Cyclic Voltammetry of Iodine at the Organic Liquid/Aqueous Solution Interface

2007 ◽  
Vol 72 (7) ◽  
pp. 917-926 ◽  
Author(s):  
Shaoai Xie ◽  
Jinping Jia ◽  
Hong-Jin Chen

The electrochemical behavior of iodine extracted with an organic solvent at the liquid/liquid interface was studied using a new composite electrode. The effects of various solvents and supporting electrolyte on the electrochemical reaction of iodine were analyzed by cyclic voltammetric curves. The formation of a polar solvent complex of iodine and a strong donor solvent in organic solution was comfirmed by UV-VIS spectra. A possible mechanism was suggested based on experiments. This method makes it possible to measure heavy metal ion in solution indirectly.

Author(s):  
Agnieszka Nosal-Wiercińska ◽  
Marlena Martyna ◽  
Sławomira Skrzypek ◽  
Anna Szabelska ◽  
Małgorzata Wiśniewska

AbstractThe paper discusses the electroreduction of Bi(III) ions in the aspect of expanding the “cap-pair” effect.The “cap-pair” rule is associated with the acceleration of the electrode’s processes by organic substances. The interpretation of the “cap-pair” effect mechanism was expanded to include the effect of supporting electrolyte concentration on the acceleration process and the type of electrochemical active as well as used protonated organic substances. It has also been shown that the phenomena occurring at the electrode/solution interface can influence a change in the dynamics of the electrode’s process according to the “cap-pair” rule.


2005 ◽  
Vol 3 (1-2) ◽  
pp. 43-53 ◽  
Author(s):  
Ivana Šestáková ◽  
Tomáš Navrátil

The application of voltammetric methods using different rates of polarisation on HMDE reveal inert or labile behaviour of Cd- or Zn- complexes in the presence of excessive cadmium or zinc ions in solution. This phenomenon was demonstrated first on the simplest phytochelatin – complex of peptide(γ-Glu-Cys)2Glywith cadmium, later on rabbit liver metallothioneins –Cd7MTin the presence of cadmium andCd5Zn2MTin the presence of zinc. Voltammetric methods can distinguish between labile and inert complexes present simultaneously and therefore could elucidate their role in reactions of metal ion transfer.Another method using different rates of polarisation – elimination voltammetry with linear scan – proved that S-tetracoordinated complexes of Cd(II) or Zn(II) in the above-mentioned metallothioneins on HMDE are reduced in the adsorbed state. This implies the possibility of increasing the sensitivity of identification or determination of the above complexes. On carbon composite electrode, similar behaviour of Cd-complexes as on HMDE was observed using differential pulse voltammetry.


2019 ◽  
Vol 37 (3-4) ◽  
pp. 205-216 ◽  
Author(s):  
Yujie Zhang ◽  
Quanqin Xue ◽  
Fei Li ◽  
Jizhe Dai

A polypyrrole/chitosan composite material was obtained by chemical polymerization. The adsorption performance of a hot-molded polypyrrole/chitosan composite electrode was tested by adsorption/desorption experiments. Scanning electron microscopy and Fourier-transform infrared spectroscopy both showed the deposition of polypyrrole on the chitosan surface. The specific capacitance of the polypyrrole/chitosan composite was determined by cyclic voltammetry in 1.0 M KCl at 0.01 V/s as 102.96 F/g. The adsorption/desorption experiments indicated that the specific adsorption capacity of the composite for Cu2+ was 99.67 mg/g, while the removal performance for other metal ions, such as Ag+, Pb2+, and Cd2+, was good. The results of multicycle adsorption/desorption tests showed that the adsorption rate of the polypyrrole/chitosan composite electrode for Cu2+ was decreased from 56.4 to 51.4% over 10 cycles, demonstrating the stable metal-ion adsorption/desorption behavior of the composite electrode. The obtained performances show that the prepared polypyrrole/chitosan composite material is an ideal electrode material for the removal of heavy metal ions.


2014 ◽  
Vol 37 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Taj Al Tanvir ◽  
Md Elius Hossain ◽  
Mohammad Al Mamun ◽  
MQ Ehsan

Complex of iron(III) with saccharin, [Fe(C7H4O3SN)2Cl] has been prepared in aqueous medium. The IR and electronic spectral analysis suggest that two saccharin molecules are attached to the metal ion through N atom and there is no chemically coordinated or crystalline water in the complex molecule. The magnetic moment value indicates the paramagnetic character of the complex. The cyclic voltammetric study indicates a quasi-reversible electron transfer process due to the presence of iron in the compound. DOI: http://dx.doi.org/10.3329/jbas.v37i2.17560 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 2, 195-203, 2013


2020 ◽  
Vol 32 (10) ◽  
pp. 2541-2544
Author(s):  
Pirim Setiarso ◽  
Firma Inggriani

A graphene oxide-nanozeolite composite was prepared and empolyed as electrode for cyclic voltammetric analysis of aspirin. Graphene oxide was synthesized with the improved Hummer method, while nanozeolite synthesized using a mechanical ball milling method. Cyclic voltammetric analysis of aspirin was influenced by several factors viz. the composition of working electrode, pH, deposition time and scan rate. The optimized parameters of graphene oxide-nanozeolite composite electrode has the best composition at a ratio of 3:2:5 at pH of solution 4, deposition time at 5 s and scan rate at 100 mV s-1. A recovery percentage of 99.61% having limit detection of electrode was 0.0611 ppm (0.002 mM).


2014 ◽  
Vol 18 (12) ◽  
pp. 1093-1100 ◽  
Author(s):  
Geani Maria Ucoski ◽  
Shirley Nakagaki ◽  
Fábio Souza Nunes

Cyclic voltammetry and thin-layer spectroelectrochemical properties of the free base 5,10,15,20-tetrakis(1,3-benzodioxole)porphyrin ( H 2 P ), and its manganese and iron complexes ( MnP and FeP , respectively) were studied in dichloromethane with tetra-butyl ammonium hexafluorophosphate (TBAPF6) as supporting electrolyte. The free base undergoes two monoelectronic oxidations at +0.71 and +0.96 V vs.  Ag / Ag +, corresponding to the formations of the π-cation radical and dication. Two reductions were observed at -1.53 and -1.87 V corresponding to the formation of π-anion and dianion species. The cyclic voltammograms of the Mn III and Fe III complexes also showed a reversible process centered in the metal ion with E1/2 values at -0.61 and -0.59 V, respectively. In a typical experiment, in situ spectroelectrochemical response showed a decrease of the Soret band at 422 nm, a red shift of the Q-bands, and the new low intensity bands between 800–950 nm range. Structural features and spectroscopic assignments were proposed and discussed based on semi-empirical (molecular mechanics MMFF and ZINDO/S (Zerner method of intermediate neglect of differential overlap for spectroscopy) calculations.


1975 ◽  
Vol 30 (5-6) ◽  
pp. 350-354 ◽  
Author(s):  
Sudhindra Swarup Sharma ◽  
Mukhtar Singh

The reduction of Zn(II) at the d.m.e. has been studied in aqueous mixtures of formamide and dimethylformamide. The general polarographic characteristics have been determined, using 0.1 M NaNO3 as the supporting electrolyte. The reduction of Zn(II) in these organic solvents is irreversible and diffusion controlled. The kinetic parameters, αna and kf,h have been calculated separately by KOTECKY and DELAHAY treatments. The change of polarographic characteristics and kinetic parameters is explained in terms of solvation of the metal ion in these solvents. The electrocapillary curves in the presence of these solvents have also been studied.


2013 ◽  
Vol 662 ◽  
pp. 266-272 ◽  
Author(s):  
Dai Fen Chen ◽  
Qi Ce Zeng ◽  
Huan Huan He ◽  
Liang Wei ◽  
Zi Dong Yu

As the fabrication technology of the composite electrode becomes sophisticated, the understanding of the detailed knowledge of the microstructure’s effect on the electrochemical process is essential for the commercializing of the solid oxide fuel cell (SOFC). In this paper, an equivalent circuit for the SOFC structure is proposed to clearly describe the electronic electric current transfer process, ionic electric current transfer process and the charge transfer process at the electrochemical reaction interface between electronic and ionic conducting materials. And types of the boundary condition setting constraints for the developing of the multi-physics coupling numerical model of SOFC are obtained basing on the electrochemical kinetic analysis.


1970 ◽  
Vol 24 (2) ◽  
pp. 158-164 ◽  
Author(s):  
Aftab Ali Shaikh ◽  
M Badrunnessa ◽  
Jannatul Firdaws ◽  
Md Shahidur Rahman ◽  
Nishat Ahmed Pasha ◽  
...  

The electrochemical redox behavior of Cu(II) has been investigated at glassy carbon electrode (GCE) in Britton-Robinson (BR) buffer as well as in a mixture of BR buffer and potassium chloride media. It is apparent that BR buffer can act as a supporting electrolyte and modify the electrochemical behavior of Cu(II) ion in aqueous medium. In BR buffer medium, Cu(II) undergoes one two-electrons redox process, while in a mixture of BR buffer and KCl media it follows two one-electron electrochemical reaction routes. Because of the formation of hydrogen bridge bond between the supporting electrolyte and GCE surface, the Cu(II) ion follows Cu(II)/Cu(0) electrochemical reaction path, while in presence of KCl such a hydrogen bridge bond is not formed and it undergoes successive Cu(II)/Cu(I) and Cu(I)/Cu(0) electrode reaction processes. Moreover, the linear variation of peak current with the square root of scan rate indicates that the electrochemical redox processes are diffusion controlled. Keywords: Supporting electrolytes; Britton-Robinson buffer; Cu-reduction; Peak current DOI: http://dx.doi.org/10.3329/jbcs.v24i2.9704 Journal of Bangladesh Chemical Society, Vol. 24(2), 158-164, 2011


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