• Nano
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• v.13 no.12
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• pp.1850140.1-1850140.9
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• 2018

An electrochemical sensor ($Cu^{2+}$-IIPs/GCE) was developed for detection of $Cu^{2+}$ in water. $Cu^{2+}$-IIPs/GCE was prepared by dispersing $Cu^{2+}$ imprinted polymers ($Cu^{2+}$-IIPs) on a preprocessed glassy carbon electrode. $Cu^{2+}$-IIPs were synthesized on the surface of modified carbon spheres by ion imprinting technology. The electrochemical performance of $Cu^{2+}$-IIPs/GCE was evaluated by differential pulse voltammetry method. The response of $Cu^{2+}$-IIPs/GCE to $Cu^{2+}$ was linear in $1.0{\times}10^{-5}mol/L$ to $1.0{\times}10^{-3}mol/L$. The detection limit was $5.99{\times}10^{-6}mol/L$ (S=N = 3). The current response value of $Cu^{2+}$-IIPs/GCE was 2.14 times that of the nonimprinted electrode. These results suggest that $Cu^{2+}$-IIPs/GCE can detect the concentration of $Cu^{2+}$ in water, providing a new way for heavy metal ions adsorption and testing.

• Journal of the Korean Electrochemical Society
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• v.10 no.2
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• pp.126-131
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• 2007

The durability problem of Prussian blue in non-aqueous $Li_+$-based electrolytes has been due to the degradation of the Prussian blue electrode matrix during the insertion/extraction processes by $Li_+$. In this work, we designed and synthesised the Prussian blue without reducing the electrochromic performance in non-aqueous $Li_+$-based electrolytes. Prussian blue was electrodeposited on a glass which has ITO coating, and the coating solution is a mixture solution of $FeCl_3\;and\;K_3Fe(CN)_6$ with deionized water added HCl, KCl, and LiCl, respectively. The durability of Prussian blue was evaluated by an in-situ transmittance measurement during a continuous and pulse potential cycling test, and measured by electroactive layer thickness due to evaluating the degradation.

• Journal of the Korean Electrochemical Society
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• v.3 no.4
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• pp.241-245
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• 2000

The objective of this work Is to design, fabricate, and characterize pseudo-capacitor using amorphous $MnO_2\;nH_2O$ electrode material. The cyclic voltammogram under 100mV/s scan rate of the material shows the electrochemically stable potential window of 1V and the specific capacitance of 250F/g. The TDMA pulse test result indicates that the TDMA system (2 parallel-pseudo-capacitor systems) has the ohmic voltage drop of 0.22V and the capacitor voltage drop of 0.38V. The total voltage drop of the TDMA system is 0.60V and less than 1V of which value is the maximum voltage drop requirement or the TDMA satellite phone. Also, the TDMA system had the ESR of $55m{\Omega}$ and the capacitance of 105mF. Therefore, it is confirmed that the TDMA system has the application feasibility as load-leveling capacitor for the satellite phone.

• The Journal of Natural Sciences
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• v.7
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• pp.37-46
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• 1995

Electrochemical behavior of $Ln^{3+},$-ALC complexes($Gd^{3+},$ $Tb^{3+},$ $Dy^{3+},$ $Ho^{3+},$ $Er^{3+},$ $Yb^{3+}$ and $Lu^{3+}$-alizarin complex-one) has been investgated by d.c polarography, differential pulse polarography and cyclic voltammetry. The reduction mechanism of ALC comes to the conclusion that the two electron make one step of reversible processes, and that there is few adsorption in the electrode reaction. The new complex is made from one lanthanide ion and one ALC. This complex is proven to make an adsorptive complex wave, by the experiments of differential pulse polarography and cyclic voltammetry. The reduction potential of complex wave($P_2$)turns up more negatively than ligand wave($P_1$) does. Linear calibration curves of the decreasing P1 and increasing $P_2$ is obtained when the lanthanide concentration varys from $2.5X10^5$M to $1X10^4M$.

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.276-281
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• 2009

Electrochemical behaviors of $U^{3+}$ and $Gd^{3+}$ were investigated in LiCl-KCl eutectic molten salt by using various electrochemical techniques. The electrodeposition and dissolution currents for uranium show the maximum at -1.51V and -1.35V, respectively while, for gadolinium,at -2.15V and -1.9V, respectively. In case of LiCl-KCl molten salt containing both of $U^{3+}$ and $Gd^{3+}$, the peak potential of electrodeposition of gadolinium shifts to more positive potential than in the solution without $U^{3+}$. The potentials in chronopotentiometric data suddenly dropped to negative value as soon as the reduction currents were applied and became constant at the potential around which the $U^{3+}$ and $Gd^{3+}$ are electrodeposited. The results of normal pulse voltammetry (NPV) and square wave voltammetry show that those methods can be used to qualitatively analyze the elements in the melts. Especially, the differentiation of NPV result was found to be useful for the separation of the peaks of which potentials are close each other.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.40-46
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• 2006

Square wave voltammetric (SWV) and cyclic voltammetric (CV) behaviors of cefotaxime sodium and ceftriaxone sodium have been investigated in the potential range between -0.10 V and -1.30 V using the phosphate buffers of various pH values ($2.00{\sim}9.10$). Two main peaks observed were irreversible and protons were involved in their electrochemical reductions. The first peaks of these cephalosporin antibiotics are due to the reduction of the azomethine double bond in the methoxyimino group of the side chain at position 7. The second peaks of cefotaxime sodium and ceftriaxone sodium are related to the reductions of the ${\Delta}^3$ double bond and the dioxo moiety of the side chain at position 3, respectively. The calibration curve of cefotaxime sodium in the concentration range between $1.0{\times}10^{-7}M$ and $1.0{\times}10^{-5}M$ yielded the linearity with the correlation coefficient of 0.9998 when the first peak of the antibiotic in a phosphate buffer of pH 3.02 was measured at the conditions of frequency of 120 Hz and pulse height of 50 mV by SWV. The present fast, simple and accurate SWV assay method was applied to determine cefotaxime sodium in the commercial antibiotic powder of injection.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.57-65
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• 1995

The electrochemical reduction of methylene blue (MB) in 1.0${\times}$10-2 M KNO3 aqueous solution was investigated by direct current (DC), differential pulse (DP) polarography, cyclic voltammetry (CV) and controlled potential coulometry (CPC). The electrode reduction of melthylene blue was processed CE reaction mechanism by two electrons transfer at the first reversible wave (- 0.18 volts vs. Ag/AgCl). MB was strongly adsorbed on the stationary mercury electrode and the reduction product of conptrolled potential electrolysis was rapidly auto-oxidized in air to the original methylene blue. Upon the basis of interpretation of cyclic voltammogram with pH change, possible CE electrode reaction mechanism was suggested.

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.121-126
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• 2010

An amperometric ascorbic acid selective sensor utilizing the transfer reaction of proton liberated from the dissociation of ascorbic acid in aqueous solution across an elliptic micro-hole water/organic gel interface is demonstrated. This redox inactive sensing platform offers an alternative way for the detection of ascorbic acid to avoid a fouling effect which is one of the major concerns in redox based sensing systems. The detection principle is simply measuring the current change with respect to the assisted transfer of protons by a proton selective ionophore (e.g., ETH 1778) across the micro-hole interface between the water and the polyvinylchloride-2-nitrophenyloctylether gel phase. The assisted transfer reaction of protons generated from ascorbic acid across the polarized micro-hole interface was first characterized using cyclic voltammetry. An improved sensitivity for the quantitative analysis of ascorbic acid was achieved using differential pulse stripping voltammetry with a linear response ranging from 1 to $100\;{\mu}M$ concentrations of ascorbic acid. As a demonstration, the developed sensor was applied for analyzing the content of vitamin-C in different types of commercial pharmaceutical tablets and syrups, and a satisfactory recovery from these samples were also obtained.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.33-39
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• 1999

Electrochemical behaviors of $Sm^3+$-ARS complexes has been investigated by d.c.polarography, differential pulse polarography and cyclic voltammetry. $Sm^3+$forms 1 : 3 adsorptive complexes with ARS.The reduction potential of complex wave $(P_2)$ shifted more negatively than the ligand wave $(P_1)$. The linear calibration curves of decreasing $P_1$ and increasing $P_2$ is obtained when $Sm^3+$ concentration varies from TEX>$2{\times}10^{-6}$ M to $3.2{\times}10^{-5}$ M.

• Analytical Science and Technology
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• v.13 no.2
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• pp.173-178
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• 2000

A new open-chain ligand containing two phenol groups, 1, 14-Bis (2-hydroxybenzyl)-2, 6, 9, 12-tetraazatetradecane(bsated) was synthesized as its tetrahydrochloride salt and characterized by elemental analysis, mass, infrared and NMR. Its proton dissociation constants ($logK^n{_H}$) and stability constants ($logK_{ML}$) toward $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ were determined at $25^{\circ}C$ and 0.10M($KNO_3$) ionic strength in aqueous solution by potentiometry. The X-ray structure of its copper (II) complex [Cu(bsated)]$(ClO_4)_2$ was reported: Monoclinic space group $P2_1/n$, $a=17.856(4){\AA}$, $b=17.709(1){\AA}$, $c=8.539(2){\AA}$, $V=2700(2){\AA}$ with Z=4. Electrochemical studies of [Cu(bsated)]$(ClO_4)_2$ complex in dimethyl sulfoxide (DMSO) solution containing tetrabutylammonium perchlorate (supporting electrolyte) were carried out by cyclic voltammograms (CV) and normal pulse voltammetry (NPV).