• Korean Journal of Materials Research
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• v.15 no.4
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• pp.271-274
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• 2005

We investigated the crystalline and electrical properties of ZnO thin films for transparent electrode as a function of the oxygen pressures during the deposition. The ZnO thin films were deposited on a flexible teflon substrates by the pulsed laser deposition. From the X-ray diffraction, ZnO films showed c axis oriented ZnO(0002) crystal structure. The FWHM (full width at half maximum) values decreased from $0.51^{\circ}\;to\;0.34^{\circ}$ as the oxygen pressure increased from 0.1 mTorr to 10.0 mTorr showing the improvement of crystallinity. The resistivity and hall mobility of ZnO film deposited at the oxgen pressure of 0.1 mTorr at $200^{\circ}C$ was about $5\times10^{-4}\Omega{\cdot}cm\;and\;20cm^2/V{\cdot}s$, respectively. The optical transmittance of the ZnO films on flexible teflon substrate was found to be above $85\%$.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.148-155
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• 2015

Electrospun $LaCoO_3$ perovskite nanofibers were produced for the air electrode in Zn-air rechargeable batteries using electrospinning technique with sequential calcination. The final calcination temperature was varied from 500 to $800^{\circ}C$ in order to determine its effect on the physical and electrochemical properties of the prepared $LaCoO_3$ perovskite nanofibers. The surface area of the electrospun $LaCoO_3$ perovskite nanofibers were observed to decrease with increasing final calcination temperature. Electrospun $LaCoO_3$ perovskite nanofibers calcined with final calcination temperature of $700^{\circ}C$ had the best electrocatalytic activity among the prepared perovskite nanofibers.

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.76-81
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• 2016

An anatase TiO₂ nanotube array (NTA) was fabricated by anodization and successive heat treatments. When the anatase TiO₂ NTA was cathodically polarized, its color changed to blue, and it could be used as an electrochemically active anode for an oxygen evolution reaction (OER) in alkaline water electrolysis. The structure of the blue anatase TiO₂ NTA was controlled by the anodization conditions and its catalytic activity increased with an increase of the surface area. The activity of the blue anatase TiO₂ NTA gradually reduced with the continued OER because of the partial oxidation of Ti³⁺ to Ti⁴⁺. However, an intermittent cathodic regeneration process could significantly slow its reduction rate. The blue anatase TiO₂ NTA could be an alternative anode for alkaline water electrolysis.

• Korean Journal of Materials Research
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• v.13 no.10
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• pp.640-644
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• 2003

NiCr thin films were fabricated by rf magnetron sputtering for applying to both the top electrode and absorption layer on Pb(Zr, Ti)O$_3$(PZT) thin films for infrared sensors. The rms roughness and resistivity of NiCr films prepared with Ni power of 80 W and Cr power of 50 W showed the most stable oxidation resistance after annealing at $600^{\circ}C$ for 5 min in oxygen ambient. The rms roughness and resistivity of NiCr films annealed at $V^{\circ}C$ in oxygen ambient were about 2$0\AA$ and $70 \mu$Ω-cm, respectively. As-deposited Ni/PZT/Pt and NiCr (Ni 80 W, Cr 50 W)/PZT/Pt structures showed well saturated hysteresis loops. However, in case of the samples annealed at $500^{\circ}C$ in oxygen ambient, only NiCr/PZT/Pt showed saturated loops having a remanent polarization of 20$\mu$C/$\textrm{cm}^2$. Ultra-thin NiCr films showed a possibility as a top electrode for infrared sensors.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.324-329
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• 2004

Oxygen diffuses through the cation-specific membrane, reducing the coulomb yield of the fuel cell. In the present study, attempts were made to enhance current generation from the fuel cell by lowering the oxygen diffusion, including the uses of ferricyanide as a cathode mediator and of a platinum-coated graphite electrode. Ferricyanide did not act as a mediator as expected, but as an oxidant in the cathode compartment of the microbial fuel cell. The microbial fuel cell with platinum-coated graphite cathode generated a maximum current 3-4 times higher than the control fuel cell with graphite cathode, and the critical oxygen concentration of the former was 2.0 mg $1^{-1}$, whilst that of the latter was 6.6 mg $1^{-1}$. Based on these results, it was concluded that inexpensive electrodes are adequate for the construction of an economically feasible microbial fuel cell with better performance as a novel wastewater treatment process.

• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.132-137
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• 2010

This study is concerned the electrocatalytic generation of oxygen gas at electrochemically deposited manganese oxide electrode in KOH solution. Manganese oxide nanoparticles electrodeposited onto relatively substrate, e.g glassy carbon, Au, Ti electrode. MnOx is electrodeposited in nanorod structure which cover the overall surface of the substrate. The $\gamma$-MnOOH that is kind of manganese oxide species plays a significant role as a catalytic mediator, which promote 4-electron reduction process. Modified electrodes with electrodeposited manganese oxide structures resulted in significant decrease in the anodic polarization compared with the unmodified electrodes in alkaline media.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.77-82
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• 2015

Ozone is a powerful disinfectant and oxidizing agent, and it is used in a wide range of applications, such as waste water treatment, food processing, etc.. There is also a great potential of using ozone in new emerging medical applications, such as ozone dentistry and ozone oxygen therapy. For these purposes, simple, small, compact and efficient sources of ozone are needed. In this study, in order to increase the current-voltage range of the discharge and to avoid the overheating of the gas in the ozonizer we suggested ozonizer of injection needle and plate electrode type(INP Type) with the gas through the needle. A ozonizer of INP type have been investigated by focusing on ozone concentration and yield according to flow rates and Gap of two electrodes. The results of studies of ozone production for DC corona discharge in oxygen at atmospheric pressure about the ozonizer of INP type. The ozone concentration and the generation yield increased as the gap of two electrodes and gas flow were decreased. Also, when the gap of two electrodes and gas flow with no change, the ozone concentration and generation yield each have variation of direct proportion and inverse proportion with discharge voltage.

• Journal of the Korean Ceramic Society
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• v.37 no.8
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• pp.817-823
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• 2000

A solid-state electrochemicall cell for sensing CO2 gas was fabricated using a solid electrolyte of Li2CO3-Li3PO4-Al2O3 mixture and a reference electrode of LiMn2O4. The e.m.f. (electromotive force) of sensor showed a good accordance with theoretical Nernst slope (n=2) for CO2 gas concentration range of 100-10000 ppm above 35$0^{\circ}C$. The e.m.f. of sensor was constant regardless of oxygen partial pressure at the high temperature above 0.1 atm. It was, however, a little depended on oxygen partial pressure as the pressure decreased below 0.1 atm. The oxygen-dependency of our sensor gradually disappeared as the operating temperature increased. The sensing behavior of our CO2 sensor was affected by the presence of water vapor, but its effect was small comparing with other sensors.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.45-45
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• 2000

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.240-240
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• 2010

In this paper, in these case of photoelectrode using UV treatment after oxygen solar conversion efficiency is increased. According to oxygen injection UV treatment will removal residual organics and increase the TiO2 surface area but also UV treatment can affect the same chemical action of ozone treatment. More porous networks and larger porosities were obtained in the TiO2 films prepared UV treatment after oxygen injection.