Person: TOKGÖZ, SEYİT RIZA
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TOKGÖZ
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SEYİT RIZA
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Publication Electrochemically fabrication of a composite electrode based on tungsten oxide and cobalt on 3d ni foam for high and stable electrochemical energy storage(Elsevier, 2022-08-30) Killi, Halime; Tokgöz, Seyit Rıza; Çarpan, Mürüvvet Arslan; PEKSÖZ, AHMET; TOKGÖZ, SEYİT RIZA; Fen Edebiyat Fakültesi; Fizik Bölümü; GYU-7137-2022; IXW-9711-2023; HRA-2244-2023The present work reports new findings on the electrical energy storage capabilities of WO3/Ni and Co@WO3/Ni electrodes produced via galvanostatic electrochemical deposition. The paper also describes a novel process for cleaning Ni foam, which has significant effect on the electrode's charge accumulation properties. Electro-chemical measurements in an aqueous solution are performed to compare the supercapacitive behavior of the WO3/Ni foam and Co@WO3/Ni foam. The specific capacitance of the former electrode increases from 492.8 to 977.4 F g-1 because of Co adding into tungsten oxide. Furthermore, the former has 42.5% capacitance retention after 7000 charge-discharge cycles, while the latter has 83.7% owing to the Co loading. The specific energies are respectively calculated to be 64.27 Wh kg-1 and 64.44 Wh kg- 1 for the pure WO3/Ni and Co@WO3/Ni elec-trodes. The specific powers are 3761.49 W kg- 1 and 3303.90 W kg- 1 for the former and latter electrodes. Ac-cording to the findings, adding Co to the pure WO3/Ni electrode increases its electrochemical and supercapacitor capabilities, allowing it to be used in energy storage devices.Publication Electrochemically characterized energy storage properties of Ni foam/poly (EGDMA-Co-VPCA)/SWCNT composite electrode produced by surface polimerization method(Elsevier, 2021-05-21) Yıldırım, Hasan; Tokgöz, Seyit Rıza; Peksöz, Ahmet; Kara, Ali; Yıldırım, Hasan; TOKGÖZ, SEYİT RIZA; PEKSÖZ, AHMET; KARA, ALİ; Fen Edebiyat Fakültesi; Fizik Bölümü; 0000-0001-6552-1112; 0000-0003-4050-4222; 0000-0001-9135-1508; 0000-0003-2457-6314; AHB-9353-2022; HRA-2244-2023; IXW-9711-2023; A-8113-2016Poly (EGDMA-co-VPCA)/SWCNT composite film is successfully synthesized on Ni foam substrate by surface polymerization technique. Energy storage properties of Ni foam/poly (EGDMA-co-VPCA)/ SWCNT composite electrode are investigated via cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The as-prepared Ni foam/poly (EGDMA-co-VPCA)/ SWCNT composite electrode exhibits high specific capacitance of 100 F/g at 5 A/g, high power density of 3285.0 W/kg at 8.5 Wh/kg energy density, capacitive retention of 77.7% after 5000 charge-discharge cycles and excellent chemical stability.Publication Fabrication of a new rgo@ppy/ss composite electrode with high energy storage and long cycling life for potential applications in supercapacitors(Elsevier, 2022-10-01) Koşukoğlu, Tülin; Tokgöz, Seyit Riza; TOKGÖZ, SEYİT RIZA; Çarpan, Mürüvvet; Peksöz, Ahmet; PEKSÖZ, AHMET; Fen Edebiyat Fakültesi; Psikoloji Bölümü; HRA-2244-2023; GYU-7137-2022; IXW-9711-2023Electrochemical synthesized PPy/SS and rGO@PPy/SS electrodes are individually characterized from the point of their morphological and structural properties by the SEM, EDX and FTIR techniques. Electrochemical measurements, for instance, CV, EIS, and MS are performed to obtain the supercapacitive behaviour of the electrodes in an aqueous solution of 0.1 M KOH. All the morphological and structural studies confirm the molecular occurrence of PPy and rGO@PPy, and the homogenous distribution of the material onto the SS substrate. The specific capacitances of the electrodes show up as 104.22 F g-1 and 122.53 F g-1 respectively for PPy/SS and rGO@PPy/SS at 10 mV s-1 scan rate. The energy density of rGO@PPy/SS is 212.5 Wh kg- 1 at the current density of 6 A g-1 while the energy density of PPy/SS is 116.66 Wh kg- 1 at the same scan rate. This considerable increase is also shown for the power densities of the electrodes as from 4516.12 W kg- 1 to 6219.51 W kg- 1 at 6 A g-1 by insertion of rGO into PPy/SS. Likewise, with this insertion, an impressive improvement in the cyclic stability of the electrode is seen from 59.5% to 97.6%. In the light of these results, rGO@PPy/SS is considered an extremely promising material for supercapacitor investigations.Publication Energy storage and semiconducting properties of polyaniline/graphene oxide hybrid electrodes synthesized by one-pot electrochemical method(Elsevier, 2021-07-06) Tokgoz, Seyit Rıza; Firat, Yunus Emre; Akkurt, N.; Pat, S.; Peksoz, Ahmet; TOKGÖZ, SEYİT RIZA; Firat, Yunus Emre; PEKSÖZ, AHMET; Fen Edebiyat Fakültesi; Fizik Bölümü; 0000-0003-0510-6640; 0000-0001-9135-1508; IXW-9711-2023; AAK-5283-2021; HRA-2244-2023; AAG-9772-2021Polyaniline/graphene oxide composites are produced by the one-pot electrochemical deposition method and are used as an electrode for supercapacitor energy storage. The electrochemical tests related to the energy storage performance of the PANI/GO electrodes at different mass loading of GO are successfully studied. The biggest specific capacitance for all of the electrodes is observed at a specific current of 0.3 A g(-1). Pure PANI electrode has a specific capacitance of 158.0 F g(-1), a specific energy of 18.2 W h kg(-1), and a corresponding specific power of 118.8 W kg(-1). After the loading of graphene oxide into PANI, the best specific capacitance measured at a current density of 0.3 A g(-1) is 295.9 F g(-1), and the corresponding specific energy and specific power are 34.0 Wh kg(-1) and 126.9 W kg(-1), respectively. The PANI/GO hybrid materials also exhibit a remarkably cycling stability with a capacitance retention range of 62.3%-83.7% after 5000 charge-discharge cycles. Charge transfer resistance of the PANI electrode desreases as GO loading increases. This means that electroactive surface area of the electrode increases due to the addition of GO into PANI. The enhancement in energy storage capability is supported by the increase in electroactive surface area. The high energy storage performance and easy production of PANI/GO materials make them promising electrodes for supercapacitor devices.Publication Fast electrochromic response and high coloration efficiency of al-doped WO3 thin films for smart window applications(Elsevier, 2021-10-18) Arslan, Mürüvvet; Firat, Y. E.; Tokgöz, Seyit Rıza; Peksöz, A.; Arslan, Mürüvvet; TOKGÖZ, SEYİT RIZA; PEKSÖZ, AHMET; Fen Edebiyat Fakültesi; Fizik Bölümü; 0000-0002-3136-315X; 0000-0001-9135-1508; AAG-9772-2021; HRA-2244-2023; GYU-7137-2022; IXW-9711-2023Herein, vertically aligned Al:WO3 nanoplate arrays were directly grown on ITO glass by a facile electrodeposition method and annealed in an argon atmosphere at 450 degrees C for 2h. Besides, this study reports the influence of Al doping on the electrochromic properties of WO3 film in detail. Electrochromic properties such as cyclic voltammetry, chronoamperometry and optical transmittance were analyzed by protonic insertion/extraction in the 1 M LiClO4/propylene carbonate as an electrolyte. The noticeable reversible color changing from transparent to the blue can be realized under the potential bias of +/- 1.0 V. XRD studies show that the produces films have highly crystalline structure. The EDS results clearly confirm the incorporation of Al element into the WO3 network. From the optical absorption measurement, direct band gap energies are calculated as 3.62 and 3.34 eV for the WO3 and the Al:WO3, respectively. Compared to the as-prepared WO3, the Al:WO3 film exhibits outstanding electrochromic performance, including wide optical modulation (55.9%), high coloration efficiency (148.1 cm(2)C(-1)), quick reaction kinetics (1.23 s and 1.01 s for colored and bleaching times, respectively), good rate capability and cycle durability at a wavelength of 632.8 nm. EIS measurements based on a charge-transfer resistance reveal that the dramatic improvement in the electrochemically active surface is achieved in the Al:WO3 film. The increase of active surface facilitates transport kinetics for electron and ion intercalation/deintercalation within the porous metal oxide to enhance coloration efficiency. Comparatively energy levels of the WO3 and the Al:WO3 electrochromic films are also represented. From the Mott-Schottky studies, it is estimated that the donor concentration of the films is of the order of 1020 cm(-3). Taken together, these results not only provide important insight into a promising electrode for electrochromic displays applications, but also offer an economic and effective strategy for manufacturing of other doped metal oxide films.