23.55 W.h.kg^-1, correspondingly.

Thermodynamic Analysis and Experimental Study on the Oxidation of PbX (X = S, Se) Nanostructured Layers

Heat treatment in an oxygen-containing medium is a necessary procedure in the technology of forming photodetectors and emitters based on lead chalcogenides. Lead chalcogenide layers (PbS, PbSe) were prepared via a chemical bath deposition method. Surface oxidation of lead chalcogenide layers was analyzed using X-ray diffraction and Raman spectroscopy methods, and thermodynamic analysis of the oxidation of PbSe and PbS layers was also performed. The calculated phase diagrams from 20 °C to 500 °C showed good agreement with the experimental results. According to the thermodynamic analysis, the oxidation products depend on the initial composition of the layers and temperature of the annealing. In some cases, the formation of a separate metallic phase Pb is possible along with the formation of lead oxide PbO and other oxides. The performed thermodynamic analysis makes it possible to substantiate the two-stage annealing temperature regimes which ensure an increase in the speed of photodetectors.