铀酰离子发光双指数衰减的研究  

BI-EXPONENTIAL DECAY OF THE LUMINESCENCE OF ELECTRONICALLY EXCITED URANYL IONS

作　　者：王志麟[1] 郑企克[1] 吴节强 

机构地区：[1]复旦大学激光化学研究室

出　　处：《物理化学学报》1990年第2期139-145,共7页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金

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。The bi-exponential decay of the luminescence of electronically excited uranyl ionsin 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 isin 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 andthe 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, theluminescence undergoes bi-exponential decay and the luminescence spectra with 0.2μsdelay time change dramatically with increasing the pH and the U(Ⅵ) concentration,and are different from the spectra with 20μs time delay, which consist of three peaksat 500.0, 518.0, and 538. 0nm. From the thermodynamic data of the hydrolysis ofuranyl ions and the dependence of the Raman spectra of U(Ⅵ) on the pH and theuranium concentration the later spectra can be identified as the spectra of the dinu-clear hydrolysis product of UO_2^(2+) and (UO_2)_2(OH)_2^(2+). All the measured time resolvedspectra can be fitted to the linear combination of the spectra of aquo-uranyl ions and(UO_2)_2(OH)_2^(2+) satisfatorily. The conclusion that the bi-exponential decay is attributedto UO_2(H_2O)_x^(2+) and (UO_2)_2(OH)_2^(2+) ions has been withdrawn.

关 键 词：铀铣离子 发光 双指数衰减 

分 类 号：O614.62[理学—无机化学]