TY - JOUR

T1 - Photophysics and photochemistry of uranyl ions in aqueous solutions

T2 - Refining of quantitative characteristics

AU - Filippov, T. N.

AU - Kolin’ko, P. A.

AU - Kozlov, D. V.

AU - Glebov, E. M.

AU - Grivin, V. P.

AU - Plyusnin, V. F.

PY - 2016/3/1

Y1 - 2016/3/1

N2 - The photochemistry and photophysics of aqueous solutions of uranyl nitrate have been investigated by nanosecond laser photolysis with excitation at 266 and 355 nm and by time-resolved fluorescence spectroscopy. The quantum yield has been determined for (UO2 2+)* formation under excitation with λ = 266 and 355 nm light (φ = 0.35). The quantum yield of uranyl luminescence under the same conditions is 1 × 10–2 and 1.2 × 10–3, respectively, while the quantum yield of luminescence in the solid state is unity, irrespective of the excitation wavelength. The decay of (UO2 2+)* in the presence of ethanol is biexponential. The rate constants of this process at pH 3.4 are k1 = (2.7 ± 0.2) × 107 L mol–1 s–1 and k2 = (5.4 ± 0.2) × 106 L mol–1 s–1. This biexponential behavior is explained by the existence of different complex uranyl ion species in the solution. The addition of colloidal TiO2 to the solution exerts no effect on the quantum yield of (UO2 2+)* formation or on the rate of the reaction between (UO2 2+)* and ethanol. The results of this study have been compared with data available from the literature.

AB - The photochemistry and photophysics of aqueous solutions of uranyl nitrate have been investigated by nanosecond laser photolysis with excitation at 266 and 355 nm and by time-resolved fluorescence spectroscopy. The quantum yield has been determined for (UO2 2+)* formation under excitation with λ = 266 and 355 nm light (φ = 0.35). The quantum yield of uranyl luminescence under the same conditions is 1 × 10–2 and 1.2 × 10–3, respectively, while the quantum yield of luminescence in the solid state is unity, irrespective of the excitation wavelength. The decay of (UO2 2+)* in the presence of ethanol is biexponential. The rate constants of this process at pH 3.4 are k1 = (2.7 ± 0.2) × 107 L mol–1 s–1 and k2 = (5.4 ± 0.2) × 106 L mol–1 s–1. This biexponential behavior is explained by the existence of different complex uranyl ion species in the solution. The addition of colloidal TiO2 to the solution exerts no effect on the quantum yield of (UO2 2+)* formation or on the rate of the reaction between (UO2 2+)* and ethanol. The results of this study have been compared with data available from the literature.

KW - intermediate absorption

KW - laser flash photolysis

KW - quantum yield

KW - time-resolved fluorescence

KW - titanium dioxide

KW - uranyl nitrate

UR - http://www.scopus.com/inward/record.url?scp=84979502875&partnerID=8YFLogxK

U2 - 10.1134/S0023158416020026

DO - 10.1134/S0023158416020026

M3 - Article

AN - SCOPUS:84979502875

VL - 57

SP - 191

EP - 199

JO - Kinetics and Catalysis

JF - Kinetics and Catalysis

SN - 0023-1584

IS - 2

ER -