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    Multi-phase structure electrospun CNF@Ag/Mn/Bi/Fe composite nanofiber enhanced supercapacitor behavior
    (2025-02-15)
    Sinprachim, Tanayt
    ;
    Klompong, Narit
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    Chanlek, Narong
    ;
    Kidkhunthod, Pinit
    ;
    Maensiri, Santi
    This study presents the development of carbon-based multiphase metal oxide nanocomposites (CNF@MO<inf>x</inf>; M = Ag, Mn, Bi, and Fe) incorporating silver, manganese, bismuth, and iron nanoparticles within polyacrylonitrile (PAN)-derived carbon nanofibers. These nanocomposites were fabricated via the electrospinning technique with metal oxide concentrations of 10, 20, and 40 %w. This was followed by annealing in an argon atmosphere. The resulting nanofibers exhibited diameters ranging from 559 to 830 nm, with embedded nanoparticles measuring from 9 to 21 nm. Comprehensive characterization revealed that the nanofibers possessed uniform morphology, high porosity, and robust thermal stability. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) confirmed the valence states of the metal oxides (Ag⁰, Bi³⁺, Mn²⁺, Mn³⁺, Fe²⁺, and Fe³⁺), which are integral to redox reactions and charge storage mechanisms. Among the fabricated composites, CNF@Ag/Mn/Bi/Fe-20 demonstrated the best electrochemical performance, achieving a specific capacitance of 156 F g<sup>−1</sup> at a scan rate of 2 mV s<sup>−1</sup> and outstanding cycling stability with a capacity retention of over 96 % after 1400 charge-discharge cycles. The synergistic combination of double-layer capacitance and pseudocapacitance mechanisms in these nanofibers represents a significant improvement over conventional electrode material. This study highlights CNF@Ag/Mn/Bi/Fe nanocomposites as highly promising candidates for advanced energy storage applications, particularly in supercapacitor technologies.
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    Porous Electrospun Carbon Nanofibers Bearing TiO2 Hollow Nanospheres for Supercapacitor Electrodes
    (2024-03-22)
    Wongprasod, Suchunya
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    Tanapongpisit, Nantawat
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    Laohana, Peerawat
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    Huyen Nguyen, Thi My
    ;
    Van, Hoang Quy
    A facile fabrication method was introduced to enhance the specific surface area and porosity of the carbon nanofibers. The carbon nanofibers bearing TiO<inf>2</inf> hollow nanosphere electrodes were synthesized using an electrospinning technique followed by heat treatment. Varying amounts of as-prepared TiO<inf>2</inf> hollow nanospheres were incorporated into the polymer precursor to examine their impact on the electrode enhancement. The electrochemical performance of supercapacitor electrodes composed of carbon nanofibers bearing TiO<inf>2</inf> hollow nanospheres was investigated. Results revealed that the specific capacitance of the bare carbon nanofibers electrode (170 F g<sup>-1</sup> at a current density of 0.5 A g<sup>-1</sup>) was significantly improved upon when embedded with 5 wt % TiO<inf>2</inf> hollow nanospheres of 191 F g<sup>-1</sup>. Additionally, the carbon nanofibers bearing 5 wt % TiO<inf>2</inf> hollow nanosphere electrodes demonstrated excellent cycling stability, retaining 97% of its initial specific capacitance even after 10000 cycles. Additionally, the electrochemical performance of asymmetric supercapacitors from these electrodes was also demonstrated. These findings highlight the ability of as-prepared TiO<inf>2</inf> hollow nanospheres to improve the efficiency of the carbon nanofibers electrode due to the optimum porosity to the amount of TiO<inf>2</inf> hollow nanospheres in the carbon nanofibers, opening up possibilities for the development of high-performance supercapacitors.
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    Customized electrospun multilayer composite polymer electrolytes: PEO-PAN-NbO2 nanofiber membrane for enhancing the performance of lithium-ion batteries
    (2024-06-01)
    Yonchai, Chutarat
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    Kidkhunthod, Pinit
    ;
    Siriroj, Sumeth
    ;
    Padchasri, Jintara
    ;
    Ground-breaking research into the development of a multilayer composite polymer electrolyte aims to enhance the safety associated with liquid electrolytes utilized in lithium batteries. The electrolyte consists of two outer layers made of electrospun poly(vinylidene fluoride) (PVDF) and a middle layer comprised of a fibrous membrane containing PEO, PAN-PEO, PEO-NbO<inf>2</inf>, and PAN-PEO-NbO<inf>2</inf>. The investigated PEO-PAN-NbO<inf>2</inf> system demonstrates a higher room temperature ionic conductivity of 2.451 × 10<sup>−1</sup> mS cm<sup>−1</sup> than that of single-phase electrolyte systems. Incorporating inorganic fillers such as NbO<inf>2</inf> into PEO polymer electrolytes, in conjunction with PAN copolymerization, significantly enhances ionic conductivity and amplifies surface area. Consequently, the utilization of these techniques that demonstrate increased polymer membranes leads to improved efficiency and security of solid-state electrochemical devices. The multilayer composite polymer electrolyte is created by continuous electrospinning, which allows for precise control and improves safety features.
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    Structural, morphological, optical, and electrochemical properties of Zn-doped CeO2/rGO nanocomposites
    (2025-04-01)
    Utara, Songkot
    ;
    Salidkul, Nuchjaree
    ;
    Karaphun, Attaphol
    ;
    ;
    Chanlek, Narong
    Metal-doped cerium oxide has recently attracted the interest of researchers worldwide because of its various applications in different fields such as supercapacitors, high-sensitivity electrodes or photocatalytic. Metal-doped cerium oxide can be improved utilizing a variety of metals and composites with enhanced conductivity, which advances materials science in semiconductor processing. In this study, undoped and Zn-doped CeO<inf>2</inf> nanoparticles at 5, 10, 15, and 20 at.% were reacted with reduced graphene oxide (rGO) using a hydrothermal method. They were heated at 150 °C for 12 h and then processed in an ultrasonic reactor (20 kHz) at 25 ± 1 °C. Their structural, morphological, elemental, optical, and electrochemical properties were systematically characterized. The calculated average crystallite sizes of CeO<inf>2</inf> peaks ranged from 4.60 ± 0.2 to 12.0 ± 0.4 nm. These samples exhibited a single CeO<inf>2</inf> phase corresponding to a face-centered cubic structure, except for 20 at.% Zn-doped CeO<inf>2</inf>/rGO, which presented a ZnO phase. The samples had lower band gap values than expected for undoped CeO<inf>2</inf> nanoparticles, higher valence states due to their Ce<sup>3+</sup>/Ce<sup>4+</sup> ratios, and a large surface area, 242 m<sup>2</sup>/g, due to Zn-doping in CeO<inf>2</inf> samples. The highest specific capacitance values achieved were 88.49 F/g at 5 mV/s and 134.01 F/g at 0.5 A/g for undoped CeO<inf>2</inf>/rGO. Zn-doping resulted in decreased capacitive behavior with specific capacitance values in the range of 70.78–81.00 F/g at 5 mV/s and 79.24–101.43 F/g at 0.5 A/g. This study for synthesizing Zn/CeO<inf>2</inf>/rGO ternary nanocomposites produced materials with improved band gaps, valence states of Ce<sup>3+</sup>/Ce<sup>4+</sup> ratios, and greater surface area for improved electrocatalytic performance.