• Bulletin of the Korean Chemical Society
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• 제10권3호
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• pp.302-308
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• 1989

Species selective spectroelectrochemistry (SSSE) is described by relating the derivative absorbance (dA/dt) signals with electrochemical currents for conventional transient electrochemical experiments. Expressions relating the currents with the dA/dt signals were obtained. From these expressions, physical constants such as coefficients and molar absorptivities of electrogenerated species can be determined. By obtaining both derivative absorbance and current signals concurrently and comparing them, one can perform the SSSE experiments. The utility of the SSSE in sorting out electrochemical information is demonstrated.

• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.33-37
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• 2021

In electrochemical glucose sensing, the enhancement of the sensitivity and the response time is essential in developing stable and reliable sensors, especially for continuous glucose monitoring. We developed a method to increase the sensitivity and to shorten the response time for the sensing upon the appropriate addition of single wall carbon nanotube onto the osmium polymer-based hydrogel electrode. Also, the background stabilization is dramatically enhanced.

• 한국표면공학회지
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• 제54권3호
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• pp.158-163
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• 2021

Some studies on electrochemical additive manufacturing of metals were summarized in this technical report, and development status of selective electrochemical 3D printing technology was introduced. In order to apply it to the PCB mass production process, essential considerations how to overcome the fundamental problems, such as the sizing, process sequence and PCB process design have been described.

• Journal of Electrochemical Science and Technology
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• 제4권2호
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• pp.57-60
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• 2013

Nickel is a good electrocatalytic metal and nickel electrodes find many applications in different electrochemical fields. The nickel plated electrodes were prepared by electro-deposition technique on mild steel surface modified with in-situ deposition of nickel titanate. The SEM images shows that the nickel plating on nickel titanate modified mild steel shows better adherence than the nickel plating on bare mild steel surfaces. The extent of polarization of the nickel plating on mild steel with nickel titanate was lower than that of nickel plating on mild steel. The incorporation of nickel titanate on mild steel surface before nickel plating enhances physical, chemical and electrochemical properties of the plating film.

• Journal of Electrochemical Science and Technology
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• 제4권2호
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• pp.61-70
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• 2013

Corrosion inhibition of carbon steel in 2M HCl by some benzohydrazide derivatives (I-III) was studied using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques at $30^{\circ}C$. Polarization studies showed that all the investigated compounds are of mixed type inhibitors. Temperature studies revealed a decrease in efficiency with rise in temperature and corrosion activation energies increased in the presence of the hydrazide derivatives, probably implying that physical adsorption of cationic species may be responsible for the observed inhibition behavior. Electrochemical impedance studies showed that the presence of benzohydrazide derivatives decreases the double layer capacitance and increases the charge transfer resistance. The adsorption of these compounds on carbon steel surface was found to obey Temkin's adsorption isotherm. Synergistic effects increased the inhibition efficiency in the presence of halide additives namely KI and KBr. An inhibition mechanism was proposed in terms of strongly adsorption of inhibitor molecules on carbon steel surface.

• Carbon letters
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• 제12권3호
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• pp.180-183
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• 2011

Li metal is accepted as a good counter electrode for electrochemical impedance spectroscopy (EIS) as the active material in Li-ion and Li-ion polymer batteries. We examined the existence of signal noise from a Li-metal counter quantitatively as a preliminary study. We suggest an electrochemical cell with one switchable electrode to obtain the exact impedance signal of active materials. To verify the effectiveness of the switchable electrode, EIS measurements of the solid electrolyte interphase (SEI) before severe $Li^+$ intercalation to SFG6 graphite (at > ca. 0.25 V vs. Li/$Li^+$) were taken. As a result, the EIS spectra without the signal of Li metal were obtained and analyzed successfully for the following parameters i) $Li^+$ conduction in the electrolyte, ii) the geometric resistance and constant phase element of the electrode (insensitive to the voltage), iii) the interfacial behavior of the SEI related to the $Li^+$ transfer and residence throughout the near-surface (sensitive to voltage), and iv) the term reflecting the differential limiting capacitance of $Li^+$ in the graphite lattice.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.133.1-133.1
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• 2010

In this work, carbon black(CBs)-embed multi-walled carbon nanotubes (MWNTs) as conductive fillers for activated carbon(ACs)-based electrodes for supercapacitor were prepared by chemical reduction of oxidized MWNTs and CBs. The effect of CBs-MWNT composites on electrochemical performances of ACs-based electrodes were investigated as a function of CB-MWNT ratio. It was found that CBs-MWNTs composites were formed by the reduction reaction of the functional groups of oxidized MWNTs and CBs. It was resulted in the conjugation of CBs onto the MWNT having high surface area and aspect ratio, leading to the enhanced electrical properties of MWNTs. The electrochemical performances, such as current density, charge-discharge, and specific capacitance of the ACs/CBs-MWNT electrodes were higher than that of ACs/MWNTs and conventional ACs/CB electrodes, which was attributed to the synergistic effect of CBs-MWNTs as a conductive filler.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.243.1-243.1
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• 2010

Devices based on nanomaterials platforms are emerging as a powerful tool for ultrasensitive sensors for the direct detection of biological and chemical species. In this talk, we will report the preparation and the full characterization of electrochemical polymerization of biopolymers platforms and nano-structure formation for electrochemical detection of enzymatic activity and toxic compound in electrolyte for biosensor applications. Formation of an electroactive polymer film of two different compounds has been quantified by observing new redox peak at higher potentials in cyclic voltammogram measurements. RCT value of at various biopolymer concentration based hybrid films has been obtained from electrochemical impedance spectroscopy analysis and possible mechanism for formation of complexes during electrochemical polymerization on conducting substrates has been investigated. Biosensors developed based on these hybrid biopolymers have very high sensitivity.

• 대한화학회지
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• 제58권2호
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• pp.160-168
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• 2014

The electrochemical behavior and corrosion inhibition of zinc in 0.5 M $H_2SO_4$ in the absence and presence of some chromones has been investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The presence of these investigated compounds in the corrosive solutions decrease the weight loss, the corrosion current density, and double layer capacitance but increases the charge transfer resistance. Polarization studies were carried out at room temperature, and showed that all the studied compounds act as mixed type inhibitors with a slight predominance of cathodic character. The effect of temperature on corrosion inhibition has been studied and the thermodynamic activation and adsorption parameters were determined and discussed. The adsorption of the investigated compounds on zinc was found to obey Langmuir adsorption isotherm.

• Corrosion Science and Technology
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• 제3권1호
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• pp.1-5
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• 2004

A polarization resistance is generally used to estimate the corrosion rate in the corrosion monitoring by an electrochemical impedance method. When the Faradaic impedance has a time constant due to the reaction intermediate, the electrochemical impedance describes more than one loop on the complex plane. For example, the electrochemical impedance of iron in acidic solution shows capacitive and inductive loops on the complex plane. In this case, the charge transfer resistance and the polarization resistance are determined at middle and low frequency ranges, respectively. Which should be selected for corrosion resistance in corrosion monitoring, the charge transfer resistance or the polarization resistance'? In the present paper, the above-mentioned question is examined theoretically and experimentally.