• Title, Summary, Keyword: xH2O]

Search Result 2,543, Processing Time 0.057 seconds

The Photovoltaic Effect of Iodine-Doped Metal Free Phthalocyanine/ZnO System (Ⅱ). The Photovoltaic Effect of $ZnO/H_2Pc(I)_x$ Dispersed in Poly(9-vinylcarbazole) (요오드가 도핑된 무금속 프탈로시아닌/산화아연계의 광기전력 효과 (Ⅱ). Poly(9-vinylcarbazole)에 분산된 $ZnO/H_2Pc(I)_x$계의 광기전력 효과)

  • Heur, Soun-Ok;Kim, Young-Soon
    • Journal of the Korean Chemical Society
    • /
    • v.39 no.3
    • /
    • pp.176-185
    • /
    • 1995
  • To improve photosensisitizing efficiency of ZnO/$H_2Pc(I)_x$ system, ZnO/$H_2Pc(I)_x$ system was dispersed in a typical photoconductive polymer of poly(9-vinylcarbazole)(PVCZ). The iodine dopant level(x) of ZnO/${\chi}-H_2Pc(I)_x$ is proportional to concentration of iodine, whereas x of ZnO/${\beta}-H_2Pc(I)_x$ decreased from the highest x=0.97 at more than $6.3{\times}10^{-3}$ M iodine solution. The Raman spectra of ZnO/${\chi}-H_2Pc(I)_x$ at 514 nm exhibited characteristic $I_3^-$ patterns in the range of 50∼550 $cm^{-1}$ at $x{\geq}0.57.$ The surface photovoltage of ZnO/${\chi}-H_2Pc(I)_{0.48}$/PVCZ was approximately 1.6 times greater than ZnO/${\chi}-H_2 Pc(I)_{0.48}$ and was 1.8 times of ZnO/${\chi}-H_2Pc(I)_{0.57}$/PVCZ at 670 nm. With ZnO/$H_2Pc(I)_x$/PVCZ, the highest iodine dopant levels showed a higher photovoltage. Therefore the injection of holes from H2Pc into PVCZ resulted in that photosensisitizing effect of ZnO/$H_2Pc(I)_x$/PVCZ system was improved compared to ZnO/$H_2Pc(I)_x$ case.

  • PDF

Synthesis and Characterization of Substituted Pyridine Complexes of Molybdenum(Ⅴ). Di-${\mu}$-oxo-dioxodichlorobis(substituted pyridines) dimolybdenum(Ⅴ) and Substituted Pyridinium Di-${\mu}$-oxo-dioxohexaisothiocyanatodimolybdates(Ⅴ) (몰리브덴의 피리딘계 착물합성과 그 성질 (제5보). 이-${\mu}$ -옥소-이옥소이클로로비스(치환피리딘) 이 몰리브덴 (Ⅴ) 와 이-${\mu}$- 옥소-이옥소육이소티오시아나토 이 몰리브덴 (Ⅴ) 산 치환피리딘늄)

  • Kim, Chang-Su;Sang Oh Oh
    • Journal of the Korean Chemical Society
    • /
    • v.26 no.6
    • /
    • pp.383-388
    • /
    • 1982
  • $Mo_2O_4Cl_2$$(X-py)_4{\cdot}2H_2$O and $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O have been prepared. The infrared, electronic and reflectance spectra, molar conductances and magnetic susceptibility data of complexes are reported. $Mo_2O_4Cl_2$$(X-py)_4{\cdot}2H_2$O (X-py were 3-and 4-cyanopyridine, nicotinamide, 3,5-lutidine and 2-amino-4-picoline) were obtained by hydrolysis of the corresponding substituted pyridinium oxopentachloromolybdates(Ⅴ). Addition of water and substituted pyridines to molybdenum(Ⅴ)-thiocyanate ethylacetate extract yielded brown compounds, $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O where X-py were pyridine, ${\alpha}$, 3-bromopyridine 3,5-lutidine, 3-benzoylpyridine and 4-acetylpyridine. Binuclear, $Mo_2O_4Cl_2(X-py)_4{\cdot}2H_2$ prepared from hydrolysis of $(X-pyH)_2[MoOCl_5]{\cdot}H_2O$ were diamagnetic and nonelectrolytes. The anion of $(X-pyH)_4$[$Mo_2O_4(NCS)_6)$]${\cdot}H_2$O was formulated as dimer and electrolyte.

  • PDF

The Photovoltaic Effect of Iodine-Doped Metal Free Phthalocyanine/ZnO System (Ⅰ) (요오드가 도핑된 무금속 프탈로시아닌/산화아연계의 광기전력 효과(Ⅰ))

  • Heur, Soun-Ok;Kim, Young-Soon;Park, Yoon-Chang
    • Journal of the Korean Chemical Society
    • /
    • v.39 no.3
    • /
    • pp.163-175
    • /
    • 1995
  • Metal free phthalocyanine($H_2Pc$) partially doped with iodine, $H_2Pc(I)x$, has been made to improve photosensitizing efficiency of ZnO/$H_2Pc$. The content of iodine dopant level(x) for $H_2Pc(I)x$ upon $H_2Pc$ polymorphs was characterized as ${\chi}-H_2Pc(I)_{0.92}$ and ${\beta}-H_2Pc(I)_{0.96}$ by elemental analysis. Characterization of iodine-oxidized $H_2Pc$ were investigated by TGA (thermogravimetric analysis), UV-Vis, FT-IR, Raman and ESR (electron spin resonance) spectrum, and the adsorption properties of $H_2Pc(I)x$ on ZnO were characterized by means of Raman and ESR studies. TGA for $H_2Pc(I)x$ showed a complete loss of iodine at approximately 265$^{\circ}C$ and the Raman spectrum of $H_2Pc(I)x$ and ZnO/$H_2Pc(I)x$ at 514.5 nm showed characteristic $I_3^-$ patterns in the frequency region 90∼550 $cm^{-1}$. ZnO/$H_2Pc(I)x$ exhibited a very intense and narrow ESR signal at $g=2.0025{\pm}0.0005$ compared to $H_2Pc$/ZnO. Iodine doped ZnO/$H_2Pc(I)x$ showed a better photosensitivity compared to iodine undoped ZnO/$H_2Pc$. That is, the surface photovoltage of ${\chi}-H_2Pc(I)_{0.92}$/ZnO was approximately 31 times greater than that of ZnO/${\chi}-H_2Pc$ and ZnO/${\beta}-H_2Pc(I)_{0.96}$ was 5 times more efficient than ZnO/${\beta}-H_2Pc$ at 670 nm. And the dependence of photosensitizing effect upon $H_2Pc$ polymorphs was exhibited that the surface photovoltage of ZnO/${\chi}-H_2Pc(I)_{0.92}$ was approximately 5 times greater than ZnO/${\beta}-H_2Pc(I)_{0.96}$ at 670 nm. Therefore Iodine doping of H_2Pc$ resulted in increase in photoconductivity of $H_2Pc$ and photovoltaic effect of ZnO/$H_2Pc$ in the visible region.

  • PDF

Semiconductor type micro gas sensor for $H_2$ detection using a $SnO_2-Ag_2O-PtO_x$ system by screen printing technique (스크린 프린팅 기법을 이용한 $SnO_2-Ag_2O-PtO_x$계 반도체식 마이크로 수소 가스센서에 관한 연구)

  • Kim, Il-Jin;Han, Sang-Do;Lee, Hi-Deok;Wang, Jin-Suk
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.17 no.1
    • /
    • pp.69-74
    • /
    • 2006
  • Thick film $H_2$ sensors were fabricated using $SnO_2$ loaded with $Ag_2O$ and $PtO_x$. The composition that gave the highest sensitivity for $H_2$ was in the weight% ratio of $SnO_2 : PtO_x : Ag_2O$ as 93 : 1 : 6. The nano-crystalline powders of $SnO_2$ synthesized by sol-gel method were screen printed with $Ag_2O$ and $PtO_x$ on alumina substrates. The fabricated sensors were tested against gases like $H_2$, $CH_4$, $C_3H_8$, $C_2H_5OH$ and $SO_2$. The composite material was found sensitive against $H_2$ at the working temperature $130^{\circ}C$, with minor interference of other gases. The $H_2$ gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on $SnO_2-Ag_2O-PtO_x$ system exhibited the high performance, high selectivity and very short response time to $H_2$ at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of $H_2$.

Temperature and Ligand Effects on the Eu(Ⅲ) Emission Spectra in the Aqueous Solution (수용액에서의 Eu(Ⅲ) 착물의 형광스펙트럼에 영향을 미치는 온도 및 리간드 효과에 관한 연구)

  • Lee, In Suk;Kim, Geon
    • Journal of the Korean Chemical Society
    • /
    • v.34 no.6
    • /
    • pp.548-554
    • /
    • 1990
  • Temperature effects on the fluorescence emission spectra of 0.01 M Eu(III) ion with ClO$_4$, Cl$^-$, NO$_3$ were studied. Relative intensity change of hypersensitive band ($^5D0\; {\to}\;^7F_2$) and nonhypersensitive band ($^5D0 \;{\to}\;^7F_1$) was quite remarkable with temperature and ligand. The relative intensity change was interpreted as the change of formation constant and used to calculation the enthalpy change of $Eu(H_2O)_X^{3+}$+ to EuL(H$_2O)_{X-1}^{2+}$ complex. $\Delta{H}$ of $Eu(H_2O)_X^{3+}$ to EuCl(H$_2O)_{X-1}^{2+}$ was roughly 15 kJ/mol and temperature independent, but $\Delta{H}$ of EuNO$_3(H_2O)_{X-1}^{2+}$ was changed with temperature; -11 kJ/mol at 25$^{\circ}C$ and 47 kJ/mol at 250$^{\circ}C$.

  • PDF

On The Size of The Subgroup Generated by Linear Factors (선형 요소에 의해 생성된 부분그룹의 크기에 관한 연구)

  • Cheng, Qi;Hwang, Sun-Tae
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.45 no.6
    • /
    • pp.27-33
    • /
    • 2008
  • Given a polynomial ${\hbar}(x){\in}F_q[x]$ of degree h, it is an important problem to determine the size of multiplicative subgroup of $\(F_q[x]/({\hbar(x))\)*$ generated by $x-s_1,\;x-s_2,\;{\cdots},\;x-s_n$, where $\{s_1,\;s_2,\;{\cdots},\;s_n\}{\sebseteq}F_q$, and for all ${\hbar}(x){\neq}0$. So far the best known asymptotic lower bound is $(rh)^{O(1)}\(2er+O(\frac{1}{r})\)^h$, where $r=\frac{n}{h}$ and e(=2.718...) is the base of natural logarithm. In this paper, we exploit the coding theory connection of this problem and prove a better lower bound $(rh)^{O(1)}\(2er+{\frac{e}{2}}{\log}r-{\frac{e}{2}}{\log}{\frac{e}{2}}+O{(\frac{{\log}^2r}{r})}\)^h$, where log stands for natural logarithm We also discuss about the limitation of this approach.

The Rate of Superoxide Radical (${O_2}^-$.) Production in Normal Fenton's Reagent at Different pHs (펜톤반응에서 pH의 변화에 따른 superoxide radical (${O_2}^-$.)의 생성)

  • 김용수;공성호;김재호
    • Journal of Soil and Groundwater Environment
    • /
    • v.7 no.2
    • /
    • pp.73-81
    • /
    • 2002
  • In normal Fenton's reagent, the reductive mechanism of carbon tetrachloride (CT) with superoxide radical (${O_2}^-$.) was observed and the rate of ${O_2}^-$. production was investigated as a function of $H_2O$$_2$ concentration and pH. As pH was increased, the rate of 1-hexanol degradation was rapidly decreased from 90% (at pH 3) to 5% (at pH 11). On the other hand, more degradation of carbon tetrachloride was observed at higher pH regimes indicating Fenton's reaction is an oxidant-reductant co-existing system at neutral pHs. The rate of $O_2^{-}$ . production was observed at different $H_2$$O_2$ concentrations and at different pHs. The rate increased from (45.3$\pm$7.8) x $10^{-6}$ M/s to (151.0$\pm$26.2) x $10^{-6}$ M/s ($294mM H_2$$O_2$) at pH 11: the rate 3150 increased from (22.1$\pm$3.8) x $10^{-6}$ M/s at pH 7 to (151.0$\pm$26.2) x $^10{-6}$ M/s at pH 11 with 294mM $H_2$$O_2$, These results showed that Fenton's reagent could be applied at wide pH regimes. Especially, carbon tetrachloride, which can not be easily adsorbed to soils and then can be dissolved into groundwater causing a cancer, could be efficiently treated by Fenton's reagent.reagent.

Dispersion of SmxCe1-xO2-2/x Nanoparticles which is Synthesized by Hydrothermal Process in Aqueous System (수열합성법으로 합성된 나노 SmxCe1-xO2-2/x 분말의 수계 분산)

  • Bae Dong-Sik;Kim Eun-Jung;Han Kyong-Sop
    • Korean Journal of Materials Research
    • /
    • v.15 no.2
    • /
    • pp.112-114
    • /
    • 2005
  • Dispersion stability of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles, which was produced by hydrothermal process, was studied in aqueous suspension using ESA (Eletrokinetic Sonic Amplitude). The average particle size of the synthesized $Sm_xCe_{1-x}O_{2-2/x}$ at nanoparticles was about $5{\pm}2nm$. The dispersion and rheological behavior of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles aqueous suspension was investigated using $NH_4OH\;and\;HNO_3$ as a disperse agent. The colloidal stability of aqueous suspensions with $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles at different pH values has been investigated by means of zeta potential, average particle size, and the distribution of synthesized $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles. The isoelectric point of the $Sm_xCe_{1-x}O_{2-2/x}$ nanoparticles was at pH around 11 and the value of zeta potential was at its maximum near pH 6.5.

Optimization and Development of Prediction Model on the Removal Condition of Livestock Wastewater using a Response Surface Method in the Photo-Fenton Oxidation Process (Photo-Fenton 산화공정에서 반응표면분석법을 이용한 축산폐수의 COD 처리조건 최적화 및 예측식 수립)

  • Cho, Il-Hyoung;Chang, Soon-Woong;Lee, Si-Jin
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.30 no.6
    • /
    • pp.642-652
    • /
    • 2008
  • The aim of our research was to apply experimental design methodology in the optimization condition of Photo-Fenton oxidation of the residual livestock wastewater after the coagulation process. The reactions of Photo-Fenton oxidation were mathematically described as a function of parameters amount of Fe(II)($x_1$), $H_2O_2(x_2)$ and pH($x_3$) being modeled by the use of the Box-Behnken method, which was used for fitting 2nd order response surface models and was alternative to central composite designs. The application of RSM using the Box-Behnken method yielded the following regression equation, which is an empirical relationship between the removal(%) of livestock wastewater and test variables in coded unit: Y = 79.3 + 15.61x$_1$ - 7.31x$_2$ - 4.26x$_3$ - 18x$_1{^2}$ - 10x$_2{^2}$ - 11.9x$_3{^2}$ + 2.49x$_1$x$_2$ - 4.4x$_2$x$_3$ - 1.65x$_1$x$_3$. The model predicted also agreed with the experimentally observed result(R$^2$ = 0.96) The results show that the response of treatment removal(%) in Photo-Fenton oxidation of livestock wastewater were significantly affected by the synergistic effect of linear terms(Fe(II)($x_1$), $H_2O_2(x_2)$, pH(x$_3$)), whereas Fe(II) $\times$ Fe(II)(x$_1{^2}$), $H_2O_2$ $\times$ $H_2O_2$(x$_2{^2}$) and pH $\times$ pH(x$_3{^2}$) on the quadratic terms were significantly affected by the antagonistic effect. $H_2O_2$ $\times$ pH(x$_2$x$_3$) had also a antagonistic effect in the cross-product term. The estimated ridge of the expected maximum response and optimal conditions for Y using canonical analysis were 84 $\pm$ 0.95% and (Fe(II)(X$_1$) = 0.0146 mM, $H_2O_2$(X$_2$) = 0.0867 mM and pH(X$_3$) = 4.704, respectively. The optimal ratio of Fe/H$_2O_2$ was also 0.17 at the pH 4.7.

A Study on charge/discharge characteristics of cathode active material $LiCo_{1-x}Ni_{x}O_2$ for Li rechargeable batteries (리튬 2차 전지용 정극 활물질 $LiCo_{1-x}Ni_{x}O_2$의 충방전 특성)

  • 정인성;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.228-231
    • /
    • 1996
  • We prepared $LiCo_{1-x}Ni_{x}O_2$ by reacting stoichiometric mixture of LiOH.$H_2O$, $CoCO_3$.$xH_2O$ and $Ni(OH)_2$ (mole ratio respectively) and heating at $850^{\circ}C$ for 5h. We awared through XRD that from 0 to 0.5 at x in $LiCo_{1-x}Ni_{x}O_2$ is well formed for hexagonal structure, but the more $LiCo_{1-x}Ni_{x}O_2$ involve NI, the more hexagonal structure is not well formed. In the result of charge/discharge test, charge/discharge characteristic of $LiCo_{1-x}Ni_{x}O_2$ is similar to that of $LiCoO_2$. Therefore, $LiCo_{1-x}Ni_{x}O_2$ is superior to $LiCoO_2$ for Li secondary battery

  • PDF