Naslov
Redox and Adsorption Processes of Hydrolyzed Uranyl Species on a Mercury Electrode from Sodium Chloride Solutions

Autori
Djogić, Renata ; Krznarić, Damir ; Branica, Marko

Izvornik
Electroanalysis (1040-0397) 9 (1997), 12; 936-940

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
uranyl(VI)-ion; hydrolysis; adsorption

Sažetak
Reduction and adsorption processes of hydrolyzed uranyl species on the mercury drop electrode, from 0.55 mol L-1 NaCl, were studied by electrochemical cathodic stripping techniques: cyclic voltammetry, alternating current voltammetry, chronoamperometry and double potential step chronocoulometry. The only uranyl species adsorbed on the Hg electrode (between pH 5 and 7) was found to be uncharged uranyl dihydroxide, as well as its reduction product. At bulk concentrations between 3 and 5 mmol L-1, the reactant forms an adsorbed compact film as a result of surface polymerization, nucleation or other condensation process. The adsorption isotherm at pH 6.2 and -0.2 V was measured. It was fitted with Frumkin type isotherm. At the plateau, a reduction current corresponding to 6.7x10-9 mol cm-2 of uranyl ions was measured. This represents on the average 7 adsorbed layers of UO2(OH)2o, presuming an orthorhombic crystal cell structure. Multilayer adsorption is certain even if a polymeric form of uranyl dihyroxide was considered.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA