• 제목/요약/키워드: PT-Ir

검색결과 182건 처리시간 0.031초

전기도금법에 의한 백금 흑 수광체 제조 (Preparation of Pt-Black Absorber by Electroplating)

  • 배성호;이상만;이문호
    • 한국결정학회지
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    • 제7권2호
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    • pp.133-146
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    • 1996
  • 전기 도금법으로 제조한 백금흑의 형상과 적외선 흡수특성을 XRD, SEM, IR 분광기를 사용하여 조사하였다. 금(Au)이 입혀진 알루미나 유리기판 위에 pH 1.0∼1.5에서 1∼5분동안 백금층을 입혔는데, 염화백금과 아세트산 납으로 제조한 용액을 전해액으로 사용하였다. 전류밀도가 20∼50 mA/㎠일 때 백금흑은 수지상으로 성장하여 "나무"와 같은 형태를 보였다. 백금흑의 면적밀도가 1.3mg/㎠ 이상일 때 10μm의 적외선에서 측정한 수광효율은 90% 이상이었다.

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Synthesis and Characterization of Phosphorescent Platinum and Iridium Complexes of 6-Chloro-3-phenylpyridazine

  • Lee, Sang-Jin;Seok, Kang;Lee, Jae-Sung;Lee, Seung-Hee;Hwang, Kwang-Jin;Kim, Young-Kwan;Kim, Young-Sik
    • Journal of Photoscience
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    • 제10권2호
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    • pp.185-187
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    • 2003
  • The preparation and the photophysics of organometallic Pt(II) and Ir(III) complexes with 6-ch1oro-3-phenylpyridazine (H6Clppdz) are reported. $K_2$PtCl$_4$ and IrCl$_3$ㆍn$H_{2}O$ cleanly cyclometalate with H6Clppdz, forming the corresponding chloro-bridged dimers, (6Clppdz)Pt($\mu$-Cl)$_2$Pt(6Clppdz) and (6Clppdz)$_2$Ir($\mu$-Cl)$_2$Ir(6Clppdz)$_2$ in good yield. These chloro-bridged dimers are cleaved with acetylacetone (Hacac) to give the corresponding monomer, (6Clppdz)Pt(acac) and (6Clppdz)$_2$ Ir(acac), respectively. Both complexes show bright orange luminescence at room temperature and the emission wavelengths are different depending on the metal and the structure of complexes. (6Clppdz)Pt(acac) shows two sharp emission bands in shorter wavelength ($\lambda$$_{em}$=541 and 580 nm), while (6Clppdz)$_2$ Ir(acac) shows a broad emission band in longer wavelength ($\lambda$$_{em}$=615 nm). Strong spinorbit coupling due to the heavy metal atom allows for the formally forbidden mixing of the $^1$MLCT with the $^3$MLCT and $^3$$\pi$-$\pi$$^{*}$ states.

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Effects of Diffusion Layer (DL) and ORR Catalyst (MORR) on the Performance of MORR/IrO2/DL Electrodes for PEM-Type Unitized Regenerative Fuel Cells

  • Choe, Seunghoe;Lee, Byung-Seok;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
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    • 제8권1호
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    • pp.7-14
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    • 2017
  • This study aims to examine the influences of substrates/diffusion layers (DL) and oxygen reduction reaction catalysts ($M_{ORR}$) on the performance of $M_{ORR}/IrO_2$/DL-type bifunctional oxygen electrodes for use in polymer electrolyte membrane (PEM)-type unitized regenerative fuel cells (URFC). The $M_{ORR}/IrO_2$/DL electrodes were prepared via two sequential steps: anodic electrodeposition of $IrO_2$ on various DLs and fabrication of $M_{ORR}$ layers (Pt, Pd, and Pt-Ru) by spraying on $IrO_2/DL$. Experiments using different DLs, with Pt as the $M_{ORR}$, revealed that the roughness factor of the DL mainly determined the electrode performance for both water electrolyzer (WE) and fuel cell (FC) operations, while the contributions of porosity and substrate material were insignificant. When Pt-Ru was utilized as the $M_{ORR}$ instead of Pt, WE performance was enhanced and the electrode performance was assessed by analyzing round-trip efficiencies (${\varepsilon}_{RT}$) at current densities of 0.2 and $0.4A/cm^2$. As a result, using Pt-Ru instead of Pt alone provided better ${\varepsilon}_{RT}$ at both current densities, while Pd resulted in very low ${\varepsilon}_{RT}$. Improved efficiency was related to the additional catalytic action by Ru toward ORR during WE operation.

$IrO_2$를 하부전극으로 사용한 $Sr_{0.9}Bi_{2+x}Ta_2O_9$ 박막의 유전 및 전기적 특성 (Dielectric and Electrical Properties of $Sr_{0.9}Bi_{2+x}Ta_2O_9$ Thin Films on $IrO_2$ Electrode)

  • 박보민;송석표;정병직;김병호
    • 한국세라믹학회지
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    • 제37권3호
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    • pp.233-239
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    • 2000
  • Sr0.9Bi2+xTa2O9(x=0, 0.1, 0.2, 0.3) thin films on IrO2/SiO2/Si or Pt/Ti/SiO2/Si substrate were prepared by spin coating method using SBT stock solutions synthesized by MOD process. SBT thin films on IrO2 transformed to layered perovskite phase at $700^{\circ}C$, but showed low breakdown voltage due to their porous microstructure. The smaple of Sr0.9Bi2+xTa2O9 composition showed the best dielectric and electrical properties. When the sample of the same composition was annealed at 80$0^{\circ}C$, the dielectric and electric properties were improved due to the grian growth and dense surface. the remanent polarization values(2Pr) at $\pm$3 V for IrO2 and Pt electrodes were 10.5, 7.15$\mu$C/$\textrm{cm}^2$, respectively. The SBT thin film with IrO2 electrode showed the lower coercive field. The leakage current density and breakdown voltage of SBT thin films on IrO2 were higher than those on Pt.

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MOD 법으로 제조한 강유전성 SBT 박막에서 하부전극이 유전 및 전기적 특성에 미치는 영향 (Effects of Bottom Electrode to Dielectric and Electrical Properties of MOD Derived Ferroelectric SBT Thin Films)

  • 김태훈;송석표;김병호
    • 한국전기전자재료학회논문지
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    • 제13권8호
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    • pp.694-699
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    • 2000
  • S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ solutions was synthesized by MOD (metalorganic decomposition) method. SBT thin films with 2000$\AA$ thickness were prepared on Ir $O_2$/ $SiO_2$/Si and Pt/Ti/ $SiO_2$/Si substrates using the spin coating process and then investigated the dielectric and electrical properties of them. In the case of using Ir $O_2$bottom electrode the hysteresis loop was saturated at lower temperature than Pt/Ti electrode but the breakdown phenomenon was occurred at low voltage because of the rough surface morphology and porous microstructure of SBT thin films. As the results of the fatigue and imprint characteristics related to the lifetime and reliability of devices after 10$^{10}$ cycles the fatigue rates were about 10% at the Ir $O_2$and Pt/Ti bottom electrodes. Both SBT thin films with Ir $O_2$ and with Pt/Ti bottom electrodes show a slight tendency to imprint after 10$^{9}$ cycles but do not lead to a failure.e.e.

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Determination of the Frumkin and Temkin Adsorption Isotherms of Underpotentially Deposited Hydrogen at Pt Group Metal Interfaces Using the Standard Gibbs Energy of Adsorption and Correlation Constants

  • Chun, Jinyoung;Jeon, Sang K.;Chun, Jang H.
    • 전기화학회지
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    • 제16권4호
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    • pp.211-216
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    • 2013
  • At Pt(111), Pt(100), Pt, and Rh interfaces, the Frumkin adsorption isotherm of underpotentially deposited hydrogen (UPD H) and related electrode kinetic data are determined using the standard Gibbs energy of adsorption. The Temkin adsorption isotherm of UPD H correlating with the Frumkin adsorption isotherm of UPD H is readily determined using the correlation constants between the Temkin and Frumkin or Langmuir adsorption isotherms. At the Pt(111), Pt(100), Pt, and Rh interfaces, the lateral repulsive interaction between the UPD H species is interpreted using the interaction parameter for the Frumkin adsorption isotherm. The lateral repulsive interaction between the UPD H species at the Pt(111), Pt(100), Pt, and Rh interfaces is significantly different from the lateral attractive interaction between the overpotentially deposited hydrogen (OPD H) species at Pt, Ir, and Pt-Ir alloy interfaces.