铀酰离子光化学研究——(Ⅲ)Ar~+激光对甲酸体系U(Ⅵ)的光化学还原

PHOTOCHEMICAL REDUCTION OF U(Ⅵ) IN THE FORMIC ACID SOLUTION BY ARGON ION LASER.

摘要: <正> 用Ar~+激光器的4880A作光源,研究了各种因素对光化学还原U(Ⅵ)的量子产额Φ的影响。当U(Ⅵ)=0.05M,HCOOH<3M,Φ随HCOOH增大而增大;HCOOH>3M,Φ趋近于0.47;HCOOH<0.01M,Φ很小。但I_f~0/I_f与HCOOH呈线性关系,K_(sv)=388M~(-1),表明HCOOH对UO_2~(2+)荧光有强烈的物理猝灭作用。当U(Ⅵ)=0.05M,并维持HCOOH/NaCOOH=5,Φ随NaCOOH增大而增大,并趋近于0.5。同时

Abstract: The effect of the concentration of fomic acid, formate, uranyl, nitric acid, nitrate and temperature on the quantum yield (Φ) of photochemical reduction of U(Ⅵ) is studied using 4880 A radiation from argon ion laser. The Φ increases with the fraction (α) of uranium (Ⅵ)-formate complex, α→1,Φ→0.5. The plot of log(dc/dt) vs. log HCOO- (U(Ⅵ)>> HCOO-) or log U(Ⅵ) (HCOO->>U(Ⅵ)) is a straight line with a slop close to unity.