• Title/Summary/Keyword: $Ni(OH)_2$

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촉매에 따른 셀룰로오스로부터의 수소 발생량 변화

  • Gang, In-Cheol;Han, Jae-Gil;Zhang, Qiwu;Saito, Fumio
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.50.1-50.1
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    • 2009
  • 셀룰로오스를 Ca(OH)2와 Ni(OH)2를 Pot에 넣고 동시에 밀링 공정을 실시한 후, 열을 가함으로써 수소를 얻었다. X-ray diffraction (XRD), thermogravimetry/ mass spectrometry (TG/MS), gas chromatography (GC) 장비를 이용해 수소 발생량 및 촉매의 역할에 관하여 실험하였다. 촉매 Ni(OH)2를 대신한 NiO 또는 Ni를 사용했을 경우 사용된 촉매에 따른 수소의 발생량의 차이를 보였는데 이는 촉매의 사이즈가 수소 발생량과 관련이 있음을 보여주었다. 한편, Ca(OH)2를 대신하여 Li(OH)를 사용하였을 때 수소 발생 온도가 약$400\sim500\;^{\circ}C$ 범위에서 $350\sim400\;^{\circ}C$의 범위로 낮아져 보다 낮은 온도에서 수소 회수가 가능하였다. 이때 발생한 CO와 CO2는 수 ppm정도로 적은 양이었다.

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Growth Kinetics and Electronic Properties of Passive Film of Nickel in Borate Buffer Solution (Borate 완충용액에서 니켈 산화피막의 생성 과정과 전기적 성질)

  • Kim, Younkyoo
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.9-16
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    • 2014
  • In a borate buffer solution, the growth kinetics and the electronic properties of passive film on nickel were investigated, using the potentiodynamic method, chronoamperometry, and single- or multi-frequency electrochemical impedance spectroscopy. The oxide film formed during the passivation process of nickel has showed the electronic properties of p-type semiconductor, which follow from the Mott-Schottky equation. It was found out that the passive film ($Ni(OH)_2$) of Ni formed in the low electrode potential changes to NiO and NiO(OH) while the electrode potential increases.

Electrochemical Properties of LiNiO$_2$/Li cell (LiNiO$_2$/Li cell의 전기화학적 특성)

  • 전대규;김철중;성창호;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.279-282
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    • 1997
  • The propose of this study is research and improvement of LiNiO$_2$as cathode material for Lithium secondary batteries. LiNiO$_2$is prepared by heating LiOH . $H_2O$ and Ni(OH)$_2$(mole ratio 1 : 1) on various heat condition. In the result of XRD mesurement, all LiNiO$_2$prepared at this study showed hexagonal structure. In Cyclic Voltammetry, LiNiO$_2$is not conspicous about oxidation peak but oxidation curve change steeply over 3.8V and reduction peak discover at 3.6V. In discharge capacities, specific capacity is higher $O_2$than air when preliminary heated and 75$0^{\circ}C$ than $700^{\circ}C$, 80$0^{\circ}C$ when heated. Therefore, when preliminary heat at $650^{\circ}C$ $O_2$and heat at 75$0^{\circ}C$ carried out, discharge property is the best.

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Surface observation of Ni(OH)2 nanosheets fabricated by electrodeposition method (전착법에 의해 제작된 Ni(OH)2 나노 시트의 표면 관찰 및 분석)

  • Kim, Dong Yeon;Son, Injoon;Choi, Mun-Hyun
    • Journal of the Korean institute of surface engineering
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    • v.54 no.3
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    • pp.152-157
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    • 2021
  • The pseudocapacitor has a high energy density characteristic because it accumulates charges through a paradic redox reaction. However, due to its strong insulation properties, metal hydroxides should be designed as structural systems optimized for charge transfer to support fast electron transport. Also, Nickel material is weak to heat and is easily deformed when used as a cathode material, so stability must be secured. In this study, nickel hydroxide was produced by electrodeposition to secure the stability of nickel. Electrodeposition is a synthetic method suitable for growing optimized nickel hydroxide because it allows fine control. Nickel hydroxide (Ni(OH)2) is a metal hydroxide used as a pseudocapacitor anode due to its high capacitance, electrical conductivity and resistance. Therefore, in order to determine how Ni(OH)2 nanosheets are formed and what are the optimization conditions, various measurement methods were used to focus on structural growth of nanosheets produced by electrodeposition.

Adsorption Behaviors of Nickel ton on the Waste Pulp Produced in the Paper Recycling Process (고지(古紙) 재생(再生) 과정(過程)에서 발생(發生)하는 폐(廢)펄프를 흡착제(吸着劑)로 이용(利用)한 니켈 폐수(廢水) 처리(處理) 특성(特性))

  • Baek, Mi-Hwa;Shin, Hyun-Young;Kim, Dong-Su
    • Resources Recycling
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    • v.15 no.3 s.71
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    • pp.58-65
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    • 2006
  • The applicability of the waste pulp which produced in the paper recycling process as an adsorbent for the treatment of $Ni^{2+}$ ion in wastewater has been investigated taking the initial concentration of adsorbate, temperature, the amount of adsorbent, and solution pH as the experimental variables. In addition, the effect of the concentration of coexisting solute and pre-treatment of adsorbent on the adsorbability of $Ni^{2+}$ ion were also examined. The electrokinetic potential of waste pulp was observed to be positive below pH 7.8 and negative above this pH. The adsorption reaction of $Ni^{2+}$ ion reached its equilibrium within 4 hours after the reaction was initiated and the adsorbed amount of adsorbate was found to increase with its initial concentration. The adsorbability of $Ni^{2+}$ was raised with temperature so that its adsorption reaction was considered to be exothermic, which was substantiated by thermodynamic calculation. Also, the adsorbed amount of $Ni^{2+}$ was raised with the amount of waste pulp and with pH in the range of pH $3{\sim}6$. This behavior of the adsorption of $Ni^{2+}$ according to the solution pH was well agreed with the electrokinetic characteristics of waste pulp in solution. The amount of coexisting solute was observed to reversely affect on the $Ni^{2+}$ adsorption onto waste pulp under the experimental conditions. With regard to the pre-treatment of adsorbent with NaOH, the adsorbability of $Ni^{2+}$ was increased with the concentration of NaOH to a certain extent. However, it was found to decrease contrarily when the concentration of NaOH became too high.

A Polarographic Study of Nickel-Monoethanolamine Complex (Ni-Monoethanolamine 착염의 폴라로그라피-)

  • Son, Byung-Yung;Yang, Jae-Hyun
    • Journal of the Korean Chemical Society
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    • v.9 no.3
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    • pp.121-123
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    • 1965
  • Polarographic studies of Ni(II) ion complexed with monoethanolamine, MEA, in aqueous solution have been carried out using sodium perchlorate as a supporting electrolyte. With use of D. C. and A. C. polarograms polarographic behaviors of the complex have been discussed. The wave obtained from basic solutions are found to be well defined and reversible, while reduction of the complex at pH smaller than 8.8 seems to be kinetic controlled with different complex species. Reducing species of the complex on the mercury electrode is determined to be $Ni(MEA)_3OH$ instead of $Ni(MEA)_2(OH)_2$ which is reported by other workers. Overall stability constant of $Ni(MEA)_3OH$ is obtained to be $10^{20}.$

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