Photo-enhancement Effect on Oxidation Reaction of Uranium (IV) by NO^-_3 in Perchloric Acid Solutions

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Kinetic studies on the oxidation reactions of U(IV) by NO<SUP>-</SUP><SUB>3</SUB> in HClO<SUB>4</SUB> solutions have been carried out spectrophotometrically in the dark and under irradiation with Xe light. Remarkable photo-enhancement effect on the oxidation reaction was observed under the irradiation with UV light below 420nm. This indicates that the photo-enhanced oxidation of U(IV) is not due to the excitation of U(IV) but the excitation of NO-3. It was found that apparent first-order rate constants in both dark (κ<SUB>obs</SUB>) and photo-reactions (κ<SUP>*</SUP><SUB>obs</SUB>) increase with increasing [NO<SUP>-</SUP><SUB>3</SUB>] and approach to constant values. This relation is well correlated with the distribution of nitrato complexes of U(IV). Furthermore, the oxidation rates were found to be independent of [H+](0.5-3.5M(=mol•dm<SUP>-3</SUP>)). From these results, it is proposed that the oxidation of U(IV) by NO<SUP>-</SUP><SUB>3</SUB> proceeds through two paths, i.e., one is the two-electron transfer between U(IV)[U<SUP>4+</SUP> and U(NO<SUB>3</SUB>)<SUP>3+</SUP> species] and NO<SUP>-</SUP><SUB>3</SUB>, and another is the oxygen atom transfer from the coordinated NO<SUP>-</SUP><SUB>3</SUB> to U(IV) in U(NO<SUB>3</SUB>)<SUP>2+</SUP><SUB>2</SUB>. Kinetic parameters are as follows: κ<SUB>obs</SUB>(25°C)=7.0×10<SUP>-6</SUP> s<SUP>-1</SUP>, ΔH<SUP>≠</SUP>=60.8kJ•mol<SUP>-1</SUP>, ΔS<SUP>≠</SUP>=-140J.K<SUP>-1</SUP>.mol<SUP>-1</SUP> and κ<SUP>*</SUP><SUB>obs</SUB>(25°C)=3.0×10<SUP>-5</SUP>s<SUP>-1</SUP>, ΔH<SUP>≠</SUP>=26.3kJ.mol<SUP>-1</SUP>, ΔS<SUP>≠</SUP>=-243J.K<SUP>-1</SUP>.mol<SUP>-1</SUP>.

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  • Journal of nuclear science and technology

    Journal of nuclear science and technology 34(7), 695-699, 1997-07-25

    Atomic Energy Society of Japan

参考文献:  20件中 1-20件 を表示

  • <no title>

    GANGWER T.

    BNL 50715, 1977

    被引用文献3件

  • <no title>

    GOLDSTAIN M.

    Nucl. Eng. Int. 22, 69, 1977

    被引用文献1件

  • <no title>

    BELL T.

    Radiochim. Acta 25, 225, 1978

    被引用文献1件

  • <no title>

    OHNO S.

    Nihon Genshiryoku-Gakkai Shi (J. At. Energy Soc. Jpn. ) 28, 933, 1986

    被引用文献1件

  • <no title>

    ENOKIDA Y.

    NEUT. Res. Rep. 87, 1987

    被引用文献1件

  • <no title>

    KEMP T. J.

    Inorg. Chem. 25, 3840, 1986

    被引用文献1件

  • <no title>

    PARK T. -Y.

    J. Nucl. Sci. Technol. 28, 418, 1991

    被引用文献1件

  • <no title>

    WADA Y.

    J. Nucl. Sci. Technol. 32, 1018, 1995

    被引用文献1件

  • <no title>

    TSUSHIMA S.

    J. Nucl. Sci. Technol. 33, 810, 1996

    被引用文献1件

  • <no title>

    GORDON G.

    Inorg. Chem. 1, 69, 1962

    被引用文献1件

  • <no title>

    BUCHACEK R.

    Inorg. Chem. 11, 2154, 1972

    被引用文献1件

  • <no title>

    SLADE A. L.

    DP-554 12, 1961

    被引用文献1件

  • <no title>

    HOGFELDT E.

    Stability Constants of Metal-Ion Complexes Part A : Inorganic Ligands, 1992

    被引用文献1件

  • <no title>

    PARK Y. -Y.

    Chem. Lett. 1329, 1991

    被引用文献1件

  • <no title>

    PARK Y. -Y.

    J. Nucl. Sci. Technol. 29, 866, 1992

    被引用文献2件

  • <no title>

    STREHLOW H.

    Z. Phys. Chem. Neue Floge 132, 151, 1982

    被引用文献1件

  • <no title>

    WARNECK P.

    J. Phys. Chem. 92, 6278, 1988

    被引用文献1件

  • <no title>

    KATSUMURA Y.

    J. Phys. Chem. 95, 4435, 1991

    被引用文献2件

  • <no title>

    DEPOORTER G. L.

    Actinide Separations 267, 1980

    被引用文献1件

  • Photochemically-Induced Valency Adjustment of Plutonium and Neptunium in Nitric Acid Solution Using Mercury Lamp.

    WADA Yukio , WADA Kouji , GOIBUCHI Takayuki , TOMIYASU Hiroshi

    Journal of Nuclear Science and Technology 31(7), 700-710, 1994

    J-STAGE 被引用文献3件

各種コード

  • NII論文ID(NAID)
    10002077561
  • NII書誌ID(NCID)
    AA00703720
  • 本文言語コード
    ENG
  • 資料種別
    ART
  • ISSN
    00223131
  • NDL 記事登録ID
    4260278
  • NDL 雑誌分類
    ZM35(科学技術--物理学)
  • NDL 請求記号
    Z53-A460
  • データ提供元
    CJP書誌  NDL  J-STAGE 
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