The Relationship between reduction and deposition of uranium

Ouchi, Kazuki  ; Otobe, Haruyoshi  ; Kitatsuji, Yoshihiro  

We investigated the relationship between the quantity of electricity of electrolytic reduction of U(VI) to U(IV) and the deposition on the electrode surface by measuring electrochemical quartz crystal microbalance of U(IV) deposits following the electrolytic reduction of U(VI) to U(V) in a pH4 solution. We found that the deposition can be divided into the two phases after starting deposition according to variation between electric quantity and deposition amount. This variation indicates that the species of deposits in first and second phase are highly likely to be U(IV) hydroxide (U(OH)) and UO, respectively. From this result, we propose the deposition mechanism that a U hydroxide forms as an intermediate and transforms to U oxide as a terminal product.