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Bode Magnitude

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Murat Ates – 1st expert on this subject based on the ideXlab platform

  • Monomer Concentration Effects of Poly (3-methylthiopene) on Electrochemical Impedance Spectroscopy
    , 2020
    Co-Authors: Murat Ates

    Abstract:

    Poly(3-methylthiophene) (PMT) doped with perchlorate anion was prepared electrochemically in the presence of sodium perchlorate (ClO4 ) salt as the supporting electrolyte. The effect of current density, various initial monomer concentrations (0.1, 0.2, 0.5 M) and electrochemical impedance spectroscopy (EIS) on polymer films has been investigated. Cyclic voltammetry of PMT has been examined on carbon fiber microelectrode ( ~7 μm radius) in 0.1 M acetonitrile medium containing NaClO4 in the range of 0.0 to 2.0 V versus Ag in the presence and absence of 3-methylthiophene. Thin films were characterized by Fourier transform infrared attenuated transmission reflectance (FTIR-ATR) spectroscopy and scanning electron microscopy (SEM). SEM revealed a globular, branched and fibrous morphology of poly(3-methylthiophene). After surface modification of carbon fiber microelectrode (CFME), capacitance properties were checked by using electrochemical impedance spectroscopy. Capacitive behaviors of coated CFMEs were defined via Nyquist plot, BodeMagnitude plot, Bode – phase definitions; besides, conductance of modified microelectrodes was studied with Admittance plot. PMT / CFME exhibits high specific capacitance of ~ 4.12 F g -1 in the initial monomer concentration of 0.1 M, in comparison with a value of ~ 3.75 F g -1 for 0.2 M and ~ 2.32 F g -1 for 0.5 M.

  • Electrochemical copolymerization of N-methylpyrrole and 2,2 -bithitiophene; characterization, micro-capacitor study, and equivalent circuit model evaluation
    Bulletin of Materials Science, 2020
    Co-Authors: Murat Ates, Fatih Arican, Tolga Karazehir

    Abstract:

    N-methylpyrrole (N-MPy) and 2,2′-bithiophene (BTh) were electrocopolymerized in 0·2 M acetonitrile–sodium perchlorate solvent–electrolyte couple on a glassy carbon electrode (GCE) by cyclic voltammetry (CV). The resulting homopolymers and copolymers in different initial feed ratios of [N-MPy]0/[BTh]0= 1/1, 1/2, 1/5 and 1/10 were characterized by CV, Fourier-transform infrared reflectance attenuated transmittance (FTIR–ATR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and electrochemical impedance spectroscopy (EIS). The capacitive behaviours of the modified electrodes were defined via Nyquist, BodeMagnitude, Bode-phase and admittance plots. The equivalent circuit model of R(C(R)(QR)(CR)) was performed to fit theoretical and experimental data. The highest low-frequency capacitance (CLF) were obtained as CLF = ∼ 1·23 × 10−4 mF cm−2 for P(N-MPy), CLF = ∼ 2·09 × 10−4 mF cm−2 for P(BTh) and CLF = ∼ 5·54 × 10−4 mF cm−2 for copolymer in the inital feed ratio of [N-MPy]0/[BTh]0= 1/2.

  • Supercapacitor behaviors of polyaniline/CuO, polypyrrole/CuO and PEDOT/CuO nanocomposites
    Polymer Bulletin, 2015
    Co-Authors: Murat Ates, Mehmet Akif Serin, Ilker Ekmen, Yavuz N. Ertas

    Abstract:

    Polyaniline (PANI)/copper oxide (CuO), poly(3,4-ethylenedioxythiophene) (PEDOT)/CuO and polypyrrole (PPy)/CuO have been synthesized electrochemically on glassy carbon electrode in sodium dodecyl sulfate in sulfuric acid solution as an electroactive material. To our best knowledge, the first report on comparison of supercapacitor behaviors of PANI/CuO, PEDOT/CuO and PPy/CuO nanocomposite films was studied by electrochemical impedance spectroscopy, related to the plots of Nyquist, Bode Magnitude and Bode phase. The highest specific capacitance ( C _sp) was obtained as C _sp = 286.35 F × g^−1 at the scan rate of 20 mV × s^−1 for PANI/CuO amongst the PEDOT/CuO ( C _sp = 198.89 F × g^−1 at 5 mV × s^−1) and PPy/CuO ( C _sp = 20.78 F × g^−1 at 5 mV × s^−1) by CV method. Long-term stability of the capacitor has also been tested by CV method, and the results indicated that, after 500 cycles, the specific capacitance of PANI/CuO nanocomposite film is 81.82 % of the initial capacitance. An equivalent circuit model of R _s( C _dl( R _1( Q ( R _2 W )))) has been used to fit the experimental and theoretical data.

Nesimi Uludag – 2nd expert on this subject based on the ideXlab platform

  • Poly(9H-Carbazole-9-Carbothioic Dithioperoxyanhydride) Formation and Capacitor Study
    International Journal of Polymeric Materials, 2015
    Co-Authors: Murat Ates, Nesimi Uludag

    Abstract:

    9H-Carbazole-9-carbothioic dithioperoxyanhydride (2CS2Cz) was chemically synthesized in our previous study. In this work, specific (Csp) and double layer capacitances (Cdl) of the electrocoated poly(9H-carbazole-9-carbothioic dithioperoxyanhydride) P(2CS2Cz) films were obtained on glassy carbon electrode (GCE). The polymers were characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and electrochemical impedance spectroscopy (EIS). Polymer characterizations of FTIR-ATR, and SEM-EDX analysis were taken on carbon fiber microelectrodes (CFMEs). The initial monomer concentration of 2CS2Cz was taken as 0.25, 0.5, and 1.0 mM in 0.1 M sodium perchlorate (NaClO4)/acetonitrile (CH3CN). The capacitance behavior of P(2CS2Cz)/GCE is shown by Nyquist, BodeMagnitude, Bode-phase, and Admittance plots relationship. The low frequency capacitance (CLF = 0.52 mF cm−2) an…

  • Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
    Turkish Journal of Chemistry, 2015
    Co-Authors: Murat Ates, Fatih Arican, Nesimi Uludag, Tolga Karazehir

    Abstract:

    Methyl 4-((9H-(carbazole-9-carbanothioylthio) benzoate (MCzCTB) was chemically synthesized and charac- terized by FTIR, 1 H NMR, and 13 C NMR. A novel synthesized monomer was electropolymerized on a glassy carbon electrode (GCE) in various initial molar concentrations of (MCzCTB)0= 1, 3, 5, and 10 mM in 0.1 M NaClO4/CH3CN and 1 M H2SO4. P(MCzCTB)/GCE was characterized by cyclic voltammetry, Fourier transform infrared-attenuated transmittance reectance, scanning electron microscopy-energy dispersive X-ray, and electrochemical impedance spec- troscopy. The capacitive behavior of the modied electrode was obtained by Nyquist, BodeMagnitude, and Bode-phase plots. The highest capacitance at low frequency was obtained as � 53.1 mF cm 2 from Nyquist plot and 19.454 Fg 1 at a scan rate of 10 mV s 1 for (MCzCTB)0 = 1.0 mM. CS2 and OCH3 groups are electron-withdrawing and electron- donating groups in the monomer structure. These groups aect the polymerization and capacitive behavior of the polymer. The polymer may be used for supercapacitor and biosensor applications in the future.

  • Supercapacitor Behavior of Poly(Carbazole-EDOT) Derivatives/Multi-Walled Carbon Nanotubes, Characterizations and Equivalent Circuit Model Evaluations
    Polymer-plastics Technology and Engineering, 2014
    Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih Arican

    Abstract:

    Three new different comonomers of carbazole-EDOT derivatives had been previously synthesized and characterized in detail. In this study, electroactive materials were electropolymerized onto multi-walled carbon nanotube (MWCNT) modified glassy carbon (GC) electrode in 0.1 M sodium dodecyl sulphate (SDS) solution. The electrochemical impedance spectroscopic results of Nyquist, and BodeMagnitude and Bode-phase plots show that polymers/MWCNT composites possess good capacitive characteristics. P(Com2)/MWCNT/GCE system’s specific capacitance was up to Sc = 132.6 F g−1 at the scan rate of 70 mV s−1 from the area formula, Eq. (1). Furthermore, P(Com2)/MWCNT composite had very rapid charge/discharge ability with specific capacitance of Sc = 75.23 F g−1 at DC potential of 0.3 V from Nyquist plot, and Sc = 90.53 F g−1 at the scan rate of 60 mVs−1 from charge formula, Eq. (2), which is important practical advantage. In addition, such composite had a good cycling performance and a wide potential window. Long-term sta…

Tolga Karazehir – 3rd expert on this subject based on the ideXlab platform

  • Electrochemical copolymerization of N-methylpyrrole and 2,2 -bithitiophene; characterization, micro-capacitor study, and equivalent circuit model evaluation
    Bulletin of Materials Science, 2020
    Co-Authors: Murat Ates, Fatih Arican, Tolga Karazehir

    Abstract:

    N-methylpyrrole (N-MPy) and 2,2′-bithiophene (BTh) were electrocopolymerized in 0·2 M acetonitrile–sodium perchlorate solvent–electrolyte couple on a glassy carbon electrode (GCE) by cyclic voltammetry (CV). The resulting homopolymers and copolymers in different initial feed ratios of [N-MPy]0/[BTh]0= 1/1, 1/2, 1/5 and 1/10 were characterized by CV, Fourier-transform infrared reflectance attenuated transmittance (FTIR–ATR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and electrochemical impedance spectroscopy (EIS). The capacitive behaviours of the modified electrodes were defined via Nyquist, BodeMagnitude, Bode-phase and admittance plots. The equivalent circuit model of R(C(R)(QR)(CR)) was performed to fit theoretical and experimental data. The highest low-frequency capacitance (CLF) were obtained as CLF = ∼ 1·23 × 10−4 mF cm−2 for P(N-MPy), CLF = ∼ 2·09 × 10−4 mF cm−2 for P(BTh) and CLF = ∼ 5·54 × 10−4 mF cm−2 for copolymer in the inital feed ratio of [N-MPy]0/[BTh]0= 1/2.

  • Electrocatalytic Behavior of Hydrogenated Pd-Metallic Glass Nanofilms: Butler-Volmer, Tafel, and Impedance Analyses
    Electrocatalysis, 2020
    Co-Authors: Baran Sarac, Tolga Karazehir, A. Sezai Sarac, Marlene Mühlbacher, Jürgen Eckert

    Abstract:

    Electrocatalytic activity and sorption behavior of hydrogen in nanosized Pd–Si–(Cu) metallic glass thin film and Pd thin film electrodes sputtered on a Si/SiO_2 substrate were investigated by linear sweep voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrode MG4 (Pd_69Si_18Cu_13) exhibits the best performance with the highest electrocatalytic activity in the hydrogen evolution region with less than half of the Tafel slope of Pd thin film of the same thickness and lowest overpotential at 10 mA cm^−2. A new approach has been adopted by a nonlinear fitting of the entire region of the polarization curve (far- and near-equilibrium cathodic and anodic regions) to the Butler-Volmer model. α parameter is lowest for the MG2 electrode (Pd_79Si_16Cu_5), marking that nonequilibrium conditions change the reaction kinetics. Together with MG2, MG4 shows the lowest Bode Magnitude values for hydrogen sorption and evolution regions, indicating that the bonding and release of hydrogen atoms to the electrode is easier. MG4 electrode shows a dramatic decrease of the overpotential after 100 cycles, yielding an increase in hydrogen activity. Besides, MG4 exhibits the sharpest current density drop in the HER region in cyclic voltammetry compared with other MG and Pd electrodes, indicating higher electrocatalytic activity towards hydrogen evolution. The findings highlight the influence of the selected metallic glasses for the design and development of metal catalysts with higher sorption kinetics and/or electrocatalytic turnover. Graphical Abstract .

  • Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
    Turkish Journal of Chemistry, 2015
    Co-Authors: Murat Ates, Fatih Arican, Nesimi Uludag, Tolga Karazehir

    Abstract:

    Methyl 4-((9H-(carbazole-9-carbanothioylthio) benzoate (MCzCTB) was chemically synthesized and charac- terized by FTIR, 1 H NMR, and 13 C NMR. A novel synthesized monomer was electropolymerized on a glassy carbon electrode (GCE) in various initial molar concentrations of (MCzCTB)0= 1, 3, 5, and 10 mM in 0.1 M NaClO4/CH3CN and 1 M H2SO4. P(MCzCTB)/GCE was characterized by cyclic voltammetry, Fourier transform infrared-attenuated transmittance reectance, scanning electron microscopy-energy dispersive X-ray, and electrochemical impedance spec- troscopy. The capacitive behavior of the modied electrode was obtained by Nyquist, BodeMagnitude, and Bode-phase plots. The highest capacitance at low frequency was obtained as � 53.1 mF cm 2 from Nyquist plot and 19.454 Fg 1 at a scan rate of 10 mV s 1 for (MCzCTB)0 = 1.0 mM. CS2 and OCH3 groups are electron-withdrawing and electron- donating groups in the monomer structure. These groups aect the polymerization and capacitive behavior of the polymer. The polymer may be used for supercapacitor and biosensor applications in the future.