• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.663-668
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• 2021

For the development of highly efficient quantum dot-sensitized solar cells (QDSCs), it is important to enhance the electrocatalytic activity of the counter electrodes (CEs). Herein, a fabrication process of Cu₂S CEs are optimized for the development highly efficient QDSCs. The surface of brass film is treated with HCl solution to prepare the Cu₂S CEs, and the concentraion as well as the temperature of HCl solution are controlled. It is found that the uniformity for the thickness of prepared Cu₂S CEs is enhanced when the diluted HCl solution is used, compared to the HCl solution of standard concentration. In addition, the electrocatalytic activity of the Cu₂S CEs is also increased with the modificed process, which is confirmed by impedance data and Tafel polarization curves. As a result, the photoconversion efficiency of QDSCs is improved from 4.49% up to 5.73%, when the concentraion and temperature of the HCl treatment are efficiently optimized.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.78-82
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• 2023

The oxygen evolution reaction (OER) is the primary challenge in renewable energy storage technologies, specifically electrochemical water splitting for hydrogen generation. We report effects of Mo doping into Ni layered double hydroxide (Ni-LDH) microcrystal on electrocatalytic activities. In this study, Mo doped Ni-LDH were grown on three-dimensional porous nicekl foam (NF) by a facile solvothermal method. Homogeneous LDH structure on the NF was clearly observed. However, the surface microstructure of the nickel foam began to be irregular and collapsed when Mo precursor is doped. Electrocatalytic OER properties were analyzed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Mo doping used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Mo amount introduced into the Ni LDH was discussed with respect to their OER performance.

• Analytical Science and Technology
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• v.26 no.1
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• pp.42-50
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• 2013

This paper describes the electrocatalytic activity for the oxidation of small biomolecules on the surface of Pt-Ru nanoparticles supported by $TiO_2$-hollow sphere prepared for use in sensor applications or fuel cells. The $TiO_2$-hollow sphere supports were first prepared by sol-gel reaction of titanium tetraisopropoxide with poly(styrene-co-vinylphenylboronic acid), PSB used as a template. Pt-Ru nanoparticles were then deposited by chemical reduction of the $Pt^{4+}$ and $Ru^{3+}$ ions onto $TiO_2$-hollow sphere ($Pt-Ru@TiO_2-H$). The prepared $Pt-Ru@TiO_2-H$ nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and elemental analysis. The electrocatalytic efficiency of Pt-Ru nanoparticles was evaluated via ethanol, methanol, dopamine, ascorbic acid, formalin, and glucose oxidation. The cyclic voltammograms (CV) obtained during the oxidation studies revealed that the $Pt-Ru@TiO_2-H$ nanocomposites showed high electrocatalytic activity for the oxidation of biomolecules. As a result, the prepared Pt-Ru catalysts doped onto $TiO_2$-H sphere nanocomposites supports can be used for non-enzymatic biosensor or fuel cell anode electrode.

• 한국전기화학회:학술대회논문집
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• 1998.10a
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• pp.19-19
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• 1998

• 한국전기화학회:학술대회논문집
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• 2004.04a
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• pp.26-26
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• 2004

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1842-1844
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• 2002

• Bulletin of the Korean Chemical Society
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• v.19 no.7
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• pp.795-797
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• 1998

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.251-255
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• 2010

We report on the electrocatalytic reduction of hydrogen peroxide at nanoporous gold (NPG) surfaces. Various NPG surfaces with different surface structure were prepared by changing the conditions of electrodeposition for Ag-Au layers such as the concentration ratios of $KAu(CN)_2$ over $KAg(CN)_2$ and deposition charges. The effects of different electrochemical conditions on the electrocatalysis of $H_2O_2$ reduction were investigated. The NPG surfaces exhibited sensitive amperometric responses for $H_2O_2$ reduction, from which calibration plots with higher sensitivity than a bare Au surface were obtained.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1171-1174
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• 2007

We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.248-256
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• 2020

In this study, pyrocatechol violet (Pcv) is proposed for the first time as an efficient electrocatalyst for oxidation of sulfide and flow injection analysis (FIA) of sulfide. A graphite pencil electrode (GPE) was modified with Pcv via immersion of the GPE into 0.01 M Pcv solution for 15 min. Cyclic voltammograms (CVs) demonstrated that Pcv/GPE exhibits a good electrocatalytic performance due to shift in the potential from +400 at bare GPE to +70 mV at Pcv/GPE and obtaining an enhancement in the peak current compared with the bare GPE. A linear range between 0.25 and 250 μM sulfide with a detection limit of 0.07 μM was obtained from the recorded current-time curves in Flow Injection Analysis (FIA) of sulfide. Sulfide in water samples was also successfully determined using the proposed FI amperometric methods.