scholarly journals Electrochemical oxidation of 2,4,6-trichlorophenol on iron-doped nanozirconia ceramic

2020 ◽  
pp. 78-78
Author(s):  
Nadica Abazovic ◽  
Tatjana Savic ◽  
Tatjana Novakovic ◽  
Mirjana Comor ◽  
Zorica Mojovic
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Oxidation ◽  
Electrode Surface ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Hydroxyl Group ◽  
Iron Ions ◽  
Iron Doped

Solvothermaly synthesized zirconium oxide nanopowders, pure and doped with various amounts of iron ions (1 - 20 %), were used as modifiers of glassy carbon electrode. The modified electrodes were tested in the reaction of electrochemical oxidation of 2,4,6-trichlorophenol (TCP) in order to investigate the influence of doping on electrochemical performance of zirconia matrix. The techniques of cyclic voltammetry and electrochemical impedance spectroscopy were employed. Cyclic voltammetry showed that electrooxidation of TCP proceeded through oxidation of hydroxyl group. Possible pathway included formation of quinones and formation of polyphenol film on the electrode surface leading to the electrode fouling. Iron doping enhanced the activity of zirconia matrix towards TCP electrooxidation. Electrochemical impedance spectroscopy showed the importance of iron content in zirconia matrix for preferable pathway of TCP electrooxidation. Quinone formation pathway was favored by low iron doped zirconia (doped with 1% of iron), while polyphenol film formation on the electrode surface was more pronounced at samples with higher iron ion content (for doping with 10 and 20 % of iron). The sample with 5 % of added iron ions, showed intermediate behavior where formed polyphenol film showed slight degradation.

scholarly journals Investigation of Electrochemical Behaviour of Quercetin on the Modified Electrode Surfaces with Procaine and Aminophenyl in Non-Aquous Medium

2008 ◽  
Vol 5 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Ibrahim Ender Mulazimoglu ◽  
Erdal Ozkan
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Glassy Carbon ◽  
Electrode Surface ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Carbon Electrode ◽  
Amine Group ◽  
Tetrabutylammonium Tetrafluoroborate

In this study, cyclic voltammetry and electrochemical ımpedance spectroscopy have been used to investigate the electrochemical behaviour of quercetin (3,3′,4′,5,7-pentahydroxyflavone) on the procaine and aminophenyl modified electrode. The modification of procaine and aminophenyl binded electrode surface with quercetin was performed in +0,3/+2,8 V (for procaine) and +0,4/+1,5 V (for aminophenyl) potential range using 100 mV s-1scanning rate having 10 cycle. A solution of 0.1 M tetrabutylammonium tetrafluoroborate in acetonitrile was used as a non-aquous solvent. For the modification process a solution of 1 mM quercetin in 0.1 M tetrabutylammonium tetrafluoroborate was used. In order to obtain these two surface, a solution of 1 mM procaine and 1 mM nitrophenyl diazonium salt in 0.1 M tetrabutylammonium tetrafluoroborate was used. By using these solutions bare glassy carbon electrode surface was modified. Nitrophenyl was reduced to amine group in 0.1 M HCl medium on the nitrophenyl modified glassy carbon elelctrode surface. Procaine modified glassy carbon electrode surface was quite electroactive. Although nitrophenyl modified glassy carbon elelctrode surface was electroinactive, it was activated by reducing nitro group into amine group. For the characterization of the modified surface 1 mM ferrocene in 0.1 M tetrabutylammonium tetrafluoroborate for cyclic voltammetry and 1 mM ferricyanide/ferrocyanide (1:1) mixture in 0,1 M KCl for electrochemical impedance spectroscopy were used.

scholarly journals Phenol Removal from Wastewaters by Electrochemical Biosensor

2019 ◽  
pp. 24-32
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Biosensor ◽  
Electrochemical Impedance ◽  
Experimental Results ◽  
Phenol Oxidation ◽  
Phenol Removal ◽  
Natural Phosphate ◽  
The Matrix

The aim of this work is to introduce bacteria into the matrix of natural phosphate to catalyze the phenol oxidation in the wastewater.This electrode, designated subsequently by bacteria-NP-CPE, Showed stable response and was characterized with voltammeter methods, as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and DRX. The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants in the wastewater.

scholarly journals Degradation Phenomena of Bismuth-Modified Felt Electrodes in VRFB Studied by Electrochemical Impedance Spectroscopy

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Jonathan Schneider ◽  
Eduard Bulczak ◽  
Gumaa El-Nagar ◽  
Marcus Gebhard ◽  
Paul Kubella ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Impregnation Method ◽  
Carbon Felt ◽  
Half Cell ◽  
Negative Side ◽  
Prolonged Contact ◽  
Before And After

The performance of all-V redox flow batteries (VRFB) will decrease when they are exposed to dynamic electrochemical cycling, but also when they are in prolonged contact with the acidic electrolyte. These phenomena are especially severe at the negative side, where the parasitic hydrogen evolution reaction (HER) will be increasingly favored over the reduction of V(III) with ongoing degradation of the carbon felt electrode. Bismuth, either added to the electrolyte or deposited onto the felt, has been reported to suppress the HER and therefore to enhance the kinetics of the V(II)/V(III) redox reaction. This study is the first to investigate degradation effects on bismuth-modified electrodes in the negative half-cell of a VRFB. By means of a simple impregnation method, a commercially available carbon felt was decorated with Bi 2 O 3 , which is supposedly present as Bi(0) under the working conditions at the negative side. Modified and unmodified felts were characterized electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode setup. Surface morphology of the electrodes and composition of the negative half-cell electrolyte were probed using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (TXRF), respectively. This was done before and after the electrodes were subjected to 50 charge-discharge cycles in a battery test bench. Our results suggest that not only the bismuth catalyst is dissolved from the electrode during battery operation, but also that the presence of bismuth in the system has a strong accelerating effect on electrode degradation.

scholarly journals Chiral Discrimination of Tryptophan Enantiomers via (1R, 2R)-2-Amino-1, 2-Diphenyl Ethanol Modified Interface

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Juan Zhou ◽  
Qiao Chen ◽  
Li-lan Wang ◽  
Yong-hua Wang ◽  
Ying-zi Fu
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Chiral Discrimination ◽  
Characteristic Analysis ◽  
Tryptophan Enantiomers ◽  
Sensitive Property ◽  
The Stability ◽  
Relative Change

The paper reported that a simple chiral selective interface constructed by (1R, 2R)-2-amino-1, 2-diphenyl ethanol had been developed to discriminate tryptophan enantiomers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the characteristic analysis of the electrode. The results indicated that the interface showed stable and sensitive property to determine the tryptophan enantiomers. Moreover, it exhibited the better stereoselectivity for L-tryptophan than that for D-tryptophan. The discrimination characteristics of the chiral selective interface for discriminating tryptophan enantiomers, including the response time, the effect of tryptophan enantiomers concentration, and the stability, were investigated in detail. In addition, the chiral selective interface was used to determine the enantiomeric composition of L- and D-tryptophan enantiomer mixtures by measuring the relative change of the peak current as well as in pure enantiomeric solutions. These results suggested that the chiral selective interface has the potential for enantiomeric discrimination of tryptophan enantiomers.

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