Investigation of polyaniline films doped with Ni2+ as the electrode material for electrochemical supercapacitors

Ag/Cu doped polyaniline hybrid nanocomposite-based novel gas sensor for enhanced ammonia gas sensing performance at room temperature

Hybrid nanocomposites, which comprise organic and inorganic materials, have gained increasing attention in applications for enhanced sensing response to both reducing and oxidation gases. In this study, a novel nanocomposite is synthesized using chemical polymerization by reinforcing Ag/Cu nanoparticles with different concentrations doped into the polyaniline matrix. This hybrid nanocomposite is used as a sensing platform for ammonia detection with different concentrations (ppm). The homogeneous distribution of Ag/Cu nanoparticles onto the PANI matrix provides a smooth and dense surface area, further accelerating the transmission of electrons. The synergistic effect of the PANI@Ag/Cu matrix is responsible for the outstanding conductivity, compatibility, and catalytic ability of the proposed gas sensor. The structure, morphology, and surface composition of as-synthesized samples were examined using X-ray diffraction, field emission scanning electron microscopy, ultraviolet-visible spectroscopy, energy dispersive spectroscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The results indicated that the resistive sensor based on the PANI@Ag/Cu3 hybrid nanocomposite exhibited the highest response toward ammonia at room temperature, with a response value of 86% to a concentration of 300 ppm. We also investigated the sensing properties of volatile organic compounds, including carbon dioxide, carbon monoxide, ethanol and hydrogen sulphide. Characterization and gas sensing measurements exhibited protonation and deprotonation of the PANI@Ag/Cu heterojunction, which contributes to the ammonia sensing mechanism. Overall, the obtained findings demonstrated that the PANI@Ag/Cu hybrid nanocomposite is a promising material for gas sensing applications in environmental monitoring.

Construction of ultra-stable trinickel disulphide (Ni3S2)/polyaniline (PANI) electrodes based on carbon fibers for high performance flexible asymmetric supercapacitors

Highly flexible supercapacitors (SCs) have attracted significant attention in modern electronics. However, it has been found that flexible, metal sulfide-based electrodes usually suffer from corrosion, instability and low conductivity, which significantly limits their large scale application. Herein, we report on an electrode comprised of highly stable, free-standing carbon fiber/trinickel disulphide covered with polyaniline (CF/Ni₃S₂@PANI). This electrode was prepared and then employed in a high-performance of flexible asymmetric SCs (FASC). The coating layer of polyaniline served as both a protector and conducting shell for the Ni₃S₂ due to the nature of the highly stable N-Ni bonds that formed between the polyaniline and Ni₃S₂. In addition, the lightweight carbon fiber support served as both a current collector and flexible support. The prepared CF/Ni₃S₂@PANI electrode exhibited a significantly enhanced specific capacity (715.3 F·g^-1 at 1 A·g^-1) compared with the carbon fiber/Ni₃S₂ electrode (318 F·g^-1 at 1 A·g^-1). More importantly, the assembled FASC device delivered an impressive energy density of 35.7 Wh·kg^-1 at a power density of 850 W·kg^-1. The FASC device benefited from the interconnected flexible microstructure and the stable bond bridges, so that it could be bent into various angles without noticeably impairing its performance. This effective protective strategy may further inspire the design and manufacture of metallic oxide or sulfide electrode with ultrahigh-stability interbond bridges for high-performance flexible supercapacitors.

Redox-Active Gel Electrolyte Combined with Branched Polyaniline Nanofibers Doped with Ferrous Ions for Ultra-High-Performance Flexible Supercapacitors

In this work, the effects of utilizing an Fe²⁺/Fe³⁺ redox-active electrolyte and Fe²⁺-doped polyaniline (PANI) electrode material on the performance of an assembled supercapacitor (SC) were studied. The concentration of the redox couple additive in the electrolyte of the SC was optimized to be 0.5 M. With the optimized concentration of 0.4 M Fe²⁺, the doped PANI branched nanofibers electropolymerized onto titanium mesh were much thinner, cleaner, and more branched than normal PANI. A specific capacitance (C_s) of 8468 F g⁻¹ for the 0.4 M Fe²⁺/PANI electrode in the 1 M H₂SO₄ + 0.5 M Fe²⁺/Fe³⁺ gel electrolyte and an energy density of 218.1 Wh kg⁻¹ at a power density of 1854.4 W kg⁻¹ for the resultant SC were achieved, which were much higher than those of the conventional PANI electrode tested in a normal H₂SO₄ electrolyte (404 F g⁻¹ and 24.9 Wh kg⁻¹). These results are among the highest reported for PANI-based SCs in the literature so far and demonstrate the potential effectiveness of this strategy to improve the electrochemical performance of flexible SCs by modifying both the electrode and electrolyte.

Ultrasound promoted transition metal doped polyaniline nanofibers: Enhanced electrode material for electrochemical energy storage applications

Here in, we report a simple and facile method to synthesis morphology oriented transition metal (Nickel) doped polyaniline (Ni²⁺/PANI) by chemical oxidative polymerization with the assistance of ultrasonic irradiation. Physicochemical property of the materials examined through XRD and FT-IR. The morphological feature exposed that the sonochemical assisted Ni²⁺ doped PANI is differing from the conventional method and it reveals a notable electrochemical property as in the form of specific capacitance (370 F g^-1 at 0.5 A g^-1) with improved rate capability and sustained cycling performance due to its typical interconnected nano-fibrillar morphology than the other synthesized materials. These intriguing features realized from the properly arranged nanostructure with perfect doping and make as a promising candidate as an electrode material in supercapacitor applications.

Combined use of breath figures process and microphase separation of PS-b-P4VP to produce stable porous nanomaterials

Among various templating strategies available for the preparation of porous polymer films, Breath Figures (BFs) as a fast, low-cost and versatile method has aroused extensive interest.