The determination from the Mott-Schottky plots of the flat-band potential of UO2 nuclear fuel in contact with alkaline solutions

Electrochemical studies of the nuclear fuels are predicated on their ability to conduct significant electrical current. The electrochemical proprieties of UO2+x (as well as UO2 - used fuel) should thus exhibit some parallels of p-type semiconductors. Flat band potential is measurement at a semiconductor/solution interphase. If effects of surface states are negligible, potential drop associated with the space charge in semiconductor, vanishes as charge on the semiconductor becomes zero. The potential of semiconductor corresponding to this condition is flat potential, which plays the same role as the potential of zero charge for metals.The flat band potential (Efb) were determined from the Mott-Schottky plot (1/C2 vs. E) on a UO2 electrode (pellets of UO2). In our experiments using the Princeton Research Model PARSTAT 2273 Electrochemical System the electrode material was stoichiometric natural UO2. (author)