物理化学学报 >> 1990, Vol. 6 >> Issue (02): 139-145.doi: 10.3866/PKU.WHXB19900204

研究论文 上一篇    下一篇

铀酰离子发光双指数衰减的研究

王志麟; 郑企克; 吴节强   

  1. 复旦大学激光化学教研室
  • 收稿日期:1988-08-27 修回日期:1989-02-23 发布日期:1990-04-15
  • 通讯作者: 王志麟

Bi-Exponential Decay of the Luminescence of Electronically Excited Uranyl Ions

Wang Zhi-Lin; Zheng Qi-Ke; Wu Jie-Qiang   

  1. Laser Chemistry Laboratory Fudan University
  • Received:1988-08-27 Revised:1989-02-23 Published:1990-04-15
  • Contact: Wang Zhi-Lin

摘要: 本文系统地研究了铀酰离子发光双指数衰减时的时间分辨发光光谱, 测定和研究了相应条件下铀(Ⅵ)的激光拉曼光谱. 通过计算机对所得光谱进行定量的拟合分解表明, 铀(Ⅵ)的发光双指数衰减是两种发光体UO_2~(2+)和它的水解产物(UO_2)_2(OH)_2~(2+)发光叠加的结果。

Abstract: The bi-exponential decay of the luminescence of electronically excited uranyl ions in perchloric acid has been investigated with detailed study of the time resolved lu-minescence spectra and Raman spectra of uranium. While the U(Ⅵ) concentration is in the range of 0.01-0. 1 molL~(-1) and the pH is≤1.5, the luminescence decay is sin-gle exponential and the luminescence spectra are independent on the delay time and the U(Ⅵ) concentration with peaks at 488.0, 510.0, and 533.0 nm, which belong toaquo-uranyl ions. While the pH of the solution is increased to higher than 2.8, the luminescence undergoes bi-exponential decay and the luminescence spectra with 0.2 μs delay time change dramatically with increasing the pH and the U(VI) concentration, and are different from the spectra with 20 μs time delay, which consist of three peaks at 500.0, 518.0, and 538.0 nm. From the thermodynamic data of the hydrolysis of uranyl ions and the dependence of the Raman spectra of U(VI) on the pH and the uranium concentration the later spectra can be identified as the spectra of the dinuclear hydrolysis product of UO~(2+)_2 and (UO_2)_2(OH)~(2+)_2. All the measured time resolved spectra can be fitted to the linear combination of the spectra of aquo-uranyl ions and (UO_2)~(2+)_2(OH)~(2+)_2 satisfatorily. The conclusion that the bi-exponential decay is attributed to UO_2(H_2O)~(2+)_x and (UO_2)_2(OH)~(2+)_2 ions has been withdrawn.