Square-wave cathodic stripping voltammetry of hydrolyzed uranyl species

Adsorption of uranyl-hydroxo species has been studied using square-wave cathodic stripping voltammetry (SWCSV). The peak of the uranyl ion between pH 5 and 8 has the characteristic features of a reduction complicated with reactant adsorption. The reduction process is totally irreversible, with an average transfer coefficient α = 0.47. The adsorbed species was found to be most probably UO2(OH)02, after correlation of the experimental results with the calculated ionic distribution in the solution. The experimental conditions for the lowest detection limit are given and it amounts to 2 × 10−8 mol l−1 of uranyl hydroxo species. The maximum surface concentration is determined, to be Γ = (2.6 ± 0.1) × 10−10 mol cm−2.