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Murat Ates - One of the best experts on this subject based on the ideXlab platform.
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Monomer Concentration Effects of Poly (3-methylthiopene) on Electrochemical Impedance Spectroscopy
2020Co-Authors: Murat AtesAbstract: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, Bode – Magnitude 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.
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Electrochemical copolymerization of N-methylpyrrole and 2,2 -bithitiophene; characterization, micro-capacitor study, and equivalent circuit model evaluation
Bulletin of Materials Science, 2020Co-Authors: Murat Ates, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Supercapacitor behaviors of polyaniline/CuO, polypyrrole/CuO and PEDOT/CuO nanocomposites
Polymer Bulletin, 2015Co-Authors: Murat Ates, Mehmet Akif Serin, Ilker Ekmen, Yavuz N. ErtasAbstract: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.
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Poly(9H-Carbazole-9-Carbothioic Dithioperoxyanhydride) Formation and Capacitor Study
International Journal of Polymeric Materials, 2015Co-Authors: Murat Ates, Nesimi UludagAbstract: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, Bode-Magnitude, Bode-phase, and Admittance plots relationship. The low frequency capacitance (CLF = 0.52 mF cm−2) an...
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Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
Turkish Journal of Chemistry, 2015Co-Authors: Murat Ates, Nesimi Uludag, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
Nesimi Uludag - One of the best experts on this subject based on the ideXlab platform.
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Poly(9H-Carbazole-9-Carbothioic Dithioperoxyanhydride) Formation and Capacitor Study
International Journal of Polymeric Materials, 2015Co-Authors: Murat Ates, Nesimi UludagAbstract: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, Bode-Magnitude, Bode-phase, and Admittance plots relationship. The low frequency capacitance (CLF = 0.52 mF cm−2) an...
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Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
Turkish Journal of Chemistry, 2015Co-Authors: Murat Ates, Nesimi Uludag, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Supercapacitor Behavior of Poly(Carbazole-EDOT) Derivatives/Multi-Walled Carbon Nanotubes, Characterizations and Equivalent Circuit Model Evaluations
Polymer-plastics Technology and Engineering, 2014Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract: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 Bode-Magnitude 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...
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A novel synthesis of (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9H-carbazole), alternating polymer formation, characterization, and capacitance measurements
Journal of Solid State Electrochemistry, 2013Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract:In this work, (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9 H -carbazole) (EDOTVBCz) comonomer was chemically synthesized and characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance, and carbon nuclear magnetic resonance spectroscopy. EDOTVBCz was electrocoated on glassy carbon electrode (GCE) in various initial molar concentrations ([EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0) in 0.1 M lithium perchlorate (LiClO_4)/acetonitrile (CH_3CN). P(EDOTVBCz)/GCE was characterized by cyclic voltammetry, FTIR reflectance-attenuated total reflection spectroscopy, scanning electron microscopy–energy dispersive X-ray analysis, atomic force microscopy, and electrochemical impedance spectroscopy (EIS). EIS was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode Magnitude, Bode phase, and admittance plots. The highest low-frequency capacitance value was obtained as C _LF = ∼2.35 mF cm^−2 for [EDOTVBCz]_0 = 3.0 mM. Double-layer capacitance of the polymer/electrolyte system was calculated as C _dl = ∼2.78 mF cm^−2 for [EDOTVBCz]_0 = 1.0 and 3.0 mM. The maximum phase angle was obtained as θ = ∼76.7^o for [EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0 mM at the frequency of 20.6 Hz. AC impedance spectra of P(EDOTVBCz)/LiClO_4/CH_3CN was obtained by performing electrical equivalent circuit model of R ( Q ( R ( CR ))) with linear Kramers–Kronig test. Figure SEM-EDX analysis of P(EDOTVBCz)/CFME EDX point analysis inset: SEM point analysis, [EDOTVBCz]_0 = 3 mM. Chronoamperometric method of constant potential at 1.6 V, 300 s in 0.1 M LiClO_4/CH_3CN
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A novel synthesis of (3,6-bis(2,3-dihydrothieno(3,4-b)(1,4) dioxin-5-yl)-9-(4-vinylbenzyl)-9H-carbazole), alternating polymer formation, characterization, and capacitance measurements
Journal of Solid State Electrochemistry, 2013Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract:In this work, (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9H-carbazole) (EDOTVBCz) comonomer was chemically synthesized and characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance, and carbon nuclear magnetic resonance spectroscopy. EDOTVBCz was electrocoated on glassy carbon electrode (GCE) in various initial molar concentrations ([EDOTVBCz]0 = 1.0, 1.5, 2.0, and 3.0) in 0.1 M lithium perchlorate (LiClO4)/acetonitrile (CH3CN). P(EDOTVBCz)/GCE was characterized by cyclic voltammetry, FTIR reflectance-attenuated total reflection spectroscopy, scanning electron microscopy–energy dispersive X-ray analysis, atomic force microscopy, and electrochemical impedance spectroscopy (EIS). EIS was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode Magnitude, Bode phase, and admittance plots. The highest low-frequency capacitance value was obtained as CLF = ∼2.35 mF cm−2 for [EDOTVBCz]0 = 3.0 mM. Double-layer capacitance of the polymer/electrolyte system was calculated as Cdl = ∼2.78 mF cm−2 for [EDOTVBCz]0 = 1.0 and 3.0 mM. The maximum phase angle was obtained as θ = ∼76.7o for [EDOTVBCz]0 = 1.0, 1.5, 2.0, and 3.0 mM at the frequency of 20.6 Hz. AC impedance spectra of P(EDOTVBCz)/LiClO4/CH3CN was obtained by performing electrical equivalent circuit model of R(Q(R(CR))) with linear Kramers–Kronig test.
Tolga Karazehir - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical copolymerization of N-methylpyrrole and 2,2 -bithitiophene; characterization, micro-capacitor study, and equivalent circuit model evaluation
Bulletin of Materials Science, 2020Co-Authors: Murat Ates, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Electrocatalytic Behavior of Hydrogenated Pd-Metallic Glass Nanofilms: Butler-Volmer, Tafel, and Impedance Analyses
Electrocatalysis, 2020Co-Authors: Baran Sarac, Tolga Karazehir, A. Sezai Sarac, Marlene Mühlbacher, Jürgen EckertAbstract: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 .
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Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
Turkish Journal of Chemistry, 2015Co-Authors: Murat Ates, Nesimi Uludag, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Supercapacitor Behavior of Poly(Carbazole-EDOT) Derivatives/Multi-Walled Carbon Nanotubes, Characterizations and Equivalent Circuit Model Evaluations
Polymer-plastics Technology and Engineering, 2014Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract: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 Bode-Magnitude 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...
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A novel synthesis of (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9H-carbazole), alternating polymer formation, characterization, and capacitance measurements
Journal of Solid State Electrochemistry, 2013Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract:In this work, (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9 H -carbazole) (EDOTVBCz) comonomer was chemically synthesized and characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance, and carbon nuclear magnetic resonance spectroscopy. EDOTVBCz was electrocoated on glassy carbon electrode (GCE) in various initial molar concentrations ([EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0) in 0.1 M lithium perchlorate (LiClO_4)/acetonitrile (CH_3CN). P(EDOTVBCz)/GCE was characterized by cyclic voltammetry, FTIR reflectance-attenuated total reflection spectroscopy, scanning electron microscopy–energy dispersive X-ray analysis, atomic force microscopy, and electrochemical impedance spectroscopy (EIS). EIS was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode Magnitude, Bode phase, and admittance plots. The highest low-frequency capacitance value was obtained as C _LF = ∼2.35 mF cm^−2 for [EDOTVBCz]_0 = 3.0 mM. Double-layer capacitance of the polymer/electrolyte system was calculated as C _dl = ∼2.78 mF cm^−2 for [EDOTVBCz]_0 = 1.0 and 3.0 mM. The maximum phase angle was obtained as θ = ∼76.7^o for [EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0 mM at the frequency of 20.6 Hz. AC impedance spectra of P(EDOTVBCz)/LiClO_4/CH_3CN was obtained by performing electrical equivalent circuit model of R ( Q ( R ( CR ))) with linear Kramers–Kronig test. Figure SEM-EDX analysis of P(EDOTVBCz)/CFME EDX point analysis inset: SEM point analysis, [EDOTVBCz]_0 = 3 mM. Chronoamperometric method of constant potential at 1.6 V, 300 s in 0.1 M LiClO_4/CH_3CN
Fatih Arican - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical copolymerization of N-methylpyrrole and 2,2 -bithitiophene; characterization, micro-capacitor study, and equivalent circuit model evaluation
Bulletin of Materials Science, 2020Co-Authors: Murat Ates, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Synthesis of methyl 4-(9H-carbazole-9-carbanothioylthio) benzoate: electropolymerization and impedimetric study
Turkish Journal of Chemistry, 2015Co-Authors: Murat Ates, Nesimi Uludag, Fatih Arican, Tolga KarazehirAbstract: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, Bode-Magnitude, 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.
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Electrocoated Films of Poly(N-Methylpyrrole-co-2,2′-Bithitiophene-co-3-(Octylthiophene)), Characterizations, and Capacitor Study
International Journal of Polymeric Materials, 2014Co-Authors: Murat Ates, Fatih AricanAbstract:N-Methylpyrrole (N-MPy), 2,2′-bithiophene (BTh), and 3-(Octylthiophene) (OTh) were electrocopolymerized in 0.2 M NaClO4/CH3CN on glassy carbon electrode (GCE). The resulting terpolymers of N-MPy, BTh and OTh in different initial monomer feed ratios such as [N-MPy]0/[BTh]0/[OTh]0 = 1/1/1 and 1/2/5 were characterized by cyclic voltammetry (CV), Fourier-transform infrared attenuated total reflectance spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and electrochemical impedance spectroscopy (EIS). The capacitive behaviors of the modified electrodes were defined via Nyquist, Bode-Magnitude, Bode-phase, and Admittance plots. The equivalent circuit model of Rs(C dl1 (R 1 (QR 2 )))(C dl2 R 3 ) was performed to fit the theoretical and experimental data. The low-frequency capacitance (CLF) were obtained from initial monomer concentrations of 50 mM as CLF = ∼2.34 × 10−4 mFcm−2 for P(N-MPy), CLF = 5.06 × 10−4 mF cm−2 for P(BTh), CLF = 5.07 m F cm−2 for P(OTh), and ...
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Supercapacitor Behavior of Poly(Carbazole-EDOT) Derivatives/Multi-Walled Carbon Nanotubes, Characterizations and Equivalent Circuit Model Evaluations
Polymer-plastics Technology and Engineering, 2014Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract: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 Bode-Magnitude 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...
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A novel synthesis of (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9H-carbazole), alternating polymer formation, characterization, and capacitance measurements
Journal of Solid State Electrochemistry, 2013Co-Authors: Murat Ates, Nesimi Uludag, Tolga Karazehir, Fatih AricanAbstract:In this work, (3,6-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(4-vinylbenzyl)-9 H -carbazole) (EDOTVBCz) comonomer was chemically synthesized and characterized by Fourier transform infrared (FTIR), proton nuclear magnetic resonance, and carbon nuclear magnetic resonance spectroscopy. EDOTVBCz was electrocoated on glassy carbon electrode (GCE) in various initial molar concentrations ([EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0) in 0.1 M lithium perchlorate (LiClO_4)/acetonitrile (CH_3CN). P(EDOTVBCz)/GCE was characterized by cyclic voltammetry, FTIR reflectance-attenuated total reflection spectroscopy, scanning electron microscopy–energy dispersive X-ray analysis, atomic force microscopy, and electrochemical impedance spectroscopy (EIS). EIS was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode Magnitude, Bode phase, and admittance plots. The highest low-frequency capacitance value was obtained as C _LF = ∼2.35 mF cm^−2 for [EDOTVBCz]_0 = 3.0 mM. Double-layer capacitance of the polymer/electrolyte system was calculated as C _dl = ∼2.78 mF cm^−2 for [EDOTVBCz]_0 = 1.0 and 3.0 mM. The maximum phase angle was obtained as θ = ∼76.7^o for [EDOTVBCz]_0 = 1.0, 1.5, 2.0, and 3.0 mM at the frequency of 20.6 Hz. AC impedance spectra of P(EDOTVBCz)/LiClO_4/CH_3CN was obtained by performing electrical equivalent circuit model of R ( Q ( R ( CR ))) with linear Kramers–Kronig test. Figure SEM-EDX analysis of P(EDOTVBCz)/CFME EDX point analysis inset: SEM point analysis, [EDOTVBCz]_0 = 3 mM. Chronoamperometric method of constant potential at 1.6 V, 300 s in 0.1 M LiClO_4/CH_3CN
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Electrocatalytic Behavior of Hydrogenated Pd-Metallic Glass Nanofilms: Butler-Volmer, Tafel, and Impedance Analyses
Electrocatalysis, 2020Co-Authors: Baran Sarac, Tolga Karazehir, A. Sezai Sarac, Marlene Mühlbacher, Jürgen EckertAbstract: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 .
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Electrochemical impedance of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber
Materials Chemistry and Physics, 2011Co-Authors: Murat Ates, Nesimi Uludag, A. Sezai SaracAbstract:Abstract In this paper, copolymer of 9-tosyl-9 H -carbazole (TCz) and pyrrole (Py) comonomers were electrochemically deposited onto carbon fiber micro electrode (CFME) as an active electrode material. An electrochemical impedance study on the prepared electrodes is reported. Poly(TCz-co-Py)/CFME is characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy–energy dispersive X-ray analysis (SEM–EDX), and electrochemical impedance spectroscopy (EIS). Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode-Magnitude and Bode-phase plots. An examination is made of which equivalent circuits of R ( C ( R ( Q ( RW )))) and R ( C ( R ( Q ( RW ))))( CR ) used for modeling the system. The effect of monomer ratio (mole fraction, X TCz = n TCz / n TCz + n Py ) on the formation of copolymer is reported in 0.1 M sodium perchlorate (NaClO 4 )/acetonitrile (ACN) solution. The inclusion of TCz in the copolymer structure was also confirmed by FTIR-ATR, SEM, and CV measurements. The highest low frequency capacitance ( C LF = 22.7 for R ( C ( R ( Q ( RW )))) and C LF = 22.6 mF cm −2 for R ( C ( R ( Q ( RW ))))( CR )) were obtained for X TCz = 0.91.
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Synthesis of 2-(9H-Carbazole-9-yl)ethyl Methacrylate: Electrochemical Impedance Spectroscopic Study of Poly(2-(9H-carbazole-9-yl)ethyl methacrylate) on Carbon Fiber
Journal of Applied Polymer Science, 2011Co-Authors: Murat Ates, Nesimi Uludag, A. Sezai SaracAbstract:In this contribution, 2-(9H-carbazol-9-yl) ethyl methacrylate (CzEMA) monomer was chemically synthesized. The monomer characterization was performed by FT-IR, 1H-NMR, 13C-NMR, and melting point analysis. The electropolymerization of CzEMA was studied onto carbon fiber microelectrodes (CFMEs) as an active electrode material in 0.1M sodium perchlorate (NaClO4)/acetonitrile (ACN) solution. The electropolymerization experiments were done from 1 mM to 10 mM. The detailed characterization of the resulting electrocoated Poly (CzEMA)/CFME thin films was studied by various techniques, i.e., cyclic voltammetry (CV), Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The effects of initial monomer concentrations (1, 3, 5, and 10 mM) during the preparation of modified electrodes were examined by EIS. Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode-Magnitude, and Bode-phase plots. Variation of capacitance values by initial monomer concentration and specific capacitance values are presented. The highest specific capacitance value electrocoated polymer thin film by CV method in the initial monomer concentration of 5 mM with a charge of 52.74 mC was obtained about 424.1 μF cm−2. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
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Synthesis and electropolymerization of 9-tosyl-9H-carbazole, electrochemical impedance spectroscopic study and circuit modelling
Fibers and Polymers, 2011Co-Authors: Murat Ates, Nesimi Uludag, A. Sezai SaracAbstract:This work reports on the newly synthesized 9-tosyl-9 H -carbazole (TsCz) monomer. Capacitive properties of the electrochemically grown homopolymer, poly(TsCz) film on carbon fibre microelectrode (CFME), are characterised by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Different monomer concentrations (1, 3 and 10 mM) were used for electrodeposition in 0.1 M sodium perchlorate (NaClO_4)/acetonitrile (ACN) solution. The capacitive behaviour of modified CFMEs was defined via Nyquist, Bode-Magnitude and Bode-phase plots. An equivalent electrical circuit R(CR)(QR)(CR) for different concentrations of poly(TsCz)/CFME was proposed and experimental data were simulated to obtain the numerical values of the circuit components. The Nyquist plot for poly(TsCz) shows the highest specific capacitance (50.0 mF cm^−2) at frequency of 0.01 Hz in the initial monomer concentration of 10 mM.
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Monomer concentration effect on electrochemically modified carbon fiber with poly[1‐(4‐methoxyphenyl)‐1H‐pyrrole] as microcapacitor electrode
Advances in Polymer Technology, 2009Co-Authors: A. Sezai Sarac, Murat Ates, Sibel Sezgin, Metehan C. TurhanAbstract:In this study, films of poly[1-(4-methoxyphenyl)-1H-pyrrole] [poly(MPPy)] were electrochemically grown on carbon fiber microelectrodes (CFMEs) in 0.05 M of tetraethyl ammonium perchlorate–dichloromethane. The effect of different monomer concentrations (range = 1–10 mM) on electrochemical properties of resulting polymers was characterized by cyclic voltammetry, Fourier transform infrared reflectance-attenuated total reflection spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy. All modified CFMEs were found to have capacitance on the basis of Nyquist, Bode-Magnitude, Bode-phase, and Admittance plots. An equivalent circuit model of (R(C(R(QR)))(CR)) gave the best fit for all monomer concentrations used. Furthermore, SEM and AFM results showed that poly(MPPy) was formed as a continuous and well-adhered film onto CFME. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:120–130, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20152
