Browsing by Author "Dokan, F. K."

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    Effects of carbon nanomaterials and MXene addition on the performance of nitrogen doped MnO2 based supercapacitors
    (Elsevier Ltd, 2021-12-02) PeçeneK, H.; Yetiman, S.; Dokan, F. K.; Önses, Mustafa Serdar; Yılmaz, E.; Sahmetlioğlu, E.
    Nitrogen-doped composites have the potential to achieve well electrochemical performance by enabling convenient contact of the electrolyte ions for carbon-based materials. A good combination of metal oxide and carbonaceous material is a critical challenge in the development of composites. Herein, we demonstrate a highly capacitive and superior cycle performance of MnO2 based supercapacitor electrodes. The addition of different forms of carbon nanomaterials (carbon nanotube and graphene) and MXene is particularly studied. MnO2 based composite materials are capable of capacitance retention over 95%, with high specific capacitance compared to pure N-doped MnO2. The highest specific capacitance was achieved with MXene based MnO2 composite, which exhibits 457 Fg-1, at a current density of 1 A g−1 with extreme cycling efficiency (102.5%, after 1000 cycles). High conductivity and large surface area are stimulated by the propitious interaction between MnO2 and nanoscale materials, resulting in superior supercapacitor efficiency. This study highlights the possible potential of carbon-based MnO2 composite electrodes which could be useful for future energy storage applications.
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    Scalable fabrication of MXene-PVDF nanocomposite triboelectric fibers via thermal drawing
    (Wiley, 2022-12) Hasan, Md Mehdi; Sadeque, Md Sazid Bin; Albasar, Ilgın; Pecenek, H.; Dokan, F. K.; Onses, M. Serdar; Ordu, Mustafa
    In the data-driven world, textile is a valuable resource for improving the quality of life through continuous monitoring of daily activities and physiological signals of humans. Triboelectric nanogenerators (TENG) are an attractive option for self-powered sensor development by coupling energy harvesting and sensing ability. In this study, to the best of the knowledge, scalable fabrication of Ti3C2Tx MXene-embedded polyvinylidene fluoride (PVDF) nanocomposite fiber using a thermal drawing process is presented for the first time. The output open circuit voltage and short circuit current show 53% and 58% improvement, respectively, compared to pristine PVDF fiber. The synergistic interaction between the surface termination groups of MXene and polar PVDF polymer enhances the performance of the fiber. The flexibility of the fiber enables the weaving of fabric TENG devices for large-area applications. The fabric TENG (3 × 2 cm2) demonstrates a power density of 40.8 mW m−2 at the matching load of 8 MΩ by maintaining a stable performance over 12 000 cycles. Moreover, the fabric TENG has shown the capability of energy harvesting by operating a digital clock and a calculator. A distributed self-powered sensor for human activities and walking pattern monitoring are demonstrated with the fabric. © 2022 Wiley-VCH GmbH.