• Journal of Energy Engineering
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• v.20 no.2
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• pp.77-83
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• 2011

It is requested to improve negative electrode of Ni-Zn battery for industrial application. Ni-Zn battery has main problems not to commercialize because of short life cycle, heavy gassing and fast electrolyte vaporization so far. It has been studied on 8 cells performances under promoting electric, additional materials and binders changed. With these materials($Ca(OH)_2$, $Bi_2O_3$), negative electrolyte can be manufactured equal and tight as well as low gassing. Furthermore, to supply EG-EP#12(gravity 1.26), keeping stable electrolyte gravity in battery, the life cycle of Ni-Zn battery is extremely improved 200~300% than initial performance.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.438-442
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• 2013

In the present work, electroless plating was used for coating thin films consisting mainly of Ni and P on carbon fiber. Structural changes appeared upon the post-annealing at various temperatures of the Ni-P film on carbon fiber was studied using various analysis methods. Scanning, a flat surface structure of Ni-P film on carbon fiber was found after electroless plating of Ni-P film on carbon fiber without post-annealing, whereas annealing at $350^{\circ}C$ resulted the formation of porous structures. With increasing the annealing temperature to $650^{\circ}C$ with an interval of $50^{\circ}C$, the pore size increased, but the density decreased. X-ray diffraction (XRD) showed the existence of metallic Ni, and Ni-P compounds before post-annealing, whereas the post-annealing resulted in the appearance of NiO peaks, and the decrease in the intensity of the peak of metallic Ni. Using X-ray photoelectron spectroscopy (XPS), phosphorous oxides were detected on the surface upon annealing at $650^{\circ}C$, and $700^{\circ}C$, which can be attributed to the phosphorous compounds originally existing in the deeper layers of the Ni films, which undergo sublimation and escape from the film upon annealing. Escape of phosphorous species from the bulk of Ni-P film upon annealing could leave a porous structure in the Ni films. Porous materials can be of potential applications in diverse fields due to their interesting physical properties such as high surface area, and methods for fabricating porous Ni films introduced here could be easily applied to a large-scale production, and therefore applicable in diverse fields such as environmental filters.

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1029-1038
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• 2008

Transition-metal-oxide-incorporated hydrotalcites were prepared by hydrothermal reaction of their synthetic mixtures containing precursors of transition metal oxides and their properties of nitrogen dioxide adsorption was investigated. The dispersion of transition metal oxides on the hydrotalcites and the amount and the state of nitrogen dioxide adsorbed on them were examined by using XRD, SEM, XPS, nitrogen adsorption, a gravimetric adsorption system, FT-IR spectroscopy and temperature programmed desorption techniques. Transition metal oxides were mainly incorporated on their surface and the incorporation of iron and nickel oxides to the hydrotalcites increased their adsorption amounts of nitrogen dioxide. The dispersion of iron oxide on the hydrotalcites was effective in increasing the amount of nitrogen dioxide adsorption, while too much amount of iron oxide incorporation reduced the amount of nitrogen dioxide adsorption due to masking of surface basic sites by agglomerated iron oxide. Although the incorporation of iron oxide to the hydrotalcites lowered the adsorption strength of nitrogen dioxide, the incorporation of it with a proper amount enhanced the amount of nitrogen dioxide adsorption and the stability against the hydrothermal treatment.

• Journal of the Korean institute of surface engineering
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• v.49 no.4
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• pp.382-388
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• 2016

NiO nanoparticles were synthesized by hydrothermal method for the application to ethanol gas sensor. They were composited with $Co_3O_4$ nanoparticles to improve the sensitivity to ethanol gas. Scanning electron microscopy revealed that the synthesized NiO nanoparticles were plate-shaped with the approximate size and thickness of 60 - 120 nm and 20 nm, respectively. On the other hand, $Co_3O_4$ nanoparticles mixed with NiO was observed to be spherical with the size range of 30 - 50 nm. The sensitivities of NiO sensors composited with $Co_3O_4$ nanoparticles at an optimal ratio of 8 : 2 were enhanced to approximately 1.44 - 1.79 times as high as those of as-synthesized NiO sensors for the ethanol concentration of 10 - 200 ppm at $200^{\circ}C$. The mechanism of the improved ethanol gas sensing of the NiO sensors composited with $Co_3O_4$ nanoparticles was discussed.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1203-1207
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• 2018

In this study, silica nanowires were formed using silicon oxide films with different oxygen contents, and their microstructure and physical properties were compared with those of silica nanowires formed using Si wafers. The silicon oxide films were fabricated by using a plasma-enhanced chemical vapor deposition method. Silica nanowires were formed by thermally annealing silicon oxide films coated with nickel films as a catalyst. In the case of silicon oxide films having an oxygen content of approximately 50 at.% or less, the formation mechanism, microstructure, and physical properties of the nanowires were not substantially different from those of the silicon wafer. In particular, the uniformity of the thickness showed better behavior in the silicon oxide films. These results imply that silicon oxide films can be used as an alternative for fabricating high-quality silica nanowires at low cost.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.27-32
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• 1986

Electrical conductivities of NiO-$Y_2O_3$ systems containing 0.8, 1.6, and 3.2 mol% NiO have been measured in the temperature range of 400 to 1100$^{\circ}$C at $PO_2$'s of 1 ${\times}10^{-5}$ to 2 ${\times}10^{-1}$ atm. Plots of $log\sigma$ vs 1/T at constant $PO_2$'s are found to be linear with an inflection at temperature around 650$^{\circ}$C. The slopes are steeper in the high temperature region above 650$^{\circ}$C than in the low temperature region below 650$^{\circ}$C. The average activation energies are 41.8kcal/mol in the high temperature region and 12.5kcal/mol in the low temperature region. $PO_2$'s dependence value, 1/n, is 1/5.1~1/5.4 in the high temperature region and 1/5.9~1/6.2 in the low temperature region. The NiO-$Y_2O_3$ systems are found to be an electronic p-type semiconductor. The predominant defects in the systems are believed to be triply ionized yttrium vacancy in the high temperature region and doubly ionized oxygen interstitial in the low temperature region. Ionic contribution to the total conductivity is found from ${\sigma}^{\propto}PO_2$ in the temperatures below 650$^{\circ}$C.

• New & Renewable Energy
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• v.4 no.2
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• pp.39-44
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• 2008

Partial oxidation of methane was carried out by ceria-promoted Ni-substituted hydrotalcite-derived catalysts ($Ce_xNi_3$-HTlc ; x=$0.3{\sim}1.2$) in a fixed-bed reactor. The Ce/Ni ratio of 0.3/3 in the catalyst showed the best catalytic activity but the Ce/Ni ratio became higher above 0.3/3, the catalyst became less active in short-term tests. No ceria promoted catalyst was started to decrease $CH_4$ conversion after 20 h but the Ce/Ni ratio 0.3/3 catalyst was kept its stability in long-term tests.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.35-41
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• 2011

Temperature programmed reduction experiments for Fe- and Co-oxides were performed and weight losses were carefully measured to calculate the extent of reduction. Addition of nickel and palladium affected the reduction by lowering the DTG peak temperature. Reduction experiments for the oxides on alumina were also studied and the effect of nickel and palladium addition was confirmed. And that was explained by means of increased adsorption of hydrogen and increased diffusion ability of the surface hydrogen.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.221-221
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• 2010

NiO 산화물 타겟을 이용한 RF 마그네트론 스퍼터 방법로 glass 기판 위에 NiO 온도를 R.T(room temperature)~$400^{\circ}C$ 변화시켜 Ar 가스만을 사용하여 박막을 증착시켜, 증착 온도에 따라 NiO 박막 특성에 미치는 영향을 조사하였다. XRD 측정으로부터 증착된 박막의 결정구조는 $200^{\circ}C$이하에서 (111) 면의 우선 배향성으로 보이다가 $300^{\circ}C$ 이상에서 (220)의 우선 배향성으로 보이는 다결정 입방구조임을 확인하였다. NiO 박막의 전기적 특성의 변화는 기판의 온도가 $200^{\circ}C$까지는 $10^5\;{\Omega}cm$대를 보였고 기판의 온도가 $300^{\circ}C$ 이상에서는 $10^{-2}{\sim}10^{-1}{\Omega}cm$대로 감소하는 것을 관측하였다. 이러한 ${\sim}10^7$ 정도의 큰 저항 변화를 관측하였고, 전기적 변화 특성을 결정성, 결정립의 변화 및 NEXAFS를 통한 밴드 구조 변화 등으로 설명하였다.

• Corrosion Science and Technology
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• v.11 no.3
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• pp.96-102
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• 2012

Outer diameter stress corrosion cracking (ODSCC) has occurred for Alloy 600 (Ni 75 wt%, Cr 15 wt%, Fe 10 wt%) as a heat exchanger tube of the steam generator (SG) in nuclear power plants (NPP) during long term operation. Among many causes for SCC, lead (Pb) is known to be one of the most deleterious species in the secondary system. In the present work, the oxide formed on Alloy 600 was characterized as a function of the PbO content in 0.1 M NaOH at $315^{\circ}C$ by using an electrochemical impedance spectroscopy (EIS), a transmission electron microscopy (TEM), equipped with an energy dispersive x-ray spectroscopy (EDS). The oxide property was analyzed in view of SCC susceptibility.