Polypyrrole-Based Metal Nanocomposite Electrode Materials for High-Performance Supercapacitors

Cellulose graphitic carbon directed iron oxide interfaced polypyrrole electrode materials for high performance supercapacitors

The rising demand for green and clean energy urges the enlargement of economical and proficient electrode materials for supercapacitors. Herein, we designed a novel electrode material by porous cellulose graphitic carbon (CC) derived from bio-waste cornhusk via the pyrolysis route, and α-Fe2O3 decorated nanostructure with CC (CCIO) was achieved in situ pyrolysis of corn-husk and Fe(NO3)3·9H2O metal salt followed by a coating of polypyrrole (CCIOP). The CC, CCIO, and CCIOP nanocomposite electrodes were characterized by XRD, Raman, FTIR, FE-SEM/EDX, FE-TEM, XPS, and BET analysis. The CCIOP nanocomposite electrode exhibits an enhanced specific capacitance (Csp) of 290.9 F/g, which is substantial to its pristine CC (128.3 F/g), PPy (140.3 F/g), and CCIO (190.7 F/g). The Csp of CCIOP in a three-electrode system, using 1 M Na2SO4 electrolyte exhibits excellent capacity retention of 79.1 % even at a high current density of 10 A/g. The as-fabricated asymmetric supercapacitor (ASC) delivered a remarkable capacity retention of 88.7 % with a coulombic efficiency of 98.8 % even after 3000 cycles. The study shows successful utilization of cellulose from bio-waste cornhusk into a substantial template applicable in future alternative energy storage devices.

Hierarchical Ni-Mn LDHs@CuC2O4 Nanosheet Arrays-Modified Copper Mesh: A Dual-Functional Material for Enhancing Oil/Water Separation and Supercapacitors

The pursuit of superhydrophilic materials with hierarchical structures has garnered significant attention across diverse application domains. In this study, we have successfully crafted Ni-Mn LDHs@CuC2O4 nanosheet arrays on a copper mesh (CM) through a synergistic process involving chemical oxidation and hydrothermal deposition. Initially, CuC2O4 nanosheets were synthesized on the copper mesh, closely followed by the growth of Ni-Mn LDHs nanosheets, culminating in the establishment of a multi-tiered surface architecture with exceptional superhydrophilicity and remarkable underwater superoleophobicity. The resultant Ni-Mn LDHs@CuC2O4 CM membrane showcased an unparalleled amalgamation of traits, including superhydrophilicity, underwater superoleophobicity, and the ability to harness photocatalytic forces for self-cleaning actions, making it an advanced oil-water separation membrane. The membrane's performance was impressive, manifesting in a remarkable water flux range (70 kL·m-2·h-1) and an efficient oil separation capability for both oil/water mixture and surfactant-stabilized emulsions (below 60 ppm). Moreover, the innate superhydrophilic characteristics of the membrane rendered it a prime candidate for deployment as a supercapacitor cathode material. Evidenced by a capacitance of 5080 mF·cm-2 at a current density of 6 mA cm-2 in a 6 M KOH electrolyte, the membrane's potential extended beyond oil-water separation. This work not only introduces a cutting-edge oil-water separation membrane and supercapacitor electrode but also offers a promising blueprint for the deliberate engineering of hierarchical structure arrays to cater to a spectrum of related applications.

Ppy/TiO2-SiO2 nanohybrid series: synthesis, characterization, photocatalytic activity, and antimicrobial potentiality

A series of polypyrrole doped TiO₂-SiO₂ nanohybrids (Ppy/TS NHs) were synthesized thru in-situ oxidation polymerization by varying weight ratio of pyrrole. The structural analysis of NHs were characterized by X-ray Diffraction (XRD) spectra, UV-visible (UV-Vis) spectra and X-ray Photoelectron spectra (XPS) confirmed synthesis of nanomaterials. Surface and morphological study done by adopting, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Transmittance Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis confirmed the homogenous distribution, nano range size formation and mesoporous nature of nanohybrids. Further, electrochemical behavior of synthesized NHs investigated by adopting Electrochemical Impedance Spectroscopy (EIS) showed good kinetic behaviour and electron transport tendency. The nanohybrids and precursors were examined for photocatalytic degradation of methylene blue (MB) dye and revealed enhanced degradation tendency for the NHs series photocatalysts. It was found that variation of pyrrole (0.1 to 0.3 g) to TS nanocomposites (TS Nc) increased the photocatalytic potential of TS Nc. The maximum photodegradation efficacy was found to be 90.48% in 120 min for Ppy/TS0.2 NHs under direct solar light. Additionally, Ppy/TS0.2 NHs performed appreciably towards antibacterial studies against some Gram-positive and Gram-negative deleterious bacteria, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Shigella flexneri microbes.

Polypyrrole-Coated Low-Crystallinity Iron Oxide Grown on Carbon Cloth Enabling Enhanced Electrochemical Supercapacitor Performance

It is highly attractive to design pseudocapacitive metal oxides as anodes for supercapacitors (SCs). However, as they have poor conductivity and lack active sites, they generally exhibit an unsatisfied capacitance under high current density. Herein, polypyrrole-coated low-crystallinity Fe₂O₃ supported on carbon cloth (D-Fe₂O₃@PPy/CC) was prepared by chemical reduction and electrodeposition methods. The low-crystallinity Fe₂O₃ nanorod achieved using a NaBH₄ treatment offered more active sites and enhanced the Faradaic reaction in surface or near-surface regions. The construction of a PPy layer gave more charge storage at the Fe₂O₃/PPy interface, favoring the limitation of the volume effect derived from Na⁺ transfer in the bulk phase. Consequently, D-Fe₂O₃@PPy/CC displayed enhanced capacitance and stability. In 1 M Na₂SO₄, it showed a specific capacitance of 615 mF cm^-2 (640 F g^-1) at 1 mA cm^-2 and still retained 79.3% of its initial capacitance at 10 mA cm^-2 after 5000 cycles. The design of low-crystallinity metal oxides and polymer nanocomposites is expected to be widely applicable for the development of state-of-the-art electrodes, thus opening new avenues for energy storage.

Sol-Gel Synthesis and Characterization of Highly Selective Poly(N-methyl pyrrole) Stannous(II)Tungstate Nano Composite for Mercury (Hg(II)) Detection

The sol-gel process was used to create a new type of polypyrrole-Stannous(II)tungstate nanocomposite by poly(N-methyl pyrrole (PNMPy) sol in Stannous(II)tungstate gel, produced separately using sodium silicotungstic acid and Tn(II)chloride. Tin(II)tungstate (SnWO3) was made by changing the mixing volume ratios of SnWO3 and with a constant amount of an organic polymer. The composite was characterized by TGA, XRD, FTIR, and SEM measurements. A commercially available glassy carbon electrode (GCE) was modified with PNMPy/nano-Stannous(II)WO3 nanocomposites to create a chemical sensor for selective detection of Hg2+ ions using an effective electrochemical methodology. In the I-V technique, selectively toxic Hg2+ ion was targeted selectively, which shows a rapid reaction toward PNMPy/nano-Stannous(II)WO3/Nafion/GCE sensor. It also demonstrates long-term stability, an ultra-low detection limit, exceptional sensitivity, and excellent reproducibility and repeatability. For 0.1 mM to 1.0 nM aqueous Hg2+ ion solution, a linear calibration plot (r2: 0.9993) was achieved, with a suitable sensitivity value of 2.8241 AM−1 cm−2 and an extraordinarily low detection limit (LOD) of 3.40.1 pM (S/N = 3). As a result, the cationic sensor modified by PNMPy/nano-Stannous(II)WO3/GCE could be a promising electrode.

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

Academic research regarding polymeric materials has been of great interest. Likewise, polymer industries are considered as the most familiar petrochemical industries. Despite the valuable and continuous advancements in various polymeric material technologies over the last century, many varieties and advances related to the field of polymer science and engineering still promise a great potential for exciting new applications. Research, development, and industrial support have been the key factors behind the great progress in the field of polymer applications. This work provides insight into the recent energy applications of polymers, including energy storage and production. The study of polymeric materials in the field of enhanced oil recovery and water treatment technologies will be presented and evaluated. In addition, in this review, we wish to emphasize the great importance of various functional polymers as effective adsorbents of organic pollutants from industrial wastewater. Furthermore, recent advances in biomedical applications are reviewed and discussed.