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Kang Sam-Woo;Park Chong-Min;Chang Choo-Hawn;Do Lee-Mi;Suh Moo-Yul
- Journal of the Korean Chemical Society
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- v.37 no.1
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- pp.83-91
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- 1993
The eletrochemical behavior of light lanthanide complexes has been investigated by several electrochemical techniques in alkaline solutions. The composition of the complexes was determined by spectrophotometric method to be 1 : 1 and reduction mechanism was two steps 1 electron transfer reaction. The half wave potential of first peak depended on pH and cathodic current showed remarkably adsorptive properties. The results of DC and CV investigation demonstrated the quise-reversible nature of the electron transfer. The anion radical formed after first one electron reduction process, dimerizes to form dimer. The apparent irreversible behavior of the second wave is a result of the existence of a fast protonation following the second electron transfer. An exhaustive electrolysis was carried out at controlled potential of -1.80 V, deep blue color of the solution became progressively weaker, and then the solution became colorless solution. The final product of an exhaustive electrolysis is electro-inactive. The appearance of four steps may be explained by the fact the reduction of Ln-OCP elucidated ECEC mechanism.
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Kim, Geon-Sik;Yang, Jae-Ho;Gang, Gi-Won;Lee, Yeong-U;Song, Geun-U;Jeong, Yeon-Ho
- Proceedings of the Korean Nuclear Society Conference
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- 2004.10a
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- pp.1043-1044
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- 2004
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Kim, Chang-Sam;Kang, Seung-Min
- Journal of the Korean Crystal Growth and Crystal Technology
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- v.19 no.5
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- pp.246-250
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- 2009
The Ni formation behavior from the reduction of NiO nano crystals in the $H_2/N_2$ gas mixtures. The NiO nano crystals were synthesized by heat-treating nickel nitrate$(Ni(NO_3)_2\cdot6H_O)$ in the air at $500^{\circ}C$, and had an octahedral shape and the particle size of 200~500 nm. The NiO nano-crystals had well-developed (111) planes which is hardly formed in normal synthetic conditions. The reduction process was carried out at 300 and $600^{\circ}C$ for 15 and 60 minutes, respectively. When the NiO nano-crystals were reduced at $300^{\circ}C$, the Ni particles sustained the same octahedral shape as NiO, while Ni particles were to agglomerate at $600^{\circ}C$.
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Yu, Yeon-Tae;Kim, Chi-Kwon
- Korean Journal of Materials Research
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- v.11 no.2
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- pp.76-81
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- 2001
In order to recover Au and Pd from the leaching solution of various electronic wastes by electrowinning, the electrochemical behavior of Au and Pd in hydorchloric acidic solution was investigated by means of voltammetry. The reduction potential of Au ion was 800mV and the limiting current appeared at 470mV in electrolytic solution of gold. The reduction potential of Pd ion was 500mv and the limiting current appeared at 150mV in electrolytic solution of Palladium. However, in Au-Pd electrolytic solution, the Potentials for reduction and the limiting current of Au decreased as the content of Pd in electrolyte increased, and the potentials for the limiting current of Au and Pd closed nearest together when percentage of Pd electrolytic solution was 37v71% in Au-Pd electrolyte.
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Kang, Sam-Woo;Pak, Chong-Min;Do, Lee-Mi;Song, Myoung-Kyu;Kim, Il-Kwang
- Analytical Science and Technology
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- v.7 no.3
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- pp.361-369
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- 1994
Voltammetric behavior of some light lanthanide ions($La^{3+}$, $Pr^{3+}$, $Nd^{3+}$, $Sm^{3+}$ and $Eu^{3+}$) in acetonitrile(AN) and dimethylformamide(DMF) has been investigated by direct current, differential pulse polarography and cyclic voltammetry. The reduction of $La^{3+}$, $Pr^{3+}$ and $Nd^{3+}$ in 0.1M TEAP proceeded directly to the metallic state through three-electron charge transfer of irreversible process where as $Sm^{3+}$ and $Eu^{3+}$ proceeded by charge transfer of two steps. As the results of the cyclic voltammetric investigation, the first step reduction of $Sm^{3+}$ and $Eu^{3+}$ were a quasireversible reaction, the second step reductions were an irreversible reaction. The cathodic peak currents of the differential pulse polarogram showed adsorptive properties at lower sweep rates and high concentrations of these metal ions. The peak potenital was shifted to a negative petential and the peak current decreased with the increase of percentage of water in AN. On the other hand, the peak potential was shifted to a positive potential and the peak current decreased with an increased percentage of water in DMF.
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