PHOTOREDUCTION OF URANYL IONS IN SULFURIC ACID MEDIUM WITH LASER

The photoreduction of uranyl ions in sulfuric acid with a CW He-Cd laser at 4416 A has been investigated. A quantum yield of 0.69+0.02 is obtained for the production of U (IV) at 25℃. The effect of the concentrations of ethanol, sulfuric acid and uranyl ion on the quantum yield has been discussed. If U (VI) >7.0×10-3M, C2H5OH> 0.5M, and H2SO4>2.0M, the concentration effects for quantum yield are negligible. The dependence of reaction rate on the concentrations of sulfuric acid and uranyl ion has been studied. The rate of production of U (IV) depends on the concentration of H+ and UO22+ and the corresponding rate equation iswith a and b equal to 0.16 and 1.3 respectively. The apparent rate constant, k (M, sec, mW), is calculated to be 4.1×10-5 at 25℃.