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cyclic-voltammetry
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Multistep reduction of oxygen on polycrystalline silver in alkaline solution
, Article Cuihua Xuebao/Chinese Journal of Catalysis ; Volume 31, Issue 5 , 2010 , Pages 541-546 ; 02539837 (ISSN) ; Gobal, F ; Mahjani, M. G ; Hosseini Aliabadi, M ; Sharif University of Technology
Abstract
Oxygen reduction on a polycrystalline silver electrode was studied by cyclic voltammetry and electrochemical impedance spectroscopy. The reaction occurred by a two-electron pathway. The steps in the mechanism were observed in the cyclic voltammograms recorded with different scan rates. The intermediates formed in the steps were detected by electrochemical impedance spectroscopy
Investigation of the electrochemical behavior of catechol and 4-methylcatechol in the presence of methyl mercapto thiadiazol as a nucleophile: application to electrochemical synthesis
, Article Journal of Applied Electrochemistry ; Volume 40, Issue 1 , 2010 , Pages 115-122 ; 0021891X (ISSN) ; Rastgar, S ; Sharif University of Technology
Abstract
The present study concerns the electrochemical behavior of catechol and 4-methylcatechol in the presence of 2-mercapto-5-methyl-1,3,4-thiadiazole (MMT) in aqueous medium on the surface of the glassy carbon electrode by means of cyclic voltammetry and controlled-potential coulometry. The oxidation mechanism was deduced from voltammetric and spectrophotometric data. The electro-generation of quinoid intermediates and their subsequent Michael-type reaction with MMT has been investigated as a clean and convenient strategy for the synthesis of corresponding reaction products. In addition, electro-synthesis of Michael addition products has been successfully accomplished by controlled-potential...
The pH effects on the capacitive behavior of nanostructured molybdenum oxide
, Article Journal of Solid State Electrochemistry ; Volume 14, Issue 4 , 2010 , Pages 681-686 ; 14328488 (ISSN) ; Gobal, F ; Raissi, H ; Moghiminia, S ; Sharif University of Technology
Abstract
Nanostructured molybdenum oxide having a particle size in the range of 30-80 nm was prepared by potentiodynamic electrodeposition method, and the effects of H2SO4 concentration on its capacitive behavior were studied by cyclic voltammetry, galvanostatic discharge, and electrochemical impedance spectroscopy. Poor to fair capacitive behaviors were witnessed depending on the electrolyte concentration and conditions of charge/discharge. Increasing acid concentration to 0.02 M had favorable effect, while beyond that, the effect was detrimental. Capacitance around 600 F g-1 was recorded in the potential range of 0 to -0.55 V vs. Ag/AgCl
Voltammetric studies of Azathioprine on the surface of graphite electrode modified with graphene nanosheets decorated with Ag nanoparticles
, Article Materials Science and Engineering C ; Volume 58 , 2016 , Pages 1098-1104 ; 09284931 (ISSN) ; Iraji Zad, A ; Shahrokhian, S ; Sharif University of Technology
Elsevier Ltd
Abstract
By using graphene nanosheets decorated with Ag nanoparticles (AgNPs-G) as an effective approach for the surface modification of pyrolytic graphite electrode (PGE), a sensing platform was fabricated for the sensitive voltammetric determination of Azathioprine (Aza). The prepared AgNPs-G nanosheets were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and Raman spectroscopy techniques. The electrochemical behavior of Aza was investigated by means of cyclic voltammetry. Comparing to the bare PGE, a remarkable enhancement was observed in the response characteristics of Aza on the surface of the modified electrode (AgNPs-G/PGE) as well as a noticeable...
Deposition of (Ti, Ru)O2 and (Ti, Ru, Ir)O2 oxide coatings prepared by sol–gel method on titanium
, Article Journal of Sol-Gel Science and Technology ; Volume 79, Issue 1 , 2016 , Pages 44-50 ; 09280707 (ISSN) ; Ghorbani, M ; Sharif University of Technology
Springer New York LLC
Abstract
Titanium anodes activated by noble metal oxides possess a wide range of advantages and applications. Actually, coating of titanium anodes by highly conductive oxides of noble metals (Ru, Ir) dramatically increases the lifetime of these anodes. In this study, the binary coating consisting of Ti and Ru and the ternary coating consisting of Ti, Ru and Ir were prepared through sol–gel method. After coating of the titanium substrate, the corrosion behavior of coatings was studied by anodic polarization and cyclic voltammetry tests. The lifetime of anodes was determined using accelerated corrosion test. The morphology of coatings was examined by field emission scanning electron microscopy and...
Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone
, Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 842-850 ; 09284931 (ISSN) ; Naderi, L ; Ghalkhani, M ; Sharif University of Technology
Abstract
The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force...
Transition metal ions-doped polyaniline/graphene oxide nanostructure as high performance electrode for supercapacitor applications
, Article Journal of Solid State Electrochemistry ; 2017 , Pages 1-14 ; 14328488 (ISSN) ; Shahrokhian, S ; Zad, A. I ; Sharif University of Technology
Abstract
Polyaniline/graphene oxide (PANI/GO) co-doped with Zn2+ and Fe3+ was synthesized via a simple and low cost one-step chronoamperometry method on stainless steel (SS) as the substrate. The Fe3+-Zn2+-PANI/GO nanocomposite is characterized using X-ray diffraction as well as Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and field emission scanning electron microscopy. Also, cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy are used to study the electrochemical performance of the as-prepared electrode materials. Significantly, the Fe3+-Zn2+-PANI/GO nanocomposite exhibits a specific...
X-ray crystallographic, spectroscopic, electrochemical and computational studies on axially ligation of ZnTPP with pyridine derivative anchored to aza-crown macrocyclic ligand
, Article Polyhedron ; Volume 133 , 2017 , Pages 419-432 ; 02775387 (ISSN) ; Shahhoseini, L ; Kubicki, M ; Sharif University of Technology
Abstract
The complexes of zinc tetraphenylporphyrin (ZnTPP) with the azacrown macrocycles bearing pyridine moiety (bp, 1p) as the axial ligand were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, 1H and 13C NMR, fluorescence, UV–Vis, together with TD DFT calculations. Solution study by employing 1H NMR spectroscopy for ZnTPPbenz and ZnTPPH complexes elucidated that the pyridine moiety was bonded through the fifth-coordination site on the zinc metal atom. The observation of hypsochromic shifts of ca. 15 nm for Q(0,1) (the strongest emission) as well as ca. 15 nm for Q(0,0) (the second) bands testified to significant difference in the fluorescence of ZnTPPbenz...
Electrochemical investigation of electrodeposited platinum nanoparticles on multi walled carbon nanotubes for methanol electro-oxidation
, Article Journal of Chemical Sciences ; Volume 129, Issue 9 , 2017 , Pages 1399-1410 ; 09743626 (ISSN) ; Moakhar, R. S ; Dolati, A ; Sharif University of Technology
Abstract
Abstract: The electrodeposition of platinum nanoparticles (PtNPs) on multiwall carbon nanotubes (MWCNTs)/fluorine-doped tin oxide glass (FTO) was investigated. Nucleation and growth mechanisms were studied via Scharifker and Hills model. Chronoamperometry results clearly show that the electrodeposition processes are diffusion-controlled and the diffusion coefficient is 1.5×10-5cm2/s. The semi-spherical particles with lamellar morphology were observed in 1M H 2SO 4, while a petal shape was discerned in 0.5M H 2SO 4. Also, dispersion, size, and uniformity of PtNPs were investigated, where the finer distribution of PtNPs with the average size less than 100 nm was obtained in 0.5M H 2SO 4...
One step electrodeposition of V2O5/polypyrrole/graphene oxide ternary nanocomposite for preparation of a high performance supercapacitor
, Article International Journal of Hydrogen Energy ; Volume 42, Issue 33 , 2017 , Pages 21073-21085 ; 03603199 (ISSN) ; Shahrokhian, S ; Iraji zad, A ; Sharif University of Technology
Abstract
A new ternary nanocomposite based on graphene oxide (GO), polypyrrole (PPy) and vanadium pentoxide (V2O5) is obtained via one-step electrochemical deposition process. Electrochemical deposition of V2O5, PPy and GO on a stainless steel (SS) substrate is conducted from an aqueous solution containing vanadyl acetate, pyrrole and GO to get V2O5/PPy/GO nanocomposite. Characterization of the electrode material is carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). The electrochemical performance of the as-prepared nanocomposite is evaluated by...
A high performance supercapacitor based on graphene/polypyrrole/Cu2O-Cu(OH)2 ternary nanocomposite coated on nickel foam
, Article Journal of Physical Chemistry C ; Volume 121, Issue 12 , 2017 , Pages 6508-6519 ; 19327447 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Abstract
A simple and low-cost electrochemical deposition method is used to prepare reduced graphene oxide/polypyrrole/Cu2O-Cu(OH)2 (RGO/PPy/Cu2O-Cu(OH)2) ternary nanocomposites as the electrode material for supercapacitor application. First, graphene oxide-polypyrrole (GO/PPy) nanocomposite is electrochemically synthesized on Ni foam by electro-oxidation of pyrrole monomer in an aqueous solution containing GO and Tiron. Subsequently, the GO/PPy film is converted to the corresponding reduced form (RGO/PPy) by an effective and eco-friendly electrochemical reduction method. Then, a thin layer of Cu2O-Cu(OH)2 is formed on RGO/PPy film by chronoamperometry. The RGO/PPy/Cu2O-Cu(OH)2 nanocomposite is...
Investigation of the electrochemical behavior of tizanidine on the surface of glassy carbon electrode modified with multi-walled carbon nanotube/titan yellow–doped polypyrrole
, Article Journal of Electroanalytical Chemistry ; Volume 823 , 2018 , Pages 146-154 ; 15726657 (ISSN) ; Shamloofard, M ; Salimian, R ; Sharif University of Technology
Abstract
The present paper describes a voltammetric sensor based on glassy carbon electrode (GCE) modified with a thin film of multi-walled carbon nanotubes (MWCNTs) coated with an electro-polymerized layer of titan yellow-doped over–oxidized polypyrrole (OPPY) for the determination of tizanidine (TIZ). A significant enhancement was observed in the anodic peak current of TIZ on the surface of OPPY/CNT/GCE, relative to the bare, CNT- and OPPY-coated GCEs. The microscopic structure and surface morphology of the composite film was thoroughly characterized by means of atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. The effect of various...